MySQL 5.7 Release Notes
MySQL 5.7 Release Notes
Abstract
This document contains release notes for the changes in each release of MySQL 5.7, up through MySQL 5.7.21.
For information about changes in a different MySQL series, see the release notes for that series.
For additional MySQL 5.7 documentation, see the MySQL 5.7 Reference Manual, which includes an overview
of features added in MySQL 5.7 (What Is New in MySQL 5.7), and discussion of upgrade issues that you may
encounter for upgrades from MySQL 5.6 to MySQL 5.7 (Changes Affecting Upgrades to MySQL 5.7).
Updates to these notes occur as new product features are added, so that everybody can follow the development
process. If a recent version is listed here that you cannot find on the download page (http://dev.mysql.com/
downloads/), the version has not yet been released.
The documentation included in source and binary distributions may not be fully up to date with respect to release
note entries because integration of the documentation occurs at release build time. For the most up-to-date
release notes, please refer to the online documentation instead.
For legal information, see the Legal Notices.
For help with using MySQL, please visit either the MySQL Forums or MySQL Mailing Lists, where you can discuss
your issues with other MySQL users.
For additional documentation on MySQL products, including translations of the documentation into other
languages, and downloadable versions in variety of formats, including HTML and PDF formats, see the MySQL
Documentation Library.
Document generated on: 2017-09-07 (revision: 12722)
Table of Contents
Preface and Legal Notices ............................................................................................................ 2
Changes in MySQL 5.7.21 (Not yet released, General Availability) .................................................. 3
Changes in MySQL 5.7.20 (Not yet released, General Availability) .................................................. 3
Changes in MySQL 5.7.19 (2017-07-17, General Availability) ......................................................... 3
Changes in MySQL 5.7.18 (2017-04-10, General Availability) ....................................................... 12
Changes in MySQL 5.7.17 (2016-12-12, General Availability) ....................................................... 21
Changes in MySQL 5.7.16 (2016-10-12, General Availability) ....................................................... 29
Changes in MySQL 5.7.15 (2016-09-06, General Availability) ....................................................... 30
Changes in MySQL 5.7.14 (2016-07-29, General Availability) ....................................................... 33
Changes in MySQL 5.7.13 (2016-06-02, General Availability) ....................................................... 40
Changes in MySQL 5.7.12 (2016-04-11, General Availability) ....................................................... 48
Changes in MySQL 5.7.11 (2016-02-05, General Availability) ....................................................... 54
Changes in MySQL 5.7.10 (2015-12-07, General Availability) ....................................................... 65
Changes in MySQL 5.7.9 (2015-10-21, General Availability) ......................................................... 73
Changes in MySQL 5.7.8 (2015-08-03, Release Candidate) ......................................................... 97
Changes in MySQL 5.7.7 (2015-04-08, Release Candidate) ........................................................ 131
Changes in MySQL 5.7.6 (2015-03-09, Milestone 16) ................................................................. 141
Changes in MySQL 5.7.5 (2014-09-25, Milestone 15) ................................................................. 179
Changes in MySQL 5.7.4 (2014-03-31, Milestone 14) ................................................................. 215
Changes in MySQL 5.7.3 (2013-12-03, Milestone 13) ................................................................. 239
Changes in MySQL 5.7.2 (2013-09-21, Milestone 12) ................................................................. 258
Changes in MySQL 5.7.1 (2013-04-23, Milestone 11) ................................................................. 299
Changes in MySQL 5.7.0 (Not released, Milestone 10) ............................................................... 319
Index ........................................................................................................................................ 326
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MySQL 5.7 Release Notes
Preface and Legal Notices
This document contains release notes for the changes in each release of MySQL 5.7, up through
MySQL 5.7.21.
Legal Notices
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to other formats is allowed as long as the actual content is not altered or edited in any way. You shall
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MySQL 5.7 Release Notes
not publish or distribute this documentation in any form or on any media, except if you distribute the
documentation in a manner similar to how Oracle disseminates it (that is, electronically for download
on a Web site with the software) or on a CD-ROM or similar medium, provided however that the
documentation is disseminated together with the software on the same medium. Any other use, such
as any dissemination of printed copies or use of this documentation, in whole or in part, in another
publication, requires the prior written consent from an authorized representative of Oracle. Oracle and/
or its affiliates reserve any and all rights to this documentation not expressly granted above.
Changes in MySQL 5.7.21 (Not yet released, General Availability)
Version 5.7.21 has no changelog entries, or they have not been published because the product version
has not been released.
Changes in MySQL 5.7.20 (Not yet released, General Availability)
Version 5.7.20 has no changelog entries, or they have not been published because the product version
has not been released.
Changes in MySQL 5.7.19 (2017-07-17, General Availability)
• Account Management Notes
• Compilation Notes
• Deprecation and Removal Notes
• Packaging Notes
• Security Notes
• Spatial Data Support
• Test Suite Notes
• X Plugin Notes
• Platform-Specific Notes
• Functionality Added or Changed
• Bugs Fixed
Account Management Notes
• During data directory initialization or upgrade, MySQL now creates a
'mysql.session'@'localhost' reserved account. This account is used internally by plugins to
access the server. It is locked so that it cannot be used for client connections. (Bug #25642343)
Compilation Notes
• Solaris: On Solaris, MySQL binary distributions are now linked against libatomic.so, so they are
no longer dependent on libstatomic.so. (Bug #25909965)
Deprecation and Removal Notes
• InnoDB: The innodb_undo_logs configuration option is deprecated and will be removed in a
future release. The innodb_rollback_segments configuration option performs the same function
and should be used instead.
The Innodb_available_undo_logs status variable is deprecated and will be removed in a future
release.
3
MySQL 5.7 Release Notes
Packaging Notes
• mysqladmin was added to Docker/Minimal packages because it is needed by InnoDB Cluster. (Bug
#25998285)
• Debian/Ubuntu packages now support multiple MySQL instances with systemd. See Managing
MySQL Server with systemd. (Bug #24559588, Bug #82785)
Security Notes
• Security Fix: The linked OpenSSL library for the MySQL Commercial Server has been updated to
version 1.0.2l. Issues fixed in the new OpenSSL version are described at http://www.openssl.org/
news/vulnerabilities.html.
This change does not affect the Oracle-produced MySQL Community build of MySQL Server, which
uses the yaSSL library instead. (Bug #26160962)
• MySQL Enterprise Edition now supports LDAP pluggable authentication of MySQL users. This
enables MySQL Server to use LDAP (Lightweight Directory Access Protocol) to authenticate
MySQL users by accessing directory services such as X.500. For more information, see Pluggable
Authentication.
• MySQL Enterprise Edition now includes a keyring_aws plugin that communicates with the Amazon
Web Services Key Management Service as a back end for key generation and uses a local file for
key storage. For more information, see The MySQL Keyring.
Spatial Data Support
• These functions previously accepted either WKB strings or geometry arguments. Use of geometry
arguments is now deprecated and generates a warning. Geometry arguments will not be accepted in
MySQL 8.0.
• ST_GeomCollFromWKB(), ST_GeometryCollectionFromWKB()
• ST_GeomFromWKB(), ST_GeometryFromWKB()
• ST_LineFromWKB(), ST_LinestringFromWKB()
• ST_MLineFromWKB(), ST_MultiLinestringFromWKB()
• ST_MPointFromWKB(), ST_MultiPointFromWKB()
• ST_MPolyFromWKB(), ST_MultiPolygonFromWKB()
• ST_PointFromWKB()
• ST_PolyFromWKB(), ST_PolygonFromWKB()
For information about migrating queries that refer to those functions away from using geometry
arguments to using WKB arguments, see Functions That Create Geometry Values from WKB
Values.
Test Suite Notes
• mysql-test-run.pl now has a --test-progress option to cause display of the percentage of
tests remaining. (Bug #25601131, Bug #20755059, Bug #76455)
• These changes were made to the --xml-report option for mysql-test-run.pl:
• A <failure> tag identifies any test failing on a retry attempt.
• Separate statistics and fields are included for skipped and disabled tests.
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MySQL 5.7 Release Notes
• The XML report is created in the build directory if no absolute path is given for out-of-source builds.
• For combination runs, a field named variation is included in the <testcase> tag.
• Results for all tests belonging to a suite are aggregated within a single <testsuite> tag.
• Information regarding failures is reported with a brief reason in an attribute named message, along
with other details within the tag.
(Bug #25349924)
• mysql-test-run.pl now supports a --report-unstable-tests option that has these effects:
• Reports any test that has passed using at least one retry attempt in a separate category called
“Unstable tests” in the summary.
• If all failures are due to unstable tests, mysql-test-run.pl produces a warning but exits
successfully.
• Adds a new XML tag to report unstable tests, if the --xml-report option is also specified.
(Bug #24473420, Bug #25984429)
• mysqltest now supports a replace_numeric_round command that takes an argument value
from 0 to 16 indicating the number of decimals to round numeric values to. This can be used to help
prevent result content mismatch errors for tests in which slightly different results are obtained across
platforms due to precision differences. Thanks to Daniel Black for the patch. (Bug #23280117, Bug
#81399)
X Plugin Notes
• X Plugin now handles expired SSL certificates correctly. (Bug #25835833)
• The output of clauses such as GROUP BY and HAVING has been improved by moving the
grouping_criteria expression to the derived query. (Bug #25549637, Bug #24497007)
Platform-Specific Notes
• Linux: The generic Linux build for MySQL 5.7 is now built on Oracle Linux 6 using glibc 2.12.
Systems that use the build need to have glibc 2.12 or later installed on them. (Bug #26005558)
• Linux: The generic Linux build for MySQL 5.7 now supports Non-Uniform Memory Access (NUMA)
on its host system. Systems that use the build need to have libnuma installed on them. See
Installing MySQL on Unix/Linux Using Generic Binaries for more details. (Bug #26005558)
Functionality Added or Changed
• Replication: The group_replication_transaction_size_limit variable was added
to enable you to protect a group against large transactions causing a failure. (Bug #84785, Bug
#25510757)
• Replication: Group Replication now supports SAVEPOINT SQL transactions.
• RPM .spec files now include support for running unit tests. (Bug #25814143, Bug #85743)
• For Windows, MSI installer packages now include a check for the required Visual Studio
redistributable package, and produce a message asking the user to install it if it is missing. (Bug
#25658832)
• The mysql client now supports a --binary-as-hex option that causes display of binary data
using hexadecimal notation (0xvalue). Thanks to Daniël van Eeden for the patch. (Bug #25340722,
Bug #84391)
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MySQL 5.7 Release Notes
• The audit_log filter parser now produces errors for unexpected JSON elements in filter definitions.
(Bug #24360663)
• The libmysqld embedded server library is deprecated and will be removed in MySQL 8.0. These
are also deprecated and will be removed:
• The mysql_config --libmysqld-libs, --embedded-libs, and --embedded options
• The CMake WITH_EMBEDDED_SERVER, WITH_EMBEDDED_SHARED_LIBRARY, and
INSTALL_SECURE_FILE_PRIV_EMBEDDEDDIR options
• The (undocumented) mysql --server-arg option
• The mysqltest --embedded-server, --server-arg, and --server-file options
• The mysqltest_embedded and mysql_client_test_embedded test programs
Bugs Fixed
• Incompatible Change: Plugins such as Group Replication and X Plugin now use the
mysql.session account added in this version. If you are upgrading from a previous version which
did not include the mysql.session account you must run mysql_upgrade to ensure the account
is created. If mysql_upgrade is not run, plugins fail to start with the error message There was an
error when trying to access the server with user: [email protected]
Make sure the user is present in the server and that mysql_upgrade was run
after a server update. (Bug #26042764)
References: See also: Bug #24311527, Bug #25642343, Bug #25750822, Bug #25103980, Bug
#83841.
• InnoDB: An ALTER TABLE operation that rebuilt an encrypted table did not set the encryption
attribute properly. (Bug #26243264)
• InnoDB: The length of a virtual column field in a virtual index record was less than the expected
template column length. (Bug #25793677)
• InnoDB: The server allocated memory unnecessarily for an operation that rebuilt the table. (Bug
#25573565, Bug #85043)
• InnoDB: With foreign_key_checks disabled, InnoDB incorrectly printed messages to the error
log when operations were performed on a table that referenced a non-existent foreign key. (Bug
#25365223)
• InnoDB: During a TRUNCATE TABLE operation on a file-per-table tablespace, a dictionary operation
lock was released before eviction of dirty pages from the buffer pool, causing a latch order violation.
(Bug #25357789)
• InnoDB: When using an index merge optimizer switch, a SELECT COUNT(*) operation sometimes
returned 0. Partitioning code incorrectly performed a memcpy instead of a column copy of columns
read by the index, causing the wrong records to be copied. (Bug #25332330, Bug #81031)
• InnoDB: After a RENAME TABLE operation that moved a table to a different schema, InnoDB
returned an error on restart indicating that it could not locate the tablespace data file. InnoDB failed
to update INNODB_SYS_DATAFILES data dictionary table during the RENAME TABLE operation.
(Bug #25189192, Bug #84038)
• InnoDB: Loading InnoDB tables required more memory in MySQL 5.7 due primarily to the addition
of in-memory structure members introduced with temporary table optimizations. The in-memory
structure members, only used for temporary tables, are now only allocated as needed. (Bug
#25080442)
• InnoDB: During an ALTER TABLE operation that rebuilt a table containing a virtual column, InnoDB
failed to apply a concurrent insert log record. (Bug #24961167)
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MySQL 5.7 Release Notes
• InnoDB: InnoDB failed to apply the concurrent delete log for an in-place ALTER TABLE operation
due to a virtual column validation issue. (Bug #24960450)
• InnoDB: Changes to the InnoDB recovery process in MySQL 5.7 could require up to three scans
of the redo log during recovery. To reduce the number of scans, the first and second scans were
merged. With this change, there is only one scan unless the redo log record hash table that is
populated by the scan reaches its memory threshold. In this case, a second scan is initiated that
performs a simultaneous scan and apply. (Bug #22963951, Bug #80788)
• Partitioning: When a query performed a reverse-ordered range scan (to satisfy ORDER BY ...
DESC) using index condition pushdown on a partitioned InnoDB table, it could take an unreasonably
long time to finish. This was due to the fact that the condition pushdown check failed to get the
bounds of the range, so that the scan continued to read index tuples until it reached the first value in
the index. (Bug #83470, Bug #24929748)
References: See also: Bug #84107.
• Replication: In the case of delayed initialization of the Group Replication plugin, deployed in singleprimary mode, secondaries were able to get writes through an asynchronous replication channel,
which is not allowed in normal initialization of the Group Replication plugin. (Bug #26314756)
• Replication: With GTIDs generated for incident log events, MySQL error code 1590
(ER_SLAVE_INCIDENT) could not be skipped using the --slave-skip-errors=1590 startup
option on a replication slave. (Bug #26266758)
• Replication: A USE statement that followed a SET GTID_NEXT statement sometimes had no effect.
(Bug #26128931)
• Replication: Groups can now contain members running different server versions to enable you to
do online upgrades of a replication group. The rules for combining members in a group with different
versions are:
• If you have a group with 8.0 members, you cannot add a 5.7 member
• If you have a group with 5.7 members you can add a 8.0 member, but it remains in read-only
mode. Writing to this member is dangerous while the group contains multiple server versions and
should be avoided.
In a single-primary group, if the current primary leaves the group and a new primary must be elected,
the primary is first chosen from the lower version members. If no lower version member is found, the
primary is chosen from newer version members. (Bug #25876807)
• Replication: When binlog_checksum=NONE was set on a MySQL server after startup, and then
Group Replication was started, if an error occurred, the server remained in RECOVERING state and
could not be shut down. (Bug #25793366, Bug #85667)
• Replication: In a Group Replication setup where circular asynchronous replication was implemented
between members of different replication groups, view change log events were repeatedly replicated
between the groups with new generated GTIDs each time. The fix ensures that view change log
events are ignored outside the named replication group where they occur, and never generate new
GTIDs. (Bug #25674926)
References: See also: Bug #26049695, Bug #25928854, Bug #25721175.
• Replication: When first starting the MySQL server following an installation from RPM, passwword
validation plugin is activated by default (true only for RPM installations). If binary logging was
already enabled at this time, the activation was logged, even though plugin activations should not be
recorded in the binary log. (Bug #25672750)
• Replication: In a setup where single-primary Group Replication was combined with asynchronous
replication, for example with S1 and S2 forming a group and with S2 and S3 functioning as master
and slave, secondaries such as S2 were accepting transactions and these could then enter the
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MySQL 5.7 Release Notes
group. The fix prevents secondaries creating an asynchronous replication channel when belonging
to a single-primary group, and Group Replication cannot be started when asynchronous replication is
running. (Bug #25574200, Bug #85047)
References: See also: Bug #86325, Bug #26078602.
• Replication: In the event that a member failed to join a group the member was not stopping and
continued to accept transactions. To avoid this set your members to have super_read_only=1
in the my.cfg file. Group Replication now checks for this setting upon successful start up and sets
super_read_only=0. This ensures that members which do not successfully join a group cannot
accept transactions. (Bug #25474736, Bug #84728)
• Replication: If the binary log on a master server was rotated and a full disk condition occurred on
the partition where the binary log file was being stored, the server could stop unexpectedly. The fix
adds a check for the existence of the binary log when the dump thread switches to next binary log
file. If the binary log is disabled, all binary logs up to the current active log are transmitted to slave
and an error is returned to the receiver thread. (Bug #25076007)
• Replication: Interleaved XA transactions could sometimes deadlock the slave applier when the
transaction isolation level was set to REPEATABLE-READ. (Bug #25040331)
• Replication: If a relay log index file named relay log files that did not exist, RESET SLAVE ALL
sometimes did not fully clean up properly. (Bug #24901077)
• Replication: The slave_skip_errors system variable did not permit error numbers larger than
3000. Thanks to Tsubasa Tanaka for the patch. (Bug #24748639, Bug #83184)
• Replication: mysqlbinlog, if invoked with the --raw option, does not flush the output file until
the process terminates. But if also invoked with the --stop-never option, the process never
terminates, thus nothing is ever written to the output file. Now the output is flushed after each event.
(Bug #24609402)
• Replication: A memory leak in mysqlbinlog was fixed. The leak happened when processing
fake rotate events, or when using --raw and the destination log file could not be created. The leak
only occurred when processing events from a remote server. Thanks to Laurynas Biveinis for his
contribution to fixing this bug. (Bug #24323288, Bug #82283)
• Replication: A slave server could lose events not yet applied when MASTER_AUTO_POSITION=0,
both replication threads were stopped, and the applier delay was changed using CHANGE MASTER
TO MASTER_DELAY=N. (Bug #23203678, Bug #81232)
References: See also: Bug #25340185, Bug #84375.
• Replication: Transmission of large GCS messages could take so long the sender appeared to have
died. (Bug #22671846)
• Replication: Multi-threaded slaves could not be configured with small queue sizes using
slave_pending_jobs_size_max if they ever needed to process transactions larger than that
size. Any packet larger than slave_pending_jobs_size_max was rejected with the error
ER_MTS_EVENT_BIGGER_PENDING_JOBS_SIZE_MAX, even if the packet was smaller than the
limit set by slave_max_allowed_packet.
With this fix, slave_pending_jobs_size_max becomes a soft limit rather than a hard
limit. If the size of a packet exceeds slave_pending_jobs_size_max but is less than
slave_max_allowed_packet, the transaction is held until all the slave workers have empty
queues, and then processed. All subsequent transactions are held until the large transaction has
been completed. The queue size for slave workers can therefore be limited while still allowing
occasional larger transactions. (Bug #21280753, Bug #77406)
• Replication: An incident event that broke replication was not written to the binary log with a
GTID, so that it was not possible to skip the event using SET gtid_next=value. Instead,
it was necessary to set the relay log file and relay log positions directly; this meant that, when
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MySQL 5.7 Release Notes
autopositioning was enabled, it was necessary first to disable it, then to set the relay log file and
position, and finally to re-enable autopositioning.
Now in such cases MySQL writes the incident event into the statement cache, so that a GTID is
generated and written for it prior to flushing, and that the slave applier works with the change. Then
users can skip the event using the SQL statement SET gtid_next=value, followed by BEGIN and
COMMIT. (Bug #19594845)
• Replication: In certain cases, the master could write to the binary log a last_committed value
which was smaller than it should have been. This could cause the slave to execute in parallel
transactions which should not have been, leading to inconsistencies or other errors. (Bug #84471,
Bug #25379659)
• Replication: When using group_replication_ip_whitelist=AUTOMATIC, IPs in the private
network are permitted automatically, but some class C IP addresses were not being permitted
correctly. (Bug #84329, Bug #25503458)
• Replication: When an existing GTID_NEXT transaction was assigned a conflicting GTID by the
server, Group Replication generated an assert upon detecting two transactions with same GTID.
This was because Group Replication generates the GTID after conflict detection, which is later than
with master/slave replication. The fix relaxes some conditions to only be called when commit is done
and a message has been added to alert you when a GTID has already been used. (Bug #84153, Bug
#25232042)
• Replication: The replication applier thread returns Error 3002 ER_INCONSISTENT_ERROR
when there is a difference between an expected error number and the actual error number. It is
now possible to ignore this error by using 3002 with slave_skip_errors. (Bug #83186, Bug
#24753281)
• Replication: MySQL lost its GTID position following a restart when a dump from mysqldump had
been used to load data.
To keep this problem from occurring, the mysql.gtid_executed table is now excluded
automatically from dumps made by mysqldump. (Bug #82848, Bug #24590891)
• Replication: Corruption of relay logs for one channel in multi-source replication caused good
channels not to be initalized during a server restart. In addition, when run with --skip-slavestart=false, the server also failed to start slave threads for those channels which were in good
condition, despite the fact that it should have started the slave threads for all good channels.
Now, regardless of any errors on other channels, the server attempts to create and initialize channels
that are in good condition, and starts slave threads for the good channels if --skip-slave-start
is disabled. As part of this fix, START SLAVE and STOP SLAVE, which are intended to operate on all
channels, are also modified such that they continue executing on all good channels even if they find
bad channels among them. (Bug #82209, Bug #24285104)
• Replication: The SQL thread was unable to GTID skip a partial transaction. (Bug #81119, Bug
#25800025)
• Debian client packages were missing information about conflicts with akonadi-backend-mysql
packages. (Bug #26002288)
• mysqldump could write database names in USE statements incorrectly. (Bug #25998635)
• If the mysql_stmt_close() C API function was called, it freed memory that later could be
accessed if mysql_stmt_error(), mysql_stmt_errno(), or mysql_stmt_sqlstate() was
called. To obtain error information after a call to mysql_stmt_close(), call mysql_error(),
mysql_errno(), or mysql_sqlstate() instead. (Bug #25988681)
• Queries could be cached incorrectly, leading to incorrect query results, under these circumstances:
InnoDB table; rows are being inserted but have not yet been committed; a query uses the table
9
MySQL 5.7 Release Notes
as a base table in a derived table; the optimizer chooses to materialize the derived table. (Bug
#25943038, Bug #86047)
• Man pages for a few utilities were missing from Debian/Ubuntu packages. (Bug #25811814)
• The field-t unit test failed to run with AddressSanitizer enabled. Thanks to Laurynas Biveinis for
the patch. (Bug #25803823, Bug #85678)
• Debian client packages were missing information about conflicts with native packages. (Bug
#25799475)
• The Perl path in #! lines at the beginning of Perl scripts has been adjusted to /usr/local/bin/
perl for FreeBSD 11. (Bug #25719975)
• For debug builds, the assertion added for Bug#59686 was too strict and could be raised when it
should not have been. (Bug #25685958)
References: See also: Bug #59686.
• A server exit occurred for downgrades to MySQL 5.7 from a MySQL 8.0 installation for which the
optimizer cost tables contained generated columns. (Bug #25650399)
• The server exited abnormally attempting to access invalid memory. (Bug #25501659)
• With mysqld secured by TCP wrappers and the hosts.allow and hosts.deny files configured
to restrict access from an IP address, connection attempts from that address resulted in too many
messages to the error log. (Bug #25476479, Bug #84708)
• mysqlpump no longer includes the slave_master_info and slave_relay_log_info tables
in dumps of the mysql system database. Restoring a dump file containing these tables caused
problems by changing the replication state improperly. (Bug #25469190)
• Changes made by calling mysql_options() to set MYSQL_OPT_SSL_MODE could be affected
by later mysql_options() calls. Now setting MYSQL_OPT_SSL_MODE is unaffected by later
mysql_options() calls. (Bug #25452210)
• A race condition could occur for CREATE TABLE statements with DATA DIRECTORY or INDEX
DIRECTORY clauses. (Bug #25451091)
• MySQL compilation in different directories produced different builds to leakage of absolute paths into
debug information and __FILE__. (Bug #25436469, Bug #84608)
• On SELinux in Enforcing mode, the keyring_okv plugin failed to connect to the Oracle Key Vault
server. (Bug #25420001)
• ALTER TABLE ... MODIFY on a DATETIME NOT NULL column using an AFTER clause resulted
in an ER_INVALID_USE_OF_NULL error. (Bug #25385334)
• The range optimizer could create an incorrect query tree, resulting in a server exit. (Bug #25369742,
Bug #25586531)
• mysqld_failed to start the server if the --datadir option was specified with a relative path
name. (Bug #25364806)
• XA PREPARE, XA ROLLBACK, and XA COMMIT for a transaction from a disconnected session did
not take a global commit lock and modified the binary log and InnoDB redo log even when FLUSH
TABLES WITH READ LOCK was in effect. This could lead to inconsistent backups when backup
tools assumed that the server was in a read-only state. (Bug #25364178, Bug #84442)
• GROUP_CONCAT(DISTINCT) returned nonunique values if the data size was greater than the value
of the tmp_table_size system variable. (Bug #25331425, Bug #84320)
• The fix for Bug #78777 had different effects depending on whether the Performance Schema is
enabled. (Bug #25309017, Bug #84305)
10
MySQL 5.7 Release Notes
References: This issue is a regression of: Bug #78777.
• An aggregate function in some nested queries could cause a server exit. (Bug #25303711)
• Virtual generated column expressions that used the CONV() or HEX() functions could cause
problems if the connection character set was changed. In this context, the table character set is now
used for these functions regardless of connection character set. (Bug #25287633)
• The Rewriter plugin did not perform locking properly if the read_only system variable was
enabled. (Bug #25264253)
• With read_only enabled, creation of non-TEMPORARY tables by non-SUPER users was permitted
under certain conditions. (Bug #25250768)
• For a table having a TIMESTAMP or DATETIME column having a default of CURRENT_TIMESTAMP,
the column could be initialized to 0000-00-00 00:00:00' if the table had a BEFORE INSERT
trigger. (Bug #25209512, Bug #84077)
• Certain stored functions, if used in a query WHERE clause, could be handled using Index Condition
Pushdown (which should not happen), resulting in a server exit. (Bug #25196653, Bug #25174454)
• Certain queries against InnoDB tables that used a primary key and a subquery could return incorrect
results if the index_merge_intersection flag of the optimizer_switch system variable was
enabled. (Bug #24829050, Bug #79675)
• Initialization of the keyring_okv plugin failed if the STANDBY_SERVER setting was missing from the
okvclient.ora configuration file, effectively making this a mandatory setting. STANDBY_SERVER is
now optional. (Bug #24816271)
• On x86 machines, the uint3korr() macro read 4 bytes of data instead of the intended 3 bytes.
(Bug #24807826, Bug #83264)
• An assertion was raised during a fetch operation by the memcached plugin. (Bug #24605783)
• Queries that contained UNION in a subquery and GROUP BY could return incorrect results. (Bug
#24595639)
• The server could dereference a null pointer when a deterministic function returning LONGTEXT was
used in a subquery. (Bug #24595581)
• Incorrect behavior could occur for INSERT statements executed in stored-program or preparedstatement context, if the VALUES part of an ON DUPLICATE KEY UPDATE clause referred to a
BLOB value in the INSERT column list. (Bug #24538207, Bug #25361251, Bug #25530880, Bug
#25684790)
• systemd support scripts in Debian packages contained hardcoded references to the data directory,
making it difficult to change the data directory using --datadir. (Bug #24398446, Bug #82417)
• MySQL failed to compile under macOS 10.10.5 using Clang. (Bug #24352163, Bug #82340)
• If a REPLACE statement tried to update a row in a table containing a virtual generated column of type
BLOB, subsequent DML statements could behave incorrectly. (Bug #23573575)
• The help output from mysqlxtest has been improved. (Bug #23107137, Bug #81086)
• Compiler flags were adjusted to eliminate numerous warnings that occurred when compiling the
keyring_file plugin using Clang. (Bug #22834591, Bug #80524)
• If enabling the Event Scheduler caused an event defined as ON COMPLETION NOT PRESERVE to
be dropped because its execution time had passed, the drop event was not written to the binary log,
causing slaves not to replicate it and replication failure if an event of the same name was created
later. (Bug #22150112)
11
MySQL 5.7 Release Notes
• LOAD XML INFILE performance became noticeably slower when the XML file being read contained
a great many spaces, such as those introduced by indenting or pretty-printing. Now all leading
whitespace is trimmed from each such value before reading it into memory. (Bug #16212207)
Changes in MySQL 5.7.18 (2017-04-10, General Availability)
• Compilation Notes
• Configuration Notes
• Deprecation and Removal Notes
• Packaging Notes
• Parser Notes
• Security Notes
• Thread Pool Notes
• X Plugin Notes
• Platform-Specific Notes
• Functionality Added or Changed
• Bugs Fixed
Compilation Notes
• Windows builds now use the default runtime libraries (builds use the /MD flag). (Bug #25611609)
• CMake support was added for compiling with Developer Studio 12.6. (Bug #25384295)
Configuration Notes
• MySQL failed to compile if -DENABLE_DEBUG_SYNC=OFF AND -DWITH_DEBUG=ON were both
given. The ENABLE_DEBUG_SYNC option has been removed and enabling WITH_DEBUG enables
Debug Sync. (Bug #18374703)
Deprecation and Removal Notes
• PROCEDURE ANALYSE() syntax is now deprecated and is removed in MySQL 8.0.
• The --temp-pool server option is deprecated and will be removed in MySQL 8.0.
• Support for DTrace is deprecated and is removed in MySQL 8.0.
Packaging Notes
• Microsoft Windows: Reminder: MySQL 5.7 requires the Microsoft Visual C++ 2013 Redistributable
Package to run on Windows platforms. Users should make sure the package has been installed on
the system before starting the server. The package is available at the Microsoft Download Center.
• Changes in RPM package structure require a larger set of packages to be removed to install MySQL
Server cleanly. (Bug #25603087)
• To avoid potential race conditions, Debian packages now use the GNU install utility rather than a
combination of mkdir, touch, and chown. (Bug #25258829)
• The my-default.cnf.sh file (used to produce a default my-default.cnf or my-default.ini
file) is no longer included in source distributions and my-default.cnf and my-default.ini are
no longer included in or installed by distribution packages. (Bug #22525354)
Parser Notes
12
MySQL 5.7 Release Notes
• The use of \N as a synonym for NULL in SQL statements is deprecated and is removed in MySQL
8.0. Use NULL instead.
This change does not affect text file import or export operations performed with LOAD DATA INFILE
or SELECT ... INTO OUTFILE, for which NULL continues to be represented by \N. See LOAD
DATA INFILE Syntax.
Security Notes
• Security Fix: The linked OpenSSL library for the MySQL Commercial Server has been updated to
version 1.0.2k. Issues fixed in the new OpenSSL version are described at http://www.openssl.org/
news/vulnerabilities.html.
This change does not affect the Oracle-produced MySQL Community build of MySQL Server,
which uses the yaSSL library instead. (Bug #25768671, Bug #25615451, CVE-2016-7055,
CVE-2017-3731, CVE-2017-3732)
• The keyring_okv plugin no longer supports RSA or DSA key types. (Bug #25540639)
• The keyring_okv keyring plugin now can use the SafeNet KeySecure Appliance as the KMIP back
end for keyring storage. For instructions, see Using the keyring_okv KMIP Plugin.
Thread Pool Notes
• To improve thread_pool plugin performance, connection authentication and initialization
have been moved from the acceptor thread to the thread pool worker threads that handle client
connections. This enables the acceptor thread to handle new connections at a higher rate with
reduced latency. The INFORMATION_SCHEMA TP_THREAD_GROUP_STATE table now contains
a CONNECT_THREAD_COUNT column that indicates the number of threads that are processing
or waiting to process connection initialization and authentication. There can be a maximum of
four connection threads per thread group; these threads expire after a period of inactivity. (Bug
#17159742)
X Plugin Notes
• The MYSQLX_TCP_PORT CMake option was ignored. (Bug #25493867, Bug #84804)
• The protobuf compiler emitted “unused import” warnings for mysqlx.proto. (Bug #25444009, Bug
#84641)
• Connections were released which were not initialized when validation occurred. (Bug #25392280)
• The Mysqlx_notice_warning_sent and Mysqlx_notice_other_sent status variable values
did not increment as expected. (Bug #25289949, Bug #84258, Bug #25290001, Bug #84260)
• The manual definition of the MYSQL_DYNAMIC_PLUGIN macro was redundant. (Bug #25162590,
Bug #83988)
• IPv6 connectivity support defined a new system variable Mysqlx-bind-address with the default
value of '0.0.0.0', but the default value should have been '*' so that connections to X Plugin may be
made using an IPv6 address, an IPv4 address, or a hostname. (Bug #25047909, Bug #83688)
• Sending Expect.Open to a connected socket before authentication led to the following error
messages:
... Plugin mysqlx reported: '10: Invalid message 24 received during client initialization'
... Plugin mysqlx reported: '10: ERROR reading from socket Bad file descriptor (9) 2'
(Bug #24940144, Bug #83494)
• On Linux, MySQL Shell in JavaScript and Python interactive mode hid collections if the letter case in
the collection name was not uniform. (Bug #24848125)
13
MySQL 5.7 Release Notes
• If multiple user accounts exist that match the authenticating user, the X Plugin would attempt to
authenticate all matching accounts instead of the best matching account. (Bug #24847537)
Platform-Specific Notes
• Solaris: The minimum required version of Solaris is now Solaris 11 update 3, due to a dependency
on system runtime libraries.
• Solaris: On Solaris, MySQL is now built with Developer Studio 12.5 instead of gcc. The binaries
require the Developer Studio C/C++ runtime libraries to be installed. See here for how to install only
the libraries:
https://docs.oracle.com/cd/E60778_01/html/E60743/gozsu.html
• Ubuntu 12.04 LTS: This is the last release in the MySQL 5.7 series to support Ubuntu 12.04 LTS. As
per the MySQL Support Lifecycle policy regarding ending support for OS versions that are obsolete
or have reached end of life, we plan to discontinue building binaries for the Linux distribution in future
releases. (Bug #25828475)
• Oracle Linux 5, Red Hat Enterprise Linux 5, and CentOS 5: This is the last release in the MySQL
5.7 series to support Oracle Linux 5, Red Hat Enterprise Linux 5, and CentOS 5. As per the MySQL
Support Lifecycle policy regarding ending support for OS versions that are obsolete or have reached
end of life, we plan to discontinue building binaries for those Linux distributions in future releases.
Moreover, we plan to build the generic Linux tarballs for the next release on Oracle Linux 6 using
glibc 2.12. (Bug #25828375)
Functionality Added or Changed
• Replication: View change events from a Group Replication group can now be replicated to an
external multithreaded slave (MTS) of type DATABASE. (Bug #25170698)
• Replication: When a negative or fractional timeout parameter was supplied to
WAIT_UNTIL_SQL_THREAD_AFTER_GTIDS(), the server behaved in unexpected ways. With this
fix:
• A fractional timeout value is read as-is, with no round-off.
• A negative timeout value is rejected with an error if the server is on a strict SQL mode; if the server
is not on a strict SQL mode, the value makes the function return NULL immediately without any
waiting and then issue a warning.
(Bug #24976304, Bug #83537)
• If MySQL was configured to build with the -Wno-error option, mysql_config produced incorrect
output for its --cflags option.
The set of compiler options that mysql_config and pkg-config produce now is determined by
whitelisting rather than blacklisting. (Bug #25040566, Bug #22898475, Bug #80662)
• The performance of UTF-8 binary collations was improved. (Bug #24788778, Bug #83247, Bug
#25076862)
• Consistency and maintainability of Debian/Ubuntu packaging maintainer scripts was improved. (Bug
#23588977)
• mysql_secure_installation is more strict about what it considers valid yes and no responses.
(Bug #13344753, Bug #62925)
• The replace utility is deprecated and will be removed in MySQL 8.0. If you wish to continue using
this utility, be sure to retain a copy from an installed version of MySQL.
Bugs Fixed
14
MySQL 5.7 Release Notes
• InnoDB: The restriction that required the first undo tablespace to use space ID 1 was removed.
The first undo tablespace may now be assigned a space ID other than 1. Space ID values for undo
tablespaces are still assigned in a consecutive sequence. (Bug #25551311)
• InnoDB: A DROP TABLE operation raised an assertion on a server with an
innodb_force_recovery setting of 5 or 6. DROP TABLE is no longer permitted with these
innodb_force_recovery settings. (Bug #25385590)
References: This issue is a regression of: Bug #19779113.
• InnoDB: Compiling the server without the Performance Schema caused a build failure. (Bug
#25348787)
• InnoDB: During read-ahead, the wrong page size was used to calculate the tablespace size. (Bug
#25330449)
• InnoDB: Compiling on Fedora 25 using DWITH_LZ4=system resulted in a build failure due to a
deprecated LZ4_COMPRESS_LIMITEDOUTPUT function. (Bug #25297593)
• InnoDB: Disabling macros such as UNIV_PFS_MUTEX, UNIV_PFS_RWLOCK, and
UNIV_PFS_THREAD caused compilation errors. (Bug #25251082)
• InnoDB: A NULL virtual column field name in a virtual index caused a server exit during a field name
comparison that occurs while populating virtual columns affected by a foreign key constraint. (Bug
#25222337)
• InnoDB: The file handle type name for InnoDB file I/O Performance Schema instrumentation was
changed from os_pfs_file_t to pfs_os_file_t. (Bug #25220118)
• InnoDB: During a range comparison, a secondary index field number was passed instead of
clustered index field number, eventually causing the retrieval of an incorrect field. (Bug #25175249)
• InnoDB: A server exit on restart was caused by missing my_thread_init() and
my_thread_exit() functions for background threads that initialize the st_my_thread_var
structure. (Bug #25167032)
• InnoDB: A memcached read operation with a non-default read batch size configuration resulted in a
server exit. (Bug #25147515)
• InnoDB: A gap lock was taken unnecessarily during foreign key validation while using the READ
COMMITTED isolation level. (Bug #25082593)
• InnoDB: After a TRUNCATE TABLE operation on a table with a FULLTEXT index, space size was
incorrectly calculated resulting in an invalid read. (Bug #25053705)
• InnoDB: During a checkpoint, all MLOG_FILE_NAME redo log records were written in a single minitransaction (mtr), causing a log parsing buffer overflow. (Bug #24793413, Bug #83245)
• InnoDB: A mechanism was added to debug builds to ensure that keys for InnoDB Performance
Schema instrumentation are registered with Performance Schema. The mechanism causes startup
to fail on debug builds if the number of Performance Schema keys does not match the number of
registered Performance Schema keys. (Bug #24686908)
• InnoDB: A race condition while updating table statistics could result in an estimated row count of 1
and an incorrect query execution plan. (Bug #24666839, Bug #82968)
• InnoDB: An error in code related to table statistics raised an assertion in the dict0stats.cc
source file. (Bug #24585978)
• InnoDB: A concurrent DML operation during an in in-place ALTER TABLE operation that rebuilt the
table did not update a virtual index, resulting in a mismatch between the virtual index and clustered
index. (Bug #23219499)
15
MySQL 5.7 Release Notes
• InnoDB: A TRUNCATE TABLE operation held the dict_sys mutex while scanning for and removing
pages from the buffer pool, causing concurrent DDL operations to stall. The mutex is now released
during the scan and acquired again when the scan is completed. (Bug #23070734, Bug #80060)
• InnoDB: SELECT COUNT(*) performance regressed in some cases due to a modification
introduced in MySQL 5.7.2 that caused InnoDB to count rows by traversing the clustered index
instead of a smaller secondary index. The modification was reverted. (Bug #23046302, Bug #80580)
• InnoDB: Inserting GIS data into an R-tree raised an assertion due to a missing page number field
that was encountered when storing the B-tree cursor. (Bug #23044098)
• InnoDB: Performance Schema instrumentation for InnoDB file I/O was disabled on Windows. (Bug
#14025581)
• InnoDB: The row_search_mvcc() function unnecessarily traversed the entire table for a range
query, which occurred when the record was not in the transaction read view. (Bug #84202, Bug
#23481444, Bug #25251375)
• Partitioning: Updating a row of a table that had partitioning on a generated column could raise an
assertion failure for debug builds, and return incorrect results in nondebug builds. (Bug #22574695,
Bug #80080)
• Replication: MEMBER_STATE of a group replication member did not go from ERROR to OFFLINE
when the STOP GROUP_REPLICATION command was executed if the error state was due to
ER3092. (Bug #25674926)
• Replication: With flow control enabled, reaching a minimum flow control quota of 1 causes
Group Replication to not stop throttling when the reason for throttling was no longer in effect. (Bug
#25461354)
• Replication: Using an unresolvable host name in group_replication_group_seeds
caused START GROUP_REPLICATION to fail. The fix ensures that host names in
group_replication_group_seeds are validated when starting Group Replication and the
list must contain at least one valid address. Invalid addresses are ignored. (Bug #25460324, Bug
#84674)
• Replication: The _gr_user account created by Group Replication plugin installation was not
reliably removed when the plugin was uninstalled. (Bug #25298987)
• Replication: When starting Group Replication on an offline node, the node could be configured for
replication, but fail for recovery. (Bug #25256910)
• Replication: When using a multi-threaded slave, applier errors displayed worker ID data that was
inconsistent with data externalized in Performance Schema replication tables. (Bug #25231367)
• Replication: Not all Group Replication GCS debug and trace messages were enabled in debug
mode. (Bug #25209109, Bug #84079)
• Replication: Compiling MySQL 5.7.17 failed with a variable length array error. (Bug #25163241, Bug
#83994)
• Replication: In row-based replication, a message that incorrectly displayed field lengths was
returned when replicating from a table with a utf8mb3 column to a table of the same definition
where the column was defined with a utf8mb4 character set. (Bug #25135304, Bug #83918)
• Replication: Group Replication GCS was not discarding messages when a member within the group
was inactive. (Bug #25134074)
• Replication: Some unnecessary warnings were given when the Group Replication plugin was
compiled on Windows platforms. (Bug #25119288)
• Replication: As assertion could be raised if the Group Replication plugin attempted to contact the
server when that was no longer possible. (Bug #25071492)
16
MySQL 5.7 Release Notes
• Replication: The GTID transaction skipping mechanism that silently skips a GTID transaction that
was previously executed did not work properly for XA transactions. (Bug #25041920)
• Replication: After executing restarts on the group replication applier SQL thread, the plugin could no
longer detect failure of the thread. (Bug #24969065)
• Replication: When the MTS slave applier stopped because of an (injected) error, it reported no
useful information for troubleshooting. (Bug #24822686)
• Replication: FLUSH BINARY LOGS could become slow with data replicated from many servers.
(Bug #24806259, Bug #83270)
• Replication: A partially failed CREATE USER, RENAME USER, or ALTER USER statement was not
correctly consuming an auto-generated or specified GTID when binary logging was disabled. (Bug
#24693798)
• Replication: Binlog_sender, which writes events from the binary log to a packet buffer and
then sends the packet to the slave, did not reduce the size of the send buffer as expected. (Bug
#24643036)
• Replication: When using a multi-threaded slave (slave_parallel_workers greater than 0) the
value of Seconds_Behind_Master was incorrect when rotating a relay log. (Bug #23532304)
• Replication: The server prevented several replication-related administrative statements from
working if the read_only system variable was enabled. (Bug #22857926)
• Replication: CHANGE MASTER TO for a channel that did not exist could raise an assertion. (Bug
#22255698)
• Replication: The delay specified by the binlog_group_commit_sync_delay system variable
was applied to too many binary log commit groups. (Bug #21420180)
• JSON: MySQL JSON source code built using with clang 3.9 raised undesired warnings. (Bug
#25039600)
• mysqldump failed to properly quote certain identifiers in SQL statements written to the dump output.
(Bug #25717383)
• Client preauthorization by the server was missing a length check for a length-encoded string. (Bug
#25714674)
• The (undocumented) WINDOWS_RUNTIME_MD CMake option has been removed. (Bug #25611359)
• mysqld_safe failed to restart the server if a PID_FILE.shutdown file was present. (Bug
#25572504)
References: This issue is a regression of: Bug #11751149.
• For Debian/Ubuntu packages, user-defined collation files could be overwritten during MySQL
upgrades. Charset files are now marked as conffiles so that user customizations generate a prompt
during upgrades whether to overwrite them. (Bug #25525628, Bug #84761)
• For CREATE TABLE statements that specified the table name with a database qualifier and included
a DATA DIRECTORY or INDEX DIRECTORY option, an error occurred if there was no default
database. (Bug #25514146, Bug #84861)
• Starting the server with performance_schema_digests_size=1 caused an abnormal exit. (Bug
#25492129, Bug #84786)
• MySQL failed to compile on some platforms with -DWITH_LIBWRAP=ON. CMake support now checks
whether tcpd.h has proper function prototypes. (Bug #25395543, Bug #84495)
• mysqld_safe did not check whether the directory named by the --basedir option existed. (Bug
#25365194)
17
MySQL 5.7 Release Notes
• Configuring CMake with -G ninja resulted in build output that was inappropriate for build platforms
other than Xcode or Visual Studio. (Bug #25358460)
• mysqld_safe failed if the error log file named by the --log-error option was a FIFO. (Bug
#25356221, Bug #84427)
• For prepared statements, an alias within a subquery or derived table might cause incorrect behavior
during statement execution if another alias depended on it. (Bug #25343335, Bug #84398, Bug
#25171608)
• mysqld_safe could fail if the --datadir option value ended with a / character. (Bug #25319457)
• A recent change to mysqld_safe caused the mysql.server script to be unable to start it if the
base directory was specified as an absolute path that differed from the compiled-in default absolute
path. (Bug #25319392, Bug #84263)
• The CONNECTION_CONTROL plugin failed to compile if the Performance Schema was disabled. (Bug
#25308357, Bug #84304)
• Passwords did not expire correctly for accounts created using MySQL Workbench. (Bug #25299309)
• For System V init scripts for RPMs, the [mysqld] option-file section was being ignored for some
options, such as pid-file. (Bug #25287707, Bug #84172)
• Init scripts failed to launch mysqld_safe if a non-default base directory was used. (Bug #25261472,
Bug #84219)
• CMake now detects whether a GCC 5.3.0 loop optimization bug occurs and attempts a workaround if
so. (Bug #25253540)
• mysqld_safe --no-defaults did not work (inadvertent consequence of an earlier bug fix). (Bug
#25244898, Bug #84173)
• Semicolon (;) characters within or between statements could cause distinct digests to be generated
from identical statements. (Bug #25244533, Bug #83253)
• For a client linked against libmysqlclient, invalid memory access could occur during use of
prepared statements. (Bug #25164932)
• The fix for Bug #25088048 caused the command used by mysqld_safe to start the MySQL server
to no longer include the mysqld path. (Bug #25144379)
References: This issue is a regression of: Bug #25088048.
• Executing a stored procedure containing a query that accessed a view could allocate memory that
was not freed until the session ended. (Bug #25053286)
• Compilation on FreeBSD 11 failed attempting to check MAP_NORESERVE, which is no longer defined.
(Bug #25048128, Bug #83689)
•
CMake support was added for compiling using the -std=c++03 option under Developer Studio 12.5.
This is now used rather than stlport by default. (Bug #24947136, Bug #83512, Bug #25229424)
• Privilege checking could be incorrect for a derived table used within a multiple-table UPDATE invoked
within a stored procedure or view object, for the second or subsequent execution of the object, if the
derived table was merged into the outer query. (Bug #24810564)
• Connections from a client to a server with SSL enabled succeeded even if --ssl-mode had a
value of VERIFY_CA or VERIFY_IDENTITY and the client did not provide a CA certificate. (Bug
#24732452, Bug #23189252, Bug #25397416, Bug #84508)
• If InnoDB statistics were incorrect, FOUND_ROWS() could return 1 even when the previous SELECT
returned no rows. (Bug #24714857, Bug #83110)
18
MySQL 5.7 Release Notes
• CMake now sets -DWITH_NUMA=ON for Debian platforms where possible. (Bug #24689101)
• A query could produce incorrect results if the WHERE clause contained a dependent subquery,
the table had a secondary index on the columns in the select list followed by the columns in the
subquery, and GROUP BY or DISTINCT permitted the query to use a Loose Index Scan. (Bug
#24671968, Bug #83005)
• The DebugPrintTest and DebugPrintDeathTest unit tests did not handle divide-by-zero testing
properly on the Aarch64 platform. Thanks to Alexey Kopytov for the patch. (Bug #24624555, Bug
#82889)
• Some account-management statements could incorrectly set the account password_lifetime
value to NULL. (Bug #24619222)
• Changes made to mysqld_safe in recent MySQL releases require the --ledir, --mysqld, -mysqld-version options to be specified on the command line; they can no longer be specified
in option files. This could cause failure of init scripts that invoke mysqld_safe. Such scripts now
pass the value of the MYSQLD_OPTS environment variable as the first command-line argument
to mysqld_safe, with the value set to such command line-only mysqld_safe option values as
may be required. On platforms that use systemd, the MYSQLD_OPTS value can be set in /etc/
sysconfig/mysqld with a line such as this:
MYSQLD_OPTS=" --ledir=/mysqld_ledir --mysqld=my_wrapper "
The value of MYSQLD_OPTS can also include mysqld options for mysqld_safe to pass to mysqld.
(Bug #24619033, Bug #82920)
References: This issue is a regression of: Bug #24464380, Bug #24483092, Bug #25088048, Bug
#25378439, Bug #25378565.
• For LOAD DATA used to insert data into an updateable view, the check to verify whether a column is
actually updatable was missing. (Bug #24595937)
• Queries of the form SELECT NULL IN (subquery) could raise an assertion due to a missing nullpointer check. (Bug #24595612)
References: This issue is a regression of: Bug #22090717.
• When populating the variables_by_thread table, the Performance Schema could attempt to
access session variables of other threads that were being deinitialized. (Bug #24555658)
• On Debian/Ubuntu platforms, the systemd startup script for MySQL ignored datadir settings in /
etc/mysql/my.cnf. (Bug #24517024, Bug #82709)
• For the null_audit plugin, setting the null_audit_event_record system variable improperly
could cause a server exit. This variable should be set only from within the null_audit plugin, so it
is now read only. (Bug #24493829, Bug #82670)
• A regular expression pattern match into a large string could result in a server exit due to memory
allocation failure or integer overflow. (Bug #24449076, Bug #24449090)
• An incorrect error was reported for CREATE TABLE statements with a large value for the
CONNECTION table option. The value is now limited to 1024 bytes. (Bug #24437124)
• For debug builds, if the binary log was enabled, executing the audit_log plugin
audit_log_filter_set_filter function could cause a server exit. (Bug #24437009)
• MySQL Enterprise Firewall did not record events if the audit_log plugin was installed. (Bug
#24413450, Bug #82473)
• EXPLAIN SELECT COUNT(*) FROM tbl_name could incorrectly report an Extra value of
Select tables optimized away due to a modification introduced in MySQL 5.7.2 that caused
19
MySQL 5.7 Release Notes
InnoDB to count rows by traversing the clustered index instead of a smaller secondary index. The
Extra value now displays Count Rows. (Bug #24337385, Bug #82313)
• mysqldumpslow failed to parse timestamps in the slow query log; it had not been updated to track a
change in log timestamp format. (Bug #24007040)
• Complete logical backups made with mysqlpump could not be restored if GTIDs were enabled.
To enable control over GTID information written to the dump file, mysqlpump now has a --setgtid-purged option that indicates whether to add a SET @@global.gtid_purged statement to
the output. (Bug #23748432)
• Messages written by the audit_log plugin to the error log regarding MYSQL_AUDIT_CONNECT
event failures now print the underlying error cause as well to aid debugging. (Bug #23710632)
• FORCE INDEX was ineffective for SELECT COUNT(*) queries. (Bug #23596760, Bug #81854)
• The audit_log plugin audit_log_filter_remove_filter() function caused a server exit if
given a NULL argument. (Bug #23522793)
• Grant tables with incorrect structure may cause problems in user management operations. As a
consequence of the fix for this, for any operation that modifies a grant table, the server now checks
whether the table has the expected structure and produces an error if not. mysql_upgrade must
be run to update the tables to the expected structure. (Bug #23295423, Bug #25095876, Bug
#25448037)
• Improper handling of a lock used by the version_tokens plugin and user-defined functions could
result in a server exit if a UDF was called while version_tokens was being uninstalled. (Bug
#23210850)
• The QUOTE() function could allocate excessive memory. A limit of max_allowed_packet bytes is
now imposed and returns NULL with a warning for attempts to allocate more. (Bug #23195404)
• When attempting to locate the data directory, mysqld_safe incorrectly considered
$MY_BASEDIR_VERSION/var as one of the possible locations. (Bug #23013510, Bug #80866)
• The main.log_tables-big test case could be unstable on highly loaded hosts. Thanks to
Laurynas Biveinis for the patch. (Bug #22874167, Bug #80607)
• The rpl.rpl_key_rotation test case did not synchronize properly with the master server.
Thanks to Laurynas Biveinis for the patch. (Bug #22838596, Bug #80531)
• Queries that used an aggregate function with DISTINCT could produce incorrect results. (Bug
#22686994, Bug #80310)
• For RPM packages, the default error-log location in the deployed /etc/my.cnf file differed from
the location in the installed logrotate script, causing logrotate to fail. (Bug #22322685)
• After performing inserts in a table containing an AUTO_INCREMENT column and then performing
a SELECT operation, the LAST_INSERT_ID() returns the correct value, but the value of the
mysql_insert_id() C API function was being reset to 0. (Bug #22028117, Bug #78778)
• With the use_index_extensions flag of the optimizer_switch system variable disabled, some
SELECT DISTINCT queries could return incorrect results. (Bug #21749123, Bug #78244)
• Debian packages were missing an AppArmor-related include file and incorrectly were marked
dependent on AppArmor (making it impossible to disable AppArmor by uninstalling it). (Bug
#20768958)
• In a replication environment, SET PASSWORD or ALTER USER could fail to execute on the slave due
to failure to parse the hash string correctly. (Bug #20228478)
• On non-Linux Unix systems, the mysql.server startup script used the Linux command pidof
rather than pgrep. (Bug #13788154, Bug #64342)
20
MySQL 5.7 Release Notes
• Starting multiple instances of mysqld_safe after an abnormal server exit could result in one
mysqld_safe instance killing another. As a consequence of the bug fix, the mysqld_safe.pid file
is no longer used. (Bug #11751149, Bug #41908)
• The --help message for mysqld_safe was corrected to mention that the --no-defaults, -defaults-file, and --defaults-extra-file options, if given, must be the first argument.
(Bug #11745176, Bug #11192)
• The bounds check for the XML parser position stack for each level (which has a fixed depth) used
the size of the array as the upper limit, and so was off by one. This is fixed by decreasing the
allowable depth by one, which actually matches the maximum number of elements in the position
stack. (Bug #83871, Bug #25111907)
References: See also: Bug #14040071, Bug #15948580.
• Timestamps for server-side prepared statements could be written to the binary log up to a second
behind timestamps for the corresponding nonprepared statements, leading to time value differences
between master and slave servers. (Bug #74550, Bug #19894382, Bug #25187670)
Changes in MySQL 5.7.17 (2016-12-12, General Availability)
• Compilation Notes
• MySQL Enterprise Notes
• Packaging Notes
• Security Notes
• Test Suite Notes
• X Plugin Notes
• Functionality Added or Changed
• Bugs Fixed
Compilation Notes
• For GCC versions higher than 4.4, -fno-expensive-optimizations was replaced with -ffpcontract=off, which has the effect of enabling more optimizations. Thanks to Alexey Kopytov for
the patch. (Bug #24571672, Bug #82760)
MySQL Enterprise Notes
• Enterprise Encryption for MySQL Enterprise Edition now enables server administrators to impose
limits on maximum key length by setting environment variables. These can be used to prevent clients
from using excessive CPU resources by passing very long key lengths to key-generation operations.
For more information, see Enterprise Encryption Usage and Examples. (Bug #19687742)
Packaging Notes
• RPM packages now are built with -DWITH_NUMA=ON for platforms with NUMA support: OEL higher
than EL5, Fedora, SLES, Docker. (Bug #24689078)
Security Notes
• Security Fix: OpenSSL is ending support for version 1.0.1 in December 2016; see https://
www.openssl.org/policies/releasestrat.html. Consequently, MySQL Commercial Server builds
now use version 1.0.2 rather than version 1.0.1, and the linked OpenSSL library for the MySQL
Commercial Server has been updated from version 1.0.1 to version 1.0.2j. For a description of issues
fixed in this version, see https://www.openssl.org/news/vulnerabilities.html.
21
MySQL 5.7 Release Notes
This change does not affect the Oracle-produced MySQL Community build of MySQL Server, which
uses the yaSSL library instead.
• Incompatible Change: These changes were made to mysqld_safe:
• Unsafe use of rm and chown in mysqld_safe could result in privilege escalation. chown now
can be used only when the target directory is /var/log. An incompatible change is that if the
directory for the Unix socket file is missing, it is no longer created; instead, an error occurs. Due to
these changes, /bin/bash is required to run mysqld_safe on Solaris. /bin/sh is still used on
other Unix/Linux platforms.
• The --ledir option now is accepted only on the command line, not in option files.
• mysqld_safe ignores the current working directory.
Other related changes:
• Initialization scripts that invoke mysqld_safe pass --basedir explicitly.
• Initialization scripts create the error log file only if the base directory is /var/log or /var/lib.
• Unused systemd files for SLES were removed.
(Bug #24483092, Bug #25088048, Bug #25378439, Bug #25378565)
References: See also: Bug #24464380, Bug #24388753, Bug #24619033, Bug #82920.
• MySQL Server now includes a plugin library that enables administrators to introduce an increasing
delay in server response to clients after a certain number of consecutive failed connection attempts.
This capability provides a deterrent that slows down brute force attacks that attempt to access
MySQL user accounts. For more information, see The Connection-Control Plugins.
Test Suite Notes
• mysql-test-run.pl could not be run with --valgrind-option=--tool=custom_tool, for values of
custom_tool such as massif or helgrind, because it added the options for memcheck that
might not be understood by other tools. Also, the mysql-test-run.pl --callgrind option did
not work because it supplied an invalid --base option to callgrind. Thanks to Daniel Black for the
patch on which the fixes were based. (Bug #23713613, Bug #82039)
X Plugin Notes
• A failure occurred when X Plugin called a hostname resolution function. (Bug #25652096, Bug
#85154)
• The stmt field was marked as required in the message:
message Mysqlx.Crud.ModifyView {
required Collection collection = 1;
optional
optional
optional
optional
string definer = 2;
ViewAlgorithm algorithm = 3;
ViewSqlSecurity security = 4;
ViewCheckOption check = 5;
repeated string column = 6;
required Mysqlx.Crud.Find stmt = 7;
}
(Bug #24968735, Bug #83595)
• For a table created with CREATE TABLE foo (doc JSON), the statement list_objects
incorrectly reported the table as a collection. (Bug #24963952)
22
MySQL 5.7 Release Notes
• When two X Plugin instances were started on the same port, the resulting error message was split
over two lines and contained duplicate information. (Bug #24679018, Bug #83008)
• The performance_schema.threads table did not show processlist statistics for the X Plugin.
(Bug #24638038)
• If the client sent an unknown message type to the server, the server would send back an error
message and then disconnect the client. (Bug #24611754, Bug #82868)
• When the client sent a zero length message, the X Plugin did not send a response. For a subsequent
message the client received an error E_X_BAD_MESSAGE and was disconnected, depending on the
header content. (Bug #24595459, Bug #82862)
• X Plugin displayed its version to any connected user, including those not authenticated. (Bug
#24562707, Bug #82784)
• When X Plugin failed to bind to @@global.mysqlx_port it did not indicate this failure in the global
status variables. (Bug #24554351, Bug #82761)
• The statement list_objects returned incorrect information for some views in sys database. (Bug
#24472325)
• X Plugin was trying to send result sets to a client, even where the connection had been closed. The
plugin now stops execution of a stored procedure if the connection is reset. (Bug #24440344)
Functionality Added or Changed
• Incompatible Change; Partitioning: The generic partitioning handler in the MySQL server is
deprecated, and will be removed in MySQL 8.0. As part of this change, the mysqld --partition
and --skip-partition options as well as the -DWITH_PARTITION_STORAGE_ENGINE build
option are also deprecated, and will later be removed; partitioning will no longer be shown in the
INFORMATION_SCHEMA.PLUGINS table or in the output of SHOW PLUGINS.
Following the removal of the generic partitioning handler, the storage engine used for a given table
will be expected to provide its own (“native”) partitioning handler as the InnoDB and NDB storage
engines currently do. Currently, no other MySQL storage engines provide native partitioning support,
nor is any planned for any other storage engines in current or development versions of MySQL.
Use of tables with nonnative partitioning now results in an ER_WARN_DEPRECATED_SYNTAX
warning. Also, the server performs a check at startup to identify tables that use nonnative
partitioning; for any found, the server writes a message to its error log. To disable this check, use the
--disable-partition-engine-check option.
To prepare for migration to MySQL 8.0, any table with nonnative partitioning should be changed to
use an engine that provides native partitioning, or be made nonpartitioned. For example, to change a
table to InnoDB, execute this statement:
ALTER TABLE table_name ENGINE = INNODB;
• InnoDB: By default, InnoDB reads uncommitted data when calculating statistics. In the case of
an uncommitted transaction that deletes rows from a table, InnoDB excludes records that are
delete-marked when calculating row estimates and index statistics, which can lead to non-optimal
execution plans for other transactions that are operating on the table concurrently using a transaction
isolation level other than READ UNCOMMITTED. To avoid this scenario, a new configuration option,
innodb_stats_include_delete_marked, can be enabled to ensure that InnoDB includes
delete-marked records when calculating persistent optimizer statistics. (Bug #23333990)
• The systemd service file for mysqld now includes a Documentation value in the [Unit] section
to provide a link to the systemd documentation in the MySQL Reference Manual. (Bug #24735762)
• Unit testing now uses Google Mock 1.8. (Bug #24572381, Bug #82823)
23
MySQL 5.7 Release Notes
• If mysqld is invoked with --daemonize, stdout and stderr are redirected to /dev/null
if connected to a terminal type device, so that mysqld can behave as a true daemon. (Bug
#21627629)
• MySQL Group Replication is a new MySQL plugin that enables you to create a highly available
distributed MySQL service across a group of MySQL server instances, with data consistency, conflict
detection and resolution, and group membership services all built-in. By using a powerful new
group communication service, which provides an implementation of the popular Paxos algorithm,
the group of MySQL Server instances automatically coordinates on data replication, consistency,
and membership. This provides all of the built-in mechanisms necessary for making your MySQL
databases highly available.
By default Group Replication operates in single-primary mode where a single server instance,
called the primary, accepts write requests. The remaining server instances in the group, called
secondaries, function as replicas of the primary. In the event of an unexpected failure of the primary,
an automatic primary election process takes place and one of the secondaries is elected as the
new primary. Group Replication also supports virtually synchronous multi-primary replication, with
certain considerations and restrictions, which offers update everywhere functionality. In this mode all
members are equal and you can distribute your reads and writes across all MySQL Server instances
in the group.
Regardless of the operating mode, Group Replication provides a dynamic membership service that
relies on distributed failure detection. Server instances can join and leave the group dynamically,
and you can query the group's membership list at any point through Performance Schema tables.
Server instances that join the group automatically synchronize their state with the group by doing an
automatic point-in-time recovery which ensures that they reach synchrony with the group.
MySQL Group Replication's virtually synchronous replication is also a fully integrated part of MySQL,
using the InnoDB storage engine, the Performance Schema tables, standard GTIDs and the well
known replication infrastructure (binary and relay logs, multi-source replication, multi-threaded
slave execution, etc.), which makes it a familiar and intuitive experience for existing MySQL users
and makes it very easy to integrate with MySQL's standard asynchronous and semisynchronous
replication, allowing you to mix and match as needed to create varied and complex replication
topologies.
Bugs Fixed
• Incompatible Change: A change made in MySQL 5.7.8 for handling of multibyte character sets by
LOAD DATA was reverted due to the replication incompatibility (Bug #24487120, Bug #82641)
References: See also: Bug #23080148.
• NDB Cluster: MySQL NDB Cluster encountered race conditions compiling lex_hash.h. (Bug
#24931655, Bug #83477)
• InnoDB; Microsoft Windows: On a MySQL 64-bit build on Windows, a file I/O retry result was
misinterpreted due to a missing cast necessary for the correct operation of the retry path, resulting in
a failing assertion and operating system error. (Bug #24711351)
• InnoDB: The INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS table reported NULL for
a foreign key constraint name (UNIQUE_CONSTRAINT_NAME) after restarting the server. (Bug
#25126722)
• InnoDB: A prepared XA transaction was rolled back by a high priority transaction. The high priority
transaction should wait if the blocking transaction is in a prepared state. (Bug #25032066)
• InnoDB: InnoDB passed an invalid argument to syscall(SYS_futex). (Bug #24923840, Bug
#83375)
• InnoDB: The GCC mach_parse_compressed function should load one to five bytes depending
on the value of the first byte. Due to a GCC bug, GCC 5 and 6 emit code to load four bytes before
24
MySQL 5.7 Release Notes
the first byte value is checked (GCC Bug #77673). A workaround prevents this behavior. Thanks to
Laurynas Biveinis for the patch. (Bug #24707869, Bug #83073)
• InnoDB: Due to a glibc bug, short-lived detached threads could exit before the caller had returned
from pthread_create(), causing a server exit. Thanks to Laurynas Biveinis for the patch. (Bug
#24605956, Bug #82886)
• InnoDB: After increasing the value of innodb_undo_logs and restarting the server, the number
of active undo tablespaces was not increased when assigning undo tablespaces to newly allocated
rollback segments. (Bug #24488141)
• InnoDB: InnoDB incorrectly reported an error about missing encryption when restoring pages from
the doublewrite buffer during recovery. (Bug #24471076)
• InnoDB: A cached undo segment was not removed from the rollback segment history during a slow
shutdown. (Bug #24450908)
• InnoDB: An error during a table-rebuilding operation on a table with only a generated clustered index
(GEN_CLUST_INDEX) raised and assertion due to an error called with an invalid key name. (Bug
#24444831)
• InnoDB: Rotating the tablespace encryption master key while the server is in read-only mode raised
an assertion instead of displaying an error message. (Bug #24404091)
• InnoDB: On a table without an explicitly defined primary key, InnoDB did not replace the implicit
clustered index (GEN_CLUST_INDEX) when a unique key was defined on a NOT NULL column. (Bug
#24397406)
• InnoDB: A high priority transaction involving a foreign key constraint check was not able to kill a
lower priority blocking transaction. (Bug #24347476)
• InnoDB: Page cleaner threads asserted due to a regression related to the adaptive hash index
feature. (Bug #24346574)
References: This issue is a regression of: Bug #21407023.
• InnoDB: InnoDB failed to free memory used by the full-text optimizer thread. (Bug #24331265)
• InnoDB: When adding a new index, the server dropped an internally defined foreign key index and
attempted to use a secondary index defined on a virtual generated column as the foreign key index,
causing a server exit. InnoDB now permits a foreign key constraint to reference a secondary index
defined on a virtual generated column. (Bug #23533396)
• InnoDB: An INFORMATION_SCHEMA.FILES query resulted in a server exit due to a race condition
with a concurrent tablespace creation operation. (Bug #23477214)
• InnoDB: A table-copying online ALTER TABLE operation on a ROW_FORMAT=REDUNDANT table with
indexed virtual columns raised an assertion. (Bug #22018745)
• InnoDB: SHOW ENGINE INNODB STATUS output showed a “cleaning up” state for an idle thread.
Thread state information was not reset after statement execution. (Bug #21974225, Bug #78777)
• InnoDB: After a server restart, concurrent INSERT operations a table with an auto-increment primary
key resulted in a duplicate entry error. The current auto-increment value was not changed after
auto_increment_increment and auto_increment_offset settings were modified. (Bug
#20989615, Bug #76872)
• Replication: When using XA transactions, if a lock wait timeout or deadlock occurred for the applier
(SQL) thread on a replication slave, the automatic retry did not work. The cause was that while the
SQL thread would do a rollback, it would not roll the XA transaction back. This meant that when the
transaction was retried, the first event was XA START which was invalid as the XA transaction was
already in progress, leading to an XAER_RMFAIL error. (Bug #24764800)
25
MySQL 5.7 Release Notes
References: See also: Bug #83588, Bug #24923091, Bug #24966941.
• Replication: The group commit update of GTIDs has been refactored to improve performance on
workloads with many small transactions. (Bug #24398760)
• Replication: If the relay_log option was not specified in a configuration file, the
relay_log_basename variable was being internally constructed on the fly using hostname but the
relay_log_basename variable was not set. When a slave tried to access this uninitialized variable
it resulted in an unexpected halt of the server. (Bug #24352667)
• Replication: For servers built with yaSSL, using group replication with encrypted connections could
result in timeout failures waiting for view delivery. (Bug #23592214)
• Replication: Tables with special DEFAULT columns, such as DEFAULT CURRENT_TIMESTAMP,
that existed only on a slave were not being updated when using row-based replication
(binlog_format=ROW). (Bug #22916743)
• Replication: An XA PREPARE statement that failed during the intermediate steps could lead to an
inconsistent XA transaction state, where ID = -1 but the binlogged flag was set to true. This
caused asserts while executing XA COMMIT and XA ROLLBACK queries. (Bug #22915670)
• Replication: Enabling semisynchronous replication when a server was during the commit stage
could cause the master to stop unexpectedly. This was related to the patch for Bug# 75570. (Bug
#22202516)
• Replication: The number of generated unwanted fseeks into the binary log file being replicated to a
slave has been reduced. (Bug #83226, Bug #24763579)
• Replication: The fix for Bug #81657 was not correctly merged into MySQL 5.7. Thanks to Laurynas
Biveinis for alerting us. (Bug #83124, Bug #24715790)
• Replication: The rpl.rpl_binlog_errors test was failing sporadically on Windows. (Bug
#82302, Bug #24330138)
• Replication: When binlog_group_commit_sync_delay was set to a value
between 1 and 9, if binlog_group_commit_sync_no_delay_count was set
to a value greater than 1, and the number of transaction commits was less than
binlog_group_commit_sync_no_delay_count, these commits hung forever if no more
commits were received; and if binlog_group_commit_sync_no_delay_count was set to 0, all
transaction commits hung forever. (Bug #80652, Bug #22891628)
• Replication: When starting semisynchronous replication, if more than 1024 file descriptors existed,
the semisynchronous socket was not created correctly. This prevented semisynchronous replication
from functioning correctly. (Bug #79865, Bug #23581389)
• JSON: When a JSON value consisted of a large sub-document wrapped in many levels of JSON
arrays, objects, or both, serialization of the JSON value sometimes required an excessive amount
time to complete. (Bug #23031146)
• Some Linux startup scripts did not process the datadir setting correctly. (Bug #25159791)
• CREATE TABLE now requires the FILE privilege if DATA DIRECTORY or INDEX DIRECTORY is
specified explicitly as a table or partition option. ALTER TABLE requires the FILE privilege if either
option is specified explicitly as a partition option (it ignores them if specified as table options). (Bug
#25092566)
• CMake now avoids configuring the -fexpensive-optimizations option for GCC versions for
which the option triggers faulty shift-or optimizations. (Bug #24947597, Bug #83517)
• OEL RPM packages now better detect which platforms have multilib support (for which 32-bit and
64-bit libraries can be installed). Thanks to Alexey Kopytov for the patch. (Bug #24925181, Bug
#83457)
26
MySQL 5.7 Release Notes
• OEL RPM packages now better detect which platforms do not have multilib support (for which 32-bit
and 64-bit libraries can be installed). Thanks to Alexey Kopytov for the patch. (Bug #24916428, Bug
#83428)
• Information about building MySQL 5.6 compatibility libraries in the MySQL 5.7 and higher .spec
file is needed only for building libmysqlclient and libmysqld. Information about building the
InnoDB memcached plugin was removed. (Bug #24908345, Bug #83409)
• To better provide atomic file creation, Debian packaging scripts now use the coreutils install
command rather than touch, chmod, and chown. (Bug #24688682)
• For SLES packages, a typo in the installation script postamble prevented some cleanup from
occurring. (Bug #24605300, Bug #82389)
• Warnings occurring during CREATE TABLE ... SELECT could cause a server exit. (Bug
#24595992)
• For LOAD DATA statements, input data with too many column values produced only a warning,
rather than an error as in MySQL 5.6. An error now occurs. (Bug #24577194, Bug #82830)
• For segmentation faults on FreeBSD, the server did not generate a stack trace. (Bug #24566529,
Bug #23575445, Bug #81827)
• The .mylogin.cnf option file is intended for use by client programs, but the server was reading it
as well. The server no longer reads it. (Bug #24557925)
• The X Plugin was built with compilation options different from other plugins. (Bug #24555770, Bug
#82777)
• If mysqladmin shutdown encountered an error determining the server process ID file, it displayed
an error message that did not clearly indicate the error was nonfatal. It now indicates that execution
continues. (Bug #24496214)
• The data structure used for ZEROFILL columns could experience memory corruption, leading
eventually to a server exit. (Bug #24489302)
• Operation of the mysql-multi.server.sh script was based on my.cnf in the data directory. That
option file is no longer used, so mysql-multi.server.sh has been removed. (Bug #24487870)
• Use of very long subpartition names could result in a server exit. Now partition or subpartition names
larger than 64 characters produce an ER_TOO_LONG_IDENT error. (Bug #24400628, Bug #82429)
• The Gis_wkb_vector<Gis_point> copy constructor was not explicitly instantiated, causing build
problems for the Intel compiler. (Bug #24397833, Bug #82358)
• Upgrading from MySQL 5.6 to 5.7.13 and then to 5.7.14 resulted in an incorrect column order in the
mysql.slave_master_info system table. (Bug #24384561, Bug #82384)
• The AppArmor profile installed by Ubuntu packages was missing an entry permitting libnuma to
read a /sys hierarchy path, resulting in server startup failure. (Bug #23854929)
• For an INSERT statement for which the VALUES list produced values for the second or later
row using a subquery containing a join, the server could exit after failing to resolve the required
privileges. (Bug #23762382)
• Infinite recursion could occur if the audit_log plugin signalled an error while handling an error.
(Bug #23717558, Bug #82052)
• MySQL now uses readdir() rather than readdir_r(). The latter has been deprecated since
glibc 2.24 and caused debug builds of MySQL and builds using GCC 6.1 to fail.
Additionally, several problems resulting in GCC 6.1 compiler warnings were corrected. (Bug
#23708395, Bug #24437737, Bug #82515, Bug #24459890, Bug #25103242)
27
MySQL 5.7 Release Notes
• For audit log events in the connection class, the connection_type value was available only for
connect events. The value is now available in connect, disconnect, and change-user events. (Bug
#23541550)
• On Solaris, gettimeofday() could return an invalid value and cause a server shutdown. (Bug
#23499695)
• The keyring_file plugin could attempt to write keys to its storage file when the file did not exist.
To ensure that keys are flushed only when the correct storage file exists, keyring_file now stores
a SHA-256 checksum of the keyring in the file. Before updating the file, the plugin verifies that it
contains the expected checksum. (Bug #23498254)
• START GROUP REPLICATION uses stacked Srv_session and did not return to the correct thread.
START GROUP REPLICATION and STOP GROUP REPLICATION are now removed from the list of
permitted commands. (Bug #23337984)
• A union query resulting in tuples larger than max_join_size could result in a server exit. (Bug
#23303485)
• For debug builds, failure to prepare a branch of an XA transaction could lead to a server exit. (Bug
#23264552, Bug #81375)
• The optimizer could choose ref access on a secondary index rather than range access on the
primary key, even when the cost was higher. (Bug #23259872, Bug #81341)
• For a query with ORDER BY and LIMIT, an optimizer trace did not record the optimizer's switch to a
different index. (Bug #23227428, Bug #81250)
• For some deeply nested expressions, the optimizer failed to detect stack overflow, resulting in a
server exit. (Bug #23135667)
• The sys schema ps_truncate_all_tables() function did not work with read_only enabled
or for users with the SUPER privilege with super_read_only enabled, due to errors attempting to
truncate Performance Schema tables. The server now skips the read_only/super_read_only
check for Performance Schema tables, with the result that ps_truncate_all_tables() will work
under such configurations. (Bug #23103937, Bug #81009)
• For sessions created through the X Plugin, incorrect thread attachment/detachment could cause a
server exit. (Bug #23057045)
• The OS X DMG installer did not properly set up keyring plugin installation. (Bug #22991650)
• A binary (in-place) upgrade from MySQL 5.6 to 5.7 followed by a data export performed using
mysqlpump resulted in an Invalid default value for date_column error for attempts to
reload the dump file. (Bug #22919028, Bug #80706)
• SQL statements executed through the X Plugin were not instrumented in the Performance Schema.
(Bug #22859462)
• DROP INDEX operations could fail due to inconsistent handling of index prefix lengths for TEXT-type
columns (TINYTEXT and so forth). (Bug #22740093, Bug #80392)
• The innodb_numa_interleave system variable was erroneously available on some systems that
were not NUMA-enabled. Thanks to Tomislav Plavcic for the patch.
CMake now sets the default WITH_NUMA value based on whether the current platform has NUMA
support. For platforms without NUMA support, CMake behaves as follows:
• With no NUMA option (the normal case), CMake continues normally, producing only this warning:
NUMA library missing or required version not available
• With -DWITH_NUMA=ON, CMake aborts with this error: NUMA library missing or required version
not available
28
MySQL 5.7 Release Notes
(Bug #22678436, Bug #80288)
• When taking the server offline, a race condition within the Performance Schema could lead to a
server exit. (Bug #22551677)
• On macOS, if a table with an associated trigger was renamed to a new name containing
both lowercase and uppercase characters, DROP TRIGGER for the trigger resulted in an
ER_NO_SUCH_TABLE error for the table. (Bug #22512899, Bug #79873)
• In the MYSQL_FIELD C API structure, the org_table value for derived tables was *, which could
cause failure for queries that depend on this value. The org_table value for views and derived
tables now is set as follows: If the column is selected from a view, org_table names the view. If the
column is selected from a derived table, org_table names the base table. If a derived table wraps
a view, org_table still names the base table. If the column is an expression, org_table is the
empty string. (Bug #22364401, Bug #79641)
• The Performance Schema events_statements_summary_by_digest table could contain
multiple rows for the same statement digest and schema combination, rather than the expected
single (unique) row. (Bug #22320066, Bug #79533)
• For Performance Schema system and status variable tables, variable values expressed in a
character set different from utf8 could be truncated or incorrect. (Bug #22313205)
• Queries that were grouped on a column of a BLOB-based type, and that were ordered on the result of
the AVG(), VAR_POP(), or STDDEV_POP() aggregate function, returned results in the wrong order if
InnoDB temporary tables were used. (Bug #22275357, Bug #79366)
• On Ubuntu, error messages were displayed during upgrades from Community to Commercial
packages that made it appear as though mysqld and my_print_defaults had not been installed.
Those messages were spurious and have been silenced. (Bug #21807248)
• An invalid string value in the WHERE clause of an UPDATE statement, caused an index scan rather
than a range scan to be used. For values not present in the index, this could be much slower. Now
the optimizer determines this to be an “impossible WHERE” condition. (Bug #21032418, Bug #76933)
• The return value from an fread() call was not checked. (Bug #20671150)
• An in-place ALTER TABLE operation failed to report an error when adding a DATE or DATETIME
column under these conditions: a) the column was NOT NULL and no default value was supplied; b)
strict and NO_ZERO_DATE SQL modes were enabled; c) the table was not empty.
An ALTER TABLE operation failed with an error rather than a warning when adding a DATE or
DATETIME column under these conditions: a) the column was NOT NULL and no default value was
supplied; b) strict SQL mode was enabled and NO_ZERO_DATE SQL mode was not enabled; c) the
table was not empty. (Bug #16888677)
Changes in MySQL 5.7.16 (2016-10-12, General Availability)
• Deprecation and Removal Notes
• Security Notes
• X Plugin Notes
Deprecation and Removal Notes
• With the introduction of the data dictionary in MySQL 8.0, the --ignore-db-dir option and
ignore_db_dirs system variable became superfluous and were removed in that version.
Consequently, they are now deprecated in MySQL 5.7.
Security Notes
29
MySQL 5.7 Release Notes
• Security Fix: The linked OpenSSL library for the MySQL Commercial Server has been updated to
version 1.0.1u. For a description of issues fixed in this version, see http://www.openssl.org/news/
vulnerabilities.html.
This change does not affect the Oracle-produced MySQL Community build of MySQL Server, which
uses the yaSSL library instead. (Bug #24753389)
• Incompatible Change: For STANDALONE and WIN builds, the default secure_file_priv
value has changed from the empty string to NULL. This is a secure-by-default setting because it
disables import and export operations. To permit those operations, set secure_file_priv to
the path name of the directory to use for those operations. (Bug #24679907, Bug #24695274, Bug
#24707666)
• yaSSL was upgraded to version 2.4.2. This upgrade corrects issues with: Potential AES side channel
leaks; DSA padding for unusual sizes; the SSL_CTX_load_verify_locations() OpenSSL
compatibility function failing to handle long path directory names. (Bug #24512715, Bug #24740291)
X Plugin Notes
• Boost classes with corresponding functionality in C++ 11 were moved or wrapped. (Bug #24680856)
• X Plugin generated an incorrect query when a duplicate field name existed in an Update statement.
(Bug #24510083)
Changes in MySQL 5.7.15 (2016-09-06, General Availability)
• Security Notes
• Test Suite Notes
• Functionality Added or Changed
• Bugs Fixed
Security Notes
• The validate_password plugin now supports the capability of rejecting passwords that match
the current session user name, either forward or in reverse. To enable control over this capability,
the plugin exposes a validate_password_check_user_name system variable. By default, this
variable is disabled; the default will change to enabled in MySQL 8.0. For more information, see
Password Validation Plugin Options and Variables.
Test Suite Notes
• In mysql-test-run.pl, a limit of 50 was imposed on the number of workers for parallel testing,
which on systems with more than 50 CPUs resulted in exhaustion of unique thread IDs. The IDexhaustion problem has been corrected, and the limit of 50 on number of workers has been lifted.
Thanks to Daniel Black for the patch on which this change was based. Additionally, these changes
were made:
• To avoid idle workers, the number of parallel workers now is limited to the number of tests.
• Previously, if --parallel=auto was given and the MTR_MAX_PARALLEL environment variable
was not set, a limit of 8 was imposed on the number of parallel workers. This limit has been lifted.
(Bug #22342399, Bug #79585)
Functionality Added or Changed
• InnoDB: A new dynamic configuration option, innodb_deadlock_detect, can be used to disable
deadlock detection. On high concurrency systems, deadlock detection can cause a slowdown when
30
MySQL 5.7 Release Notes
numerous threads wait for the same lock. At times, it may be more efficient to disable deadlock
detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a
deadlock occurs. (Bug #23477773)
• The systemd support script for the unit file (mysqld_pre_systemd) now assists in creating the
error log file only if its location matches the pattern /var/log/mysql*.log. In other cases, the error log
directory must be writable or the error log must be present and writable for the user running the
mysqld process. Also, mysqld_pre_systemd now avoids creating insecure temporary files. (Bug
#24516262)
• The CMake WITH_LZ4 option has been added to control which LZ4 library is used during
compilation. By default WITH_LZ4 is set to bundled, so the library provided with MySQL is used.
Setting WITH_LZ4 to system uses the LZ4 library from the operating system. (Bug #23607230)
Bugs Fixed
• InnoDB: An ALTER TABLE ... ENCRYPTION='Y', ALGORITHM=COPY operation on a table
residing in the system tablespace raised an assertion. (Bug #24381804)
• InnoDB: Creating an encrypted table on a Fusion-io disk with an innodb_flush_method setting of
O_DIRECT caused a fatal error. (Bug #24329079, Bug #82073)
• InnoDB: An operation that dropped and created a full-text search table raised an assertion. (Bug
#24315031)
• InnoDB: Accessing full-text search auxiliary tables while dropping the indexed table raised an
assertion. (Bug #24009272)
• InnoDB: An online DDL operation on a table with indexed BLOB columns raised an assertion during
logging of table modifications. (Bug #23760086)
• InnoDB: In some cases, code that locates a buffer pool chunk corresponding to given pointer
returned the wrong chunk. Thanks to Alexey Kopytov for the patch. (Bug #23631471, Bug #79378)
• Replication: The addition of the transaction-write-set-extraction=XXH64 option uses
xxHash symbols from liblz4. Although the xxHash symbols are exported by liblz4, the header file is
not part of the API, so compilation failed when building with WITH_LZ4=system. The fix ensures
that xxHash is built separately from liblz4 so that it is available both when using the system and
bundled LZ4 libraries. (Bug #82426, Bug #24399819)
References: See also: Bug #23607230.
• Replication: mysqlbinlog --read-from-remote-server log1 log2 was opening a new
connection for log2 without freeing the connection used for log1. Thanks to Laurynas Biveinis for
the contribution. (Bug #81675, Bug #23540182)
• Replication: The MTR binary log test suite failed to clean up copied files. Thanks to Daniel Black for
the contribution. (Bug #80881, Bug #23016254)
• Replication: With binlog_row_image=FULL, when updating single tables temporary tables were
unnecessarily being used. The fix ensures single table update follows the same pattern as multi-table
update. (Bug #79867, Bug #22510353)
• Solaris: The client library failed to build on Solaris using the Cstd library. (Bug #24353920, Bug
#82347)
• mysqld_safe attempted to read my.cnf in the data directory, although that is no longer a standard
option file location. (Bug #24482156)
• For mysqld_safe, the argument to --malloc-lib now must be one of the directories /usr/lib,
/usr/lib64, /usr/lib/i386-linux-gnu, or /usr/lib/x86_64-linux-gnu. In addition, the
31
MySQL 5.7 Release Notes
--mysqld and --mysqld-version options are accepted only on the command line, not in option
files. (Bug #24464380)
References: See also: Bug #24619033, Bug #82920.
• It was possible to write log files ending with .ini or .cnf that later could be parsed as option files.
The general query log and slow query log can no longer be written to a file ending with .ini or
.cnf. (Bug #24388753)
• Privilege escalation was possible by exploiting the way REPAIR TABLE used temporary files. (Bug
#24388746)
• If the basedir system variable was set at server startup from the command line or option file, the
value was not normalized (on Windows, / was not replaced with \). (Bug #23747899, Bug #82125)
• kevent statement timer subsystem deinitialization was revised to avoid a mysqld hang during
shutdown on OS X 10.12. (Bug #23744004, Bug #82097)
• For accounts for which multiple GRANT statements applied, mysqlpump could fail to dump them all.
(Bug #23721446)
• The MYSQL_ADD_PLUGIN macro had a spelling error that caused MYSQL_SERVER not to be defined.
(Bug #23508762, Bug #81666)
• In-place ALTER TABLE operations which when executed separately caused no table rebuild could
when combined into a single statement result in a table rebuild. (Bug #23475211, Bug #81587)
• For keyring plugins, the data access layer is now created only as necessary, not once per operation,
which improves keyring performance. (Bug #23337926)
• A blank server name in CREATE SERVER statements produced a server exit rather than an error.
(Bug #23295288)
• The optimizer failed to check a function return value for an area calculation, leading to a server exit.
(Bug #23280059)
• The server could fail to free memory allocated for execution of queries that used generated columns.
(Bug #23205454)
References: This issue is a regression of: Bug #22392268.
• mysqlpump output for triggers that contained multiple statements in the trigger body failed to load
correctly. (Bug #23072245)
• Queries that satisfied the following conditions could return different results than in MySQL 5.6: 1) A
subquery appeared in the select list; 2) The subquery contained a WHERE condition that referenced
a value in the outer query; 3) The outer query contained a GROUP BY that required creation of a
temporary table. (Bug #23049975)
• Passwords that were rejected by the validate_password plugin were written by the server to the
error log as cleartext. (Bug #22922023)
• A prepared statement that used a parameter in the select list of a derived table that was part of a join
could cause a server exit. (Bug #22392374, Bug #24380263)
• MEDIUMINT columns used in operations with long integer values could result in buffer overflow. (Bug
#19984392)
• A spurious ER_NO_SUCH_TABLE error could occur when attempting to execute a prepared CREATE
TABLE ... SELECT statement that used a temporary table in the FROM clause and called a stored
function. The same error could occur for a nonprepared version of the statement if used in a stored
procedure when the procedure was re-executed. (Bug #16672723, Bug #68972)
32
MySQL 5.7 Release Notes
• EINTR handling in the client library has been fixed so that interrupted read and write calls are retried.
Previously, EINTR was ignored. (Bug #82019, Bug #23703570)
Changes in MySQL 5.7.14 (2016-07-29, General Availability)
• Compilation Notes
• Performance Schema Notes
• sys Schema Notes
• Test Suite Notes
• X Plugin Notes
• Functionality Added or Changed
• Bugs Fixed
Compilation Notes
• CMake support was added for compiling with Developer Studio 12.5. (Bug #82249, Bug #24303829,
Bug #81274, Bug #23212938)
Performance Schema Notes
• The INFORMATION_SCHEMA INNODB_LOCKS and INNODB_LOCK_WAITS tables are now
deprecated, to be removed in MySQL 8.0, which provides replacement Performance Schema tables.
sys Schema Notes
• The sys schema now has a quote_identifier() function that, given a string argument,
produces a quoted identifier suitable for inclusion in SQL statements. (Bug #22011361, Bug #78823)
• Output from the sys schema diagnostics() procedure now includes the Tls_version column
from the mysql.slave_master_info system table.
Test Suite Notes
• mysql-test-run.pl now has a --manual-boot-gdb option that is similar to --boot-gdb but
attaches the debugger to the server during the bootstrapping process, permitting the use of a remote
debugger. (Bug #23090633)
X Plugin Notes
• The Protobuf decoder class limited the number of nested objects to 50 (the default value). (Bug
#23707238, Bug #82025)
• The statement list_objects incorrectly reported a table as a collection. (Bug #23631240)
• When using SSL, only TLSv1 connections were being accepted. The fix ensures that all TLS
versions supported by the server are accepted. (Bug #23524243)
• The create_collection statement created a collection table with a unique key index on the
'_id' column instead of on the primary key. (Bug #23284569)
• Attempting to list objects using the list_objects statement without explicitly setting the database
name resulted in the collection being incorrectly classified as a table. (Bug #23205895, Bug #81248)
• Tests relating to X Plugin have been moved to rapid/plugin/x/test. (Bug #23151414)
• Setting protocol related variables such as net_read_timeout, net_write_timeout, and
net_retry_count, from a session using X Protocol returned unexpected results. The fix ensures
33
MySQL 5.7 Release Notes
that protocol variables are set only from sessions using MySQL Protocol, and errors are correctly
detected for sessions using X Protocol.
Functionality Added or Changed
• The %global compatver value for RPM packages for RHEL/OEL and Fedora releases was
updated from 5.6.25 to 5.6.31. (Bug #23038018)
References: See also: Bug #22980983.
• Specifying an empty value for the --port option (for example, --port=, --port="") is now
deprecated and results in a warning. An empty value will be an error in MySQL 8.0. (Bug #23023457,
Bug #80903)
Bugs Fixed
• Performance: A flaw in the allocation of memory for appending string values caused some
operations to be performed slowly, including creation of tables having generated columns and inserts
of large values into JSON columns. (Bug #80556, Bug #22843444)
References: See also: Bug #22157531, Bug #22239803.
• InnoDB: Full-text search auxiliary tables could be dropped by one session while being access by
another. (Bug #23742339)
• InnoDB: Selecting full-text index information schema tables for a deleted table caused a
segmentation fault. (Bug #23479595)
• InnoDB: A tablespace operation did not properly update the SYS_VIRTUAL system table. (Bug
#23325659)
• InnoDB: Rollback of a full-text index synchronization operation raised an assertion. The rollback
operation attempted to acquire a mutex still held by the background synchronization thread. (Bug
#23320569)
• InnoDB: After compressing a table, an incorrect data length was passed to an internal tablespace
encryption function, causing an assertion. (Bug #23279788)
References: This issue is a regression of: Bug #22956469.
• InnoDB: An R-tree page lock placed during a search operation prevented an undo operation within
the same transaction from merging pages. (Bug #23241575)
• InnoDB: A bulk load insert of a record with a compressed size greater than half of the compressed
page size resulted in infinite B-tree page splitting when compressing the uncompressed page. (Bug
#23120933)
• InnoDB: A lock order violation related to InnoDB full-text search caused errors and raised an
assertion. (Bug #23120005)
References: This issue is a regression of: Bug #22996488.
• InnoDB: In read-only mode, InnoDB attempted to set a corrupt bit in the SYS_INDEXES system
table. In read-only mode, the corruption should only be marked in memory. (Bug #23077748)
• InnoDB: InnoDB attempted to materialize non-key virtual generated columns that were not required
for partitioning. (Bug #23037025)
References: This issue is a regression of: Bug #21864838.
• InnoDB: An insert operation on a table containing virtual and spatial indexes raised an assertion due
to an invalid parent path encountered during page splitting. (Bug #23008863)
34
MySQL 5.7 Release Notes
• InnoDB: An ALTER TABLE operation on a table with an indexed virtual column raised an assertion.
(Bug #22965271)
• InnoDB: Adding or dropping a virtual generated column could raise an assertion due to a table
handle held by an active memcached connection. (Bug #22922527)
• InnoDB: A full-text query that involved a large number of records exceeded the result cache limit and
caused a server exit. (Bug #22709692, Bug #80296)
• InnoDB: InnoDB did not block the creation of a foreign key constraint with referential actions on the
base column of a stored generated column. (Bug #22687023, Bug #80304)
• InnoDB: The optimizer failed to mark the columns required for MATCH function evaluation when the
secondary index used for the full-text query was not chosen by the optimizer. (Bug #22679209, Bug
#80298)
• InnoDB: In READ COMMITTED isolation level, InnoDB unnecessarily acquired the lock_sys
mutex at COMMIT for a transaction block consisting of read-only SELECT statements. Thanks to Zhai
Weixiang for the patch. (Bug #22617328, Bug #76728)
• InnoDB: Setting innodb_monitor_enable to all did not enable all counters. (Bug #22576241,
Bug #80083)
• InnoDB: InnoDB now permits defining a foreign key constraint with a cascading referential action
on the base column of an indexed virtual column, and defining cascading referential actions on
non-virtual foreign key columns that are explicitly included in a virtual index. (Bug #22469130, Bug
#79772)
• InnoDB: An assertion was raised during rollback of an ALTER TABLE operation that dropped and
added a secondary index. (Bug #22005726)
• Partitioning: In some cases, an issue with partition pruning being attempted a second time during
optimization after all partitions had already been pruned at parsing time led to an assert. (Bug
#23194259)
• Replication: A lack of cleanup in binlog.binlog_index led to sporadic failures in the
i_binlog.binlog_index_crlf_check test. (Bug #23645554)
• Replication: Replication slaves could exit trying to apply an UPDATE row event containing virtual
generated columns received from a master that was set to binlog_row_image=minimal. (Bug
#23604483)
• Replication: After upgrading from MySQL 5.6, MySQL 5.7 slaves were not handling replication
channels correctly. This was due to the upgrade procedure inverting the order of two fields of the
mysql.slave_master_info table (Channel_Name and Tls_version). The fix avoids this
inversion and adds a check to ensure that the Channel_name is correctly used as the primary key.
(Bug #23180202)
• Replication: The i_rpl.rpl_relay_log_index_inconsistency test was not preserving the
slave server state in certain situations. The fix changes the test to use start_slave.inc instead. (Bug
#22850741)
• Replication: When dealing with large GTID sets (bigger than 64 kilobytes when
converted to a string), the replication_connection_status field was truncating the
RECEIVED_TRANSACTION_SET. The fix updates replication_connection_status to correctly
display large GTID sets, and also updates various GTID set related functions to avoid any future
problems with large GTID sets. (Bug #22369630)
• Replication: On a GTID-based replication slave running with --gtid-mode=on, --log-bin=OFF
and using --slave-skip-errors, when an error was encountered that should be ignored
Exec_Master_Log_Pos was not being correctly updated, causing Exec_Master_Log_Pos
to loose synchrony with Read_master_log_pos. If a GTID_NEXT was not specified, the slave
35
MySQL 5.7 Release Notes
would never update its GTID state when rolling back from a single statement transaction. The
Exec_Master_Log_Pos would not be updated because even though the transaction was finished,
its GTID state would show otherwise. The fix removes the restraint of updating the GTID state when
a transaction is rolled back only if GTID_NEXT is specified. (Bug #22268777)
• Replication: Uncleared information related to user-defined variables could result in a server exit for
DROP TEMPORARY TABLE statements. (Bug #22157118)
• Replication: A server initialized with --gtid-mode=on and --enforce-gtid-consistency=on
created a large and unnecessary GTID set. The fix adjusts the initialization process to eliminate the
creation of these GTID sets. (Bug #22102456, Bug #78972)
• Replication: An incorrectly formed server_uuid read in from auto.conf could cause an
unexpected halt. (Bug #21936933)
• Replication: After issuing a PURGE BINARY LOGS statement, if the binary log index file was not
available, for example because it had been opened by another application such as MEB, the server
could stop unexpectedly. Although this situation was rare, the handling has been made more robust
to avoid unexpected halts and more informative errors are provided. (Bug #20381055)
• Replication: The constructor of Rows_event has been improved to not decode the supplied row
event one byte at a time. Thanks to Davi Arnaut for the contribution. (Bug #82003, Bug #23699294)
• Replication: A new function has been added to the channel service interface to get a channel's
retrieved_gtid_set. (Bug #81694, Bug #23519893)
• Replication: The initialize process now checks if the binary log is enabled while processing a
compiled statement. In such cases it disables binary logging, which avoids filling the binary log
unnecessarily (and generating GTIDs) for MySQL initialization statements. (Bug #81628, Bug
#23490641)
• Replication: Slaves running MySQL version 5.7.11 and later were always using SSL/TLS when the
server supported it, regardless of the MASTER_SSL option. This was due to the addition of the -ssl-mode option, which defaults to preferring an SSL connection. The fix ensures that slaves do not
use SSL when MASTER_SSL=0. (Bug #81223, Bug #23197529)
• Replication: The mysql-test-run.pl option --skip-rpl now correctly skips all replication
tests. Thanks to Daniel Black for the contribution. (Bug #80894, Bug #23021140)
• Replication: When --gtid-mode=off, issuing a PURGE BINARY LOGS TO file statement
causes the system to read the whole file. Depending on the size of the file this could cause the
server to stall for a few seconds. This was due to the way binary log files were being searched for the
Previous_gtids value. The fix adds an optimization to stop the reading of the binary log file if it
is supposed only to read the lost GTIDs and a Previous_gtids event is found. (Bug #80889, Bug
#23054591)
• Replication: When using row-based replication and InnoDB, replication slaves reverted to using an
older locking scheme when a transaction had already acquired an AUTOINC lock related to a LOAD
FILE or INSERT ... SELECT type of statement, reducing replication slave performance. The fix
ensures that sql_command is set correctly for any of the DML events such as WRITE_ROWS_EVENT,
UPDATE_EVENT, and DELETE_EVENT. (Bug #79324, Bug #22247668)
• Replication: A MySQL version 5.5 slave does not have a server_uuid and replication identified
servers by their server_id. Starting from MySQL version 5.6, replication masters detected a
zombie dump thread based only on a slave's server_uuid value, under the assumption that each
slave has a unique UUID. Connecting a MySQL 5.5 slave to a MySQL 5.6 and later master meant
that the master was unable to detect zombie dump threads that were created to serve slaves running
versions older than MySQL 5.6. The fix ensures that a master now first checks if a slave has a
server_uuid set. If it is set, zombie dump thread detection happens based on the slave's UUID. If
a slave's server_uuid is not set, zombie dump thread detection happens based on server_id.
(Bug #77195, Bug #21179199)
36
MySQL 5.7 Release Notes
• Replication: With slave_skip_errors enabled there were still special cases when slave errors
were not being correctly ignored. For example:
• When opening and locking a table failed.
• When field conversions failed on a server running row-based replication.
In these cases the error was considered critical and it was not respecting the state of
slave_skip_errors. The fix ensures that with slave_skip_errors enabled, all errors reported
during applying a transaction are correctly handled. This means that in such a set up, upon receiving
an error with the log_warnings option set to greater than 1, if the error can be ignored then the
warning is printed into the error log and the server continues as it does in the case of other ignored
errors. (Bug #70640, Bug #17653275)
• Replication: When using statement-based or mixed binary logging format with --read-only=ON, it
was not possible to modify temporary tables. (Bug #62008, Bug #12818255)
References: See also: Bug #14294223, Bug #16561483.
• Solaris: The CMake configuration was too aggressive in making symbols invisible, resulting in link
problems with GCC 5.3 on Solaris. (Bug #23344916, Bug #81593)
• Solaris: On Solaris, a misaligned memory buffer could cause a server exit when selecting from the
global_status Performance Schema table. (Bug #81065, Bug #23097305)
• MySQL Server upgrades performed using RPM packages failed when upgrading from MySQL 5.6
Community to MySQL 5.7 Community or MySQL 5.6 Commercial to MySQL 5.7 Commercial. (Bug
#23736787)
• On CentOS, mysqld installed from a MySQL Community distribution failed to start if a my.cnf file
with no datadir value specified was used. (Bug #23721277, Bug #82049)
• The -DWITH_EDITLINE=system CMake option failed with recent versions of the editline library.
(Bug #23708332, Bug #25391997, Bug #84501)
• Executing prepared statements with the audit_log plugin installed could cause a server exit. (Bug
#23699991)
• The sys schema ps_trace_statement_digest() procedure failed for statements not supported
by EXPLAIN, for statements for which EXPLAIN could not find tables, and for statements with no
digest found during the monitored period. (Bug #23621189)
• On RPM-based systems, it is now easier to install multiple client library versions, such as for the
case that you want to maintain compatibility with older applications linked against previous libraries.
To install an older client library, use the --oldpackage option with rpm. For example, to install
mysql-community-libs-5.5 on an EL6 system that has libmysqlclient.20 from MySQL
5.7, use a command like this:
rpm --oldpackage -ivh mysql-community-libs-5.5.50-2.el6.x86_64.rpm
(Bug #23605713, Bug #81384)
• A SELECT Performance Schema tables when an internal buffer was full could cause a server exit.
(Bug #23550835, Bug #23298025, Bug #81464)
• The code for reading character set information from Performance Schema statement events tables
(for example, events_statements_current) did not prevent simultaneous writing to that
information. As a result, the SQL query text character set could be invalid, which could result in a
server exit. Now an invalid character set causes SQL_TEXT column truncation. (Bug #23540008)
• An error message spelling error was corrected. Thanks to Derek Jones for the patch. (Bug
#23525874, Bug #81713)
37
MySQL 5.7 Release Notes
• In the Performance Schema, allocating a record when a buffer was full could lead to a server exit.
(Bug #23515302)
• Several issues for Debian/Ubuntu packages were fixed:
• The mysql-systemd-start script in the mysql-community-server package depended on
mysqladmin for the ping command. Packages including this script now are made dependent on
the mysql-community-client package.
• The systemd service still used mysqld_safe. It now uses mysqld --daemonize.
• Entering a blank root password during the installation process caused installation to hang.
• MySQL upgrades failed to create a missing data directory.
• In addition, CMake-generated packaging for Debian/Ubuntu packages was refactored for improved
maintainability.
(Bug #23501369, Bug #81647, Bug #22972977, Bug #21236550, Bug #21228746, Bug #22833016,
Bug #23582336)
• A buffer overflow in the regex library was fixed. (Bug #23498283)
• Upgrading from native MySQL 5.6 Debian/Ubuntu packages to Oracle-supplied MySQL 5.7
packages caused server restart failures. (Bug #23498230)
• Audit log filtering against the user was performing comparisons against USER(), not
CURRENT_USER(). (Bug #23344762, Bug #81591)
• After upgrading only the server using RPM packages, the server could fail to start, complaining about
a bad errmsg.sys file. (Bug #23338603)
References: This issue is a regression of: Bug #18518216.
• Several issues were addressed in the sys schema stored procedures that show enabled or disabled
Performance Schema setup:
• Enabled and disabled accounts were shown as [email protected], not [email protected]
• Disabled users in ps_setup_show_disabled were called enabled_users.
• ps_setup_show_enabled() showed disabled objects.
• setup_actors content was not filtered (all rows were returned whether the actor was enabled or
disabled).
• Output order is more deterministic.
(Bug #23335880, Bug #81564, Bug #22066096, Bug #78874)
• Upgrading from native Ubuntu 5.7.12 packages to MySQL 5.7.13 packages failed with conflict
messages. (Bug #23327563)
• For debug builds, the server exited abnormally if a shutdown command was issued while the
audit_log plugin was loaded and an active connection existed. (Bug #23310864)
• The server could fail to interpret expired passwords as expired. (Bug #23291841)
• Certain arguments to NAME_CONST() could cause a server exit. (Bug #23279858)
• For unit-testing with the MySQL test suite, the make unit-test command is no longer available.
The ctest program should be used instead. See http://dev.mysql.com/doc/dev/mysql-server/
PAGE_UNIT_TESTS_MAIN_TEST_RUNS.html. (Bug #23273434, Bug #81389)
38
MySQL 5.7 Release Notes
• Audit log plugins (including query rewrite plugins, which use the audit API) were being acquired and
released per statement, negatively affecting scalability. To improve performance, these plugins now
are acquired once and released only when the connection ends. (Bug #23236404, Bug #81298)
• The -fexpensive-optimizations option to GCC caused ARM64 and PowerPC builds to
compute floating-point operations slightly differently from other platforms. CMake now checks for this
problem and disables the option as necessary. (Bug #23046775)
• The test_service_sql_api.test_session_general_log test case now cleans up the
general_log table by truncating it at the end of the test. Thanks to Daniel Black for the patch. (Bug
#23021111, Bug #80895)
• Lines written to the error log had no space separating the timestamp and thread ID columns if the
thread ID took five or more characters. (Bug #23005009, Bug #80854)
• For the innodb_buffer_stats_by_schema and innodb_buffer_stats_by_table sys
schema views, the pages_hashed and pages_old columns were incorrect. Thanks to Tsubasa
Tanaka for the patch. (Bug #22988461, Bug #80833)
• An incorrect result could be returned for a query using a merged derived table or a view when
compared to a similar query using a base table directly, if the query included a WHERE condition in a
scalar subquery inside a HAVING condition of the main query block. (Bug #22967439)
• ST_GeomFromGeoJSON() treated JSON NULL as invalid input. Now it treats JSON NULL as SQL
NULL and thus returns SQL NULL for JSON NULL input. (Bug #22930020, Bug #80712)
• For the host_summary_by_statement_latency and x
$host_summary_by_statement_latency sys schema views, the max_latency column was
incorrect. (Bug #22848110, Bug #80569)
• ST_Distance() could raise an assertion for NULL return values. (Bug #22760390)
• In the absence of SQL_CALC_FOUND_ROWS, FOUND_ROWS() for a UNION statement always
returned the actual number of rows found even when LIMIT was present. (Bug #22602381, Bug
#80148)
• A statement containing a format specifier resulted in a server exit when the query rewrite plugin tried
to log the statement. (Bug #22601485)
• With the query cache enabled, executing a prepared statement with CURSOR_TYPE_READ_ONLY
and then again with CURSOR_TYPE_NO_CURSOR caused the server to return an error. (Bug
#22559575, Bug #80026)
• mysql_real_connect() was not thread-safe when invoked with the
MYSQL_READ_DEFAULT_FILE or MYSQL_READ_DEFAULT_GROUP option enabled. (Bug #22322504,
Bug #79510)
• With GTIDs enabled, XA COMMIT on a disconnected XA transaction within a multiple-statement
transaction raised an assertion. (Bug #22173903)
• The sys schema create_synonym_db() function failed if the synonym name was a reserved word
or contained backtick (`) characters. (Bug #22011361, Bug #78823)
• The sys schema host_summary view could fail with a division-by-zero error. (Bug #21970078)
• The GCC workaround for compiling on ARM64 added by Bug #21552524 is needed only for GCC
before 5.2.1. (Bug #21845828)
References: See also: Bug #21552524.
• The sys schema format_path() function replaced substrings of the path name argument without
verifying that the substrings were delimited by path name separators. Replacement now works
39
MySQL 5.7 Release Notes
correctly, including on Windows. A consequence is that backslashes in Windows path names are no
longer converted to forward slashes in the result. (Bug #21512106)
• MySQL now supports compiling using the GCC __atomic builtins introduced in GCC 4.7 that permit
a more efficient implementation of the MySQL atomics API. These __atomic builtins are only used
for platforms where the old GCC __sync builtins are not available, such as PowerPC where the
server otherwise would not build. (Bug #21221500)
• If a stored function updated a view for which the view table had a trigger defined that updated
another table, it could fail and report an error that an existing table did not exist. (Bug #21142859,
Bug #76808)
• mysql_upgrade failed to upgrade the sys schema if a sys database directory existed but was
empty. (Bug #81352, Bug #23249846, Bug #22875519)
• The bundled Protobuf sources (under the extra directory) were upgraded from version 2.6.0 to
2.6.1. (Bug #81280, Bug #23213376)
• Protobuf is currently used only by the X Plugin, but MySQL builds built the protobuf libraries and
executables even if X Plugin building was disabled with -DWITH_RAPID=0. (Bug #81066, Bug
#23097750)
• A compilation error was corrected for a make_link() call when compiling in C++11 mode. Thanks
for Daniel Black for the contribution. (Bug #80996, Bug #23080289)
• Two mysql-test-run.pl tests (ctype_gb18030_binlog and ctype_ldml) failed to produce
repeatable output due to improper cleanup. Thanks to Daniel Black for the patch. (Bug #80896, Bug
#23021095)
• MySQL failed to build with GCC 6 using the default mode for C++ of -std=gnu++14. The CMake
configuration has been adjusted to explicitly set the mode to -std=gnu++03 for GCC 6. (Bug
#80371, Bug #22732697)
• Ubuntu packages create the root user account using the auth_socket authentication plugin to
achieve secure-by-default installation if installation was done with a blank root password. However,
auth_socket was being used even if the password was not blank. (Bug #80137, Bug #22594846,
Bug #23321113, Bug #81518)
• Compiling the InnoDB memcached plugin did not work on some platforms where MySQL was
configured using -DWITH_LIBEVENT=system. (Bug #80073, Bug #22573379, Bug #23567441)
• The client-side plugin deinitialization function signature was changed from int (*deinit)() to
int (*deinit)(void) to avoid warnings when compiling with -Wstrict-prototypes. (Bug
#78177, Bug #21680094, Bug #81419, Bug #23282498)
Changes in MySQL 5.7.13 (2016-06-02, General Availability)
• Account Management Notes
• Audit Log Notes
• Configuration Notes
• Packaging Notes
• Security Notes
• X Plugin Notes
• Functionality Added or Changed
• Bugs Fixed
40
MySQL 5.7 Release Notes
Account Management Notes
• In MySQL 5.7.8, the maximum length of MySQL user names was increased from 16 to 32
characters, but some applicable contexts for this increase were overlooked. Additional changes in
maximum user name length now have been applied:
• The size of these mysql system table columns is increased:
• The definer column of the event and proc tables
• The grantor column of the procs_priv and tables_priv tables
In each case, the column previously was defined as CHAR(77), where 77 was chosen to permit a
[email protected]_name string containing a user name up to 16 characters, a @ character, and a
host name up to 60 characters. Each column now is defined as CHAR(93), reflecting an increase
in permitted user name length from 16 to 32 characters.
• A similar change from CHAR(77) to CHAR(93)applies to the DEFINER column of these
INFORMATION_SCHEMA tables: EVENTS, ROUTINES, TRIGGERS, VIEWS. Along with the changes
to INFORMATION_SCHEMA tables, output from any corresponding SHOW statements now displays
DEFINER values up to 93 characters. Examples of affected statements: SHOW EVENTS, SHOW
TRIGGERS, SHOW PROCEDURE STATUS.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate the changes to the mysql system database. A server from MySQL
5.7.13 or higher for which mysql_upgrade has not been run continues to permit a maximum of
77 characters in the system tables mentioned previously, and an ER_USER_COLUMN_OLD_LENGTH
error will occur in those system table contexts where a [email protected]_name value from 78 to 93
characters long is given.
Audit Log Notes
• The audit_log plugin that forms the basis for MySQL Enterprise Audit now supports fine-grained
filtering of events. This enables a reduction in the number of log entries written to the audit log file,
which increases overall performance due to fewer write operations during log recording. It also
simplifies subsequent audit log processing in terms of readability and processing time.
Fine-grained audit log filtering is rule based, implemented using tables that store filter definitions
and a set of user-defined functions (UDFs) that enable filter manipulation. To simplify installing the
tables and UDFs along with the audit_log plugin, an installation script is now provided. For more
information, see Installing or Uninstalling MySQL Enterprise Audit, and Audit Log Filtering.
By default, audit log filtering now logs no auditable events for any users. This differs from legacy
audit log behavior (before MySQL 5.7.13), which logs all auditable events for all users; to produce
log-everything behavior, see the installation instructions.
References: See also: Bug #21464781, Bug #71855.
Configuration Notes
• On platforms for which systemd support is installed, systemd has the capability of managing
multiple MySQL instances. For details, see Managing MySQL Server with systemd. Consequently,
mysqld_multi and mysqld_multi.server are not installed because they are unnecessary. (Bug
#81093, Bug #23134620)
Packaging Notes
• support-files/MacOSX/ReadMe.txt is no longer included in MySQL distributions. (Bug
#81038, Bug #23088916)
Security Notes
41
MySQL 5.7 Release Notes
• Security Fix: The linked OpenSSL library for the MySQL Commercial Server has been updated to
version 1.0.1t. For a description of issues fixed in this version, see http://www.openssl.org/news/
vulnerabilities.html.
This change does not affect the Oracle-produced MySQL Community build of MySQL Server, which
uses the yaSSL library instead. (Bug #23229564)
• MySQL Server now includes an SQL interface for keyring key management, implemented as a set of
user-defined functions (UDFs) that access the functions provided by the internal keyring service. For
more information, see General-Purpose Keyring Key-Management Functions. For information about
the keyring service functions invoked by the UDFs, see The Keyring Service. For general keyring
information, see The MySQL Keyring.
X Plugin Notes
• The minimum number of X Plugin worker threads dropped below the number of threads configured
by mysqlx_min_worker_threads. (Bug #23074173)
• During installation of X Plugin, the DROP USER statement of an internal user was being added to
the binary log, while the matching CREATE USER statement was not. This was causing an error
in replication as the internal user did not exist on slaves. The fix ensures that the DROP USER
statement is not added to the binary log. (Bug #22989849)
• An error occurred when using method chaining to group results, for example Crud.Find({ name:
$.name, count:count(*) }).GroupBy($.name);. (Bug #22950240)
• X Plugin threads were registered in the Performance Schema tables as thread/sql/
daemon_plugin. This has been changed to thread/mysqlx/worker. (Bug #22901644)
• When a Mysqlx_idle_worker_thread_timeout was configured, once the timeout had
completed worker threads consumed 100% of CPU when they should have been idle. (Bug #81236,
Bug #23204368)
• Client disconnections were logged as EOF. The log message has been improved to Peer
disconnection. (Bug #81199, Bug #23178878)
Functionality Added or Changed
• JSON: This release adds an unquoting extraction operator ->>, sometimes also referred to as an
inline path operator, for use with JSON documents stored in MySQL. The new operator is similar to
the -> operator, but performs JSON unquoting of the value as well. For a JSON column mycol and
JSON path expression mypath, the following three expressions are equivalent:
• JSON_UNQUOTE( JSON_EXTRACT(mycol, "$.mypath") )
• JSON_UNQUOTE(mycol->"$.mypath")
• mycol->>"$.mypath"
The ->> operator can be used in SQL statements wherever JSON_UNQUOTE(JSON_EXTRACT())
would be allowed. This includes (but is not limited to) SELECT lists, WHERE and HAVING clauses, and
ORDER BY and GROUP BY clauses.
For more information, see Functions That Search JSON Values, and JSON Path Syntax. (Bug
#78736, Bug #21980346)
• For better separation of output from multiple statements, mysqltest now flushes output sent to
stdout when the output destination is not a file. Previously, flushing occurred only for file output.
(Bug #21435906)
• The version of the tcmalloc library included in MySQL distributions was very old. It has been
removed and is no longer included with MySQL. (Bug #80994, Bug #23068660)
42
MySQL 5.7 Release Notes
• The my_make_scrambled_password() function in the C client library was restricted earlier in
MySQL 5.7 (not exported to client programs). The function has once again been made visible to
client programs. (Bug #80974, Bug #23061746)
• It is possible to use ALTER TABLE to change the default value of a column col_name, which
may change the value of a generated column expression that refers to the column using
DEFAULT(col_name). For this reason, ALTER TABLE operations that change the definition of
a column now cause a table rebuild if any generated column expression uses DEFAULT(). (Bug
#80299, Bug #22680839)
Bugs Fixed
• InnoDB: A rollback operation run concurrently with an operation involving a virtual generated column
caused a server exit. (Bug #23313102)
References: This issue is a regression of: Bug #21869656.
• InnoDB: Potential buffer overflow issues were corrected for the InnoDB memcached plugin. (Bug
#23187607)
• InnoDB: An ALTER TABLE operation that added an AUTO_INCREMENT column on a table with
virtual columns raised an assertion. (Bug #23052231)
• InnoDB: Statements executed in a transaction that was rolled back asynchronously by a higher
priority transaction caused a deadlock error and subsequent replication failure. (Bug #23021168, Bug
#80898)
• InnoDB: An ALTER TABLE operation that attempted to add a virtual generated column and a fulltext index raised an assertion. (Bug #23014521)
• InnoDB: The full-text index cache was freed during a background index cache synchronization. (Bug
#22996488)
• InnoDB: A full-text index operation raised an assertion. (Bug #22963169)
• InnoDB: Memory was allocated to I/O slots unnecessarily, causing an apparent memory leak. (Bug
#22956469, Bug #80772)
• InnoDB: An ALTER TABLE operation raised an assertion when attempting to create a key
containing a generated column. (Bug #22951879)
• InnoDB: A startup failure due to an invalid option resulted in a server exit after a subsequent restart.
An error returned by the innobase_start_or_create_for_mysql function was not checked.
(Bug #22939581, Bug #80761)
• InnoDB: An ALTER TABLE ... IMPORT TABLESPACE operation on file-per-table tablespace
containing an encrypted table failed when run in a different session than the preceding ALTER
TABLE ... DISCARD TABLESPACE operation. (Bug #22918999, Bug #80708)
• InnoDB: A FLUSH TABLES operation on a table with a discarded tablespace raised an assertion.
(Bug #22899690, Bug #80669)
• InnoDB: A DML operation involving a table with a virtual column raised an assertion. (Bug
#22899305)
• InnoDB: An invalid read at innobase_get_computed_value() raised a Valgrind error. (Bug
#22898168, Bug #80667)
• InnoDB: Online DDL operations like ALTER TABLE ... ADD INDEX were not permitted for tables
created with the ENCRYPTION attribute. (Bug #22897921)
• InnoDB: InnoDB memcached code assumed the nonexistence of the htonll() function on OS X,
resulting in a build failure on OS X 10.10 and later. (Bug #22865112)
43
MySQL 5.7 Release Notes
• InnoDB: Starting the server in read-only mode failed when encrypted tables were present. The call
to fil_encryption_rotate() was not skipped when the server was started in read-only mode.
(Bug #22723797)
• InnoDB: An R-tree purge operation raised an assertion. (Bug #22698076, Bug #80327)
• InnoDB: An INSERT operation on a table with a FULLTEXT index and FTS_DOC_ID column
failed because the inserted FTS_DOC_ID value exceeded the permitted gap between consecutive
FTS_DOC_ID values. To avoid this problem, the permitted gap between the largest used
FTS_DOC_ID value and new FTS_DOC_ID value was raised from 10000 to 65535. (Bug #22679185)
• InnoDB: Validation code for transparent page compression incorrectly permitted
innodb_strict_mode=OFF, which allowed the COMPRESSION attribute to be applied to a general
tablespace. Page compression is only supported with file-per-table tablespaces. (Bug #22615096,
Bug #80182)
• InnoDB: An memory order issue related to atomic operations caused assertion failures on ARM64
and POWER platforms. (Bug #22608616)
• InnoDB: DROP TABLESPACE returned an error if the remote general tablespace data file was
missing. (Bug #22232892, Bug #79330)
• InnoDB: An ALTER TABLE operation that changed table row format from COMPACT to COMPRESSED
raised an assertion. A function involved in the operation passed incorrect page size information. (Bug
#22046353)
• InnoDB: With innodb_autoinc_lock_mode=0, multiple threads waiting for a table-level lock
caused an unexpected deadlock. (Bug #21983865, Bug #78761)
• InnoDB: A race condition in trx_kill_blocking() raised an assertion. (Bug #21508537)
• InnoDB: An OPTIMIZE TABLE operation on a table with a full-text index raised an assertion. (Bug
#21378944)
• InnoDB: A buffer pool load operation resulted in a Cannot allocate 0 bytes error. (Bug
#21371070)
• InnoDB: A FLUSH TABLES ... FOR EXPORT operation appeared to stall. A loop in the
ibuf_contract_in_background function failed to exit. (Bug #21133329, Bug #77011)
• InnoDB: A full-text query raised an assertion. Under certain circumstances, DDL operations such as
ALTER TABLE ... RENAME caused full-text auxiliary tables to be removed on server restart. (Bug
#13651665)
• Replication: With gtid_mode=ON, executing an empty query before setting gtid_next made the
latter action fail. It was because only statements that do not change the data can be executed before
one can successfully change gtid_next, and an empty query was not considered one of those
“safe” statements. This fix allows the setting of gtid_next after an empty query. (Bug #22811150)
• Replication: Slaves running MySQL 5.7 could not connect to a MySQL 5.5 master due to an error
retrieving the server_uuid, which is not part of MySQL 5.5. This was caused by changes in the
method of retrieving the server_uuid. (Bug #22748612)
References: This issue is a regression of: Bug #21455603.
• Replication: Setting certain semisynchronous-replication configurations on the master server when
semisynchronous replication was not enabled on it might cause the server to exit. This fix prevents
the unexpected exits to occur in the situation. (Bug #22602324)
• Replication: The variable explicit_defaults_ts was not initialized during the construction of
a Query_event object. That caused Valgrind warnings for dependency on an uninitialized variable.
This fix makes sure the variable is initialized. (Bug #22110916, Bug #78999)
44
MySQL 5.7 Release Notes
References: This issue is a regression of: Bug #18885916, Bug #72794.
• Replication: In the next_event() function, which is called by a slave's SQL thread to read the
next even from the relay log, the SQL thread did not release the relaylog.log_lock it acquired
when it ran into an error (for example, due to a closed relay log), causing all other threads waiting
to acquire a lock on the relay log to hang. With this fix, the lock is released before the SQL thread
leaves the function under the situation. (Bug #21697821)
References: See also: Bug #20492319.
• Replication: A partially failed statement was not correctly consuming an auto-generated or specified
GTID when binary logging was disabled. The fix ensures that a partially failed DROP TABLE, a
partially failed DROP USER or a partially failed DROP VIEW consume respectively the relevant GTID
and save it into @@GLOBAL.GTID_EXECUTED and mysql.gtid_executed table when binary
logging is disabled. (Bug #21686749)
• Replication: When using row-based replication in a cascading or circular replication setup, where
a master is replicating to server 1 which is then replicating to server 2, merge tables were not being
correctly applied on server 2. This could cause an unexpected halt on server 2 while server 1 was
unaffected. (Bug #17018343)
• Replication: An intermittent ASan error was being reported on the rpl.rpl_checksum_cache
test. The error reported was related to the binary log sender doing a heap-use-after-free on a given
memory address. (Bug #78995, Bug #22109863)
• Replication: mysqldump has been updated to make it compatible with multi-source replication.
Now when replication channels other than the default channel are found, mysqldump --dumpslave outputs a CHANGE MASTER TO statement for each replication channel. (Bug #78467, Bug
#21855705)
• Replication: If a multi-threaded replication slave running with relay_log_recovery=1 stopped
unexpectedly, during restart the relay log recovery process could fail. This was due to transaction
inconsistencies not being filled, see Handling an Unexpected Halt of a Replication Slave. Prior to this
fix, to recover from this situation required manually setting relay_log_recovery=0, starting the
slave with START SLAVE UNTIL SQL_AFTER_MTS_GAPS to fix any transaction inconsistencies and
then restarting the slave with relay_log_recovery=1. This process has now been automated,
enabling relay log recovery of a multi-threaded slave upon restart automatically. (Bug #77496, Bug
#21507981)
• Fedora builds now are configured using -DMYSQL_MAINTAINER_MODE=0 to silence GCC 6
warnings. (Bug #23274249)
• Allocation of a large number (2^20) of Performance Schema index statistic objects could cause a
server exit. (Bug #23188107)
• If the keyring_okv plugin configuration directory was missing, attempts to rotate the InnoDB
master key could cause a server exit. (Bug #23149683)
• INSERT with ON DUPLICATE KEY UPDATE and REPLACE on a table with a foreign key constraint
defined failed with an incorrect duplicate entry error rather than a foreign key constraint
violation error. (Bug #23135731)
References: This issue is a regression of: Bug #78853, Bug #22037930.
• Contention in Performance Schema mutex instrumentation creation and destruction has been
reduced, such that mutexes for which instruments are frequently created and destroyed are
maintained in separate pages from those for which instruments are rarely created and destroyed.
(Bug #22965826)
• With certain build options, an uninitialized variable in get_key_scans_params() could produce a
compilation error. (Bug #22916059)
45
MySQL 5.7 Release Notes
• Adding new tokens to the parser caused query digest values to change. (Bug #22906606)
• For debug builds, CONCAT_WS() could raise an assertion if there was nothing to append. (Bug
#22888420)
• Fixed Valgrind warnings for failed LEAST() evaluations. (Bug #22883278)
• INET_NTOA() could cause a server exit when producing an error message. (Bug #22881810)
References: This issue is a regression of: Bug #22042027.
• The my_write() call could cause a server exit if it attempted to check the current connection and
the connection had been killed. (Bug #22867809)
References: This issue is a regression of: Bug #21688407.
• Invoking Enterprise Encryption functions in multiple threads simultaneously could cause a server
exit. (Bug #22839278)
• Setting log_syslog_tag to NULL could cause a server exit. (Bug #22834781)
References: This issue is a regression of: Bug #22180046.
• If the expression for an indexed generated column contained an AND or OR operator, the optimizer
could choose that index too often and create execution plans that produced incorrect results. (Bug
#22810883)
• CREATE TABLE statements in mysqlpump output could be missing KEY clauses and would not load.
(Bug #22726732)
• Attempting to use Enterprise Encryption functions after creating and dropping them could cause a
server exit. (Bug #22669012)
• Setting sort_buffer_size to a very large value could cause some operations to fail and result in
a server exit. (Bug #22594514)
• For an InnoDB table containing generated columns, using the table in a join could result in a server
exit due to improper error checking. (Bug #22561845)
• REPLACE on a table with an indexed generated column could cause a server exit if the index prefix
length was calculated incorrectly. (Bug #22445211)
• An UPDATE operation affecting a virtual generated BLOB column could cause a server exit. (Bug
#22444212)
• SHOW CREATE TABLE for a table containing a generated column could cause a server exit or
produce an Illegal mix of collations error. (Bug #22392268)
• On a slave server, replication of an UPDATE statement that updated an indexed BLOB virtual
generated column of an InnoDB table could cause a server exit. (Bug #22241015)
• An assertion could be raised when a deadlock occurred due to a SELECT ... GROUP BY ...
FOR UPDATE query executed using a Loose Index Scan. (Bug #22187476)
• mysqlpump could exit due to improper handling of error conditions in a dump thread. (Bug
#22017120)
• Several potential buffer overflow issues were corrected. (Bug #21977380, Bug #23187436, Bug
#23202778, Bug #23195370, Bug #23202699)
• If the CA certificate as given to the --ssl-ca option had an invalid path, yaSSL returned
an error message different from OpenSSL. Now both return SSL connection error:
SSL_CTX_set_default_verify_paths failed. (Bug #21920657)
46
MySQL 5.7 Release Notes
• Installing MySQL from a yum or zypper repository resulted in /var/log/mysqld.log being
created with incorrect user and group permissions. (Bug #21879694, Bug #78512)
• With show_compatibility_56=OFF, SHOW VARIABLES and SHOW STATUS statements having a
WHERE clause did not work. (Bug #21783883)
• The audit_log plugin failed to abort the current operation when told to do so by a plugin handler
for a MYSQL_AUDIT_PARSE_PREPARSE event. (Bug #21457956)
• Memory leaks reported by Valgrind for mysqlpump were fixed. (Bug #21237667)
• Some string functions returned one or a combination of their parameters as their result. If one of the
parameters had a non-ASCII character set, the result string had the same character set, resulting in
incorrect behavior when an ASCII string was expected. (Bug #18740222)
• On Fedora 24, upgrades using a Community MySQL Server RPM failed to replace an installed
MariaDB Galera server due to a change in the MariaDB package. (Bug #81390, Bug #23273818)
• The mysql_read_defaults_options() function was missing a break statement, causing any
option value for the --ssl-cipher option also to be applied to the --tls-version option, with
unpredictable results. (Bug #81139, Bug #23129821)
• A DELETE from joined tables using a derived table in the WHERE clause failed if one of the joined
tables was used in the derived table. (Bug #81014, Bug #23074801)
• Compiling of clients that used the MySQL C API could fail if they used an obsolete path to
mysql.h or <mysql/mysql.> and did not set the include path. This was due to use of #include
<file_name> notation rather than #include "file_name" in internal MySQL header files, which
have been adjusted. (Bug #80935, Bug #23047194)
• MySQL did not compile under Solaris 12 using Sun Studio. To correct this, instances of
__attribute__ were changed to MY_ATTRIBUTE. (Bug #80748, Bug #22932576)
• The service_mysql_keyring.h and services.h header files misspelled
mysql_keyring_service_st as mysql_keyring_file_service_st. (Bug #80688, Bug
#22908232)
• The fix for Bug #79194 did not cover the eq_ref access method, with the result that left joins could
return incorrect results.
Note
This bug fix has a very small negative performance effect such that it fails
to cache an eq_ref-accessed row that is on the inner side of an outer join.
Regular inner joins are not affected.
(Bug #80526, Bug #22833364)
References: This issue is a regression of: Bug #79194, Bug #22176604.
• The sanity() macro in strings/decimal.c produced Valgrind warnings due to reading
uninitialized buffer contents. (Bug #80461, Bug #22782203, Bug #22839915)
• Starting the server with --initialize failed if the keyring_file_data system variable was also
set at startup. To handle this, with --initialize the server no longer skips registration of plugins
loaded with the --early-plugin-load option. (Bug #80451, Bug #22777039)
• Loading the Rewriter query rewrite plugin when there was no query_rewrite database resulted
in Valgrind warnings. (Bug #80333, Bug #22710312)
• The optimizer transformed EXISTS (SELECT * ...) constructs to EXISTS (SELECT 1 ...)
before all columns in the inner subquery had been resolved, which could result in rejection of valid
47
MySQL 5.7 Release Notes
queries that included a HAVING clause without GROUP BY in the subquery. (Bug #80231, Bug
#22655856)
• For a server compiled with -DWITH_PERFSCHEMA_STORAGE_ENGINE=0, a memory leak could
occur for buffered log messages used during server startup. (Bug #80089, Bug #22578574)
• A query could return incorrect results under these conditions: A column with a default value
contained NULL; SELECT DISTINCT or a GROUP BY clause was used and the column containing
the NULL value was part of the select list; an InnoDB temporary table was used during query
processing. (Bug #79591, Bug #22343910)
• A null pointer dereference of a parser structure could occur during stored procedure name validation.
(Bug #79396, Bug #22286421)
• Database initialization failed during installation using Ubuntu 15.10 packages. (Bug #79377, Bug
#22252900)
• mysql_upgrade failed to widen the User and Proxied_user columns in the
mysql.proxies_priv system table from 16 to 32 characters. (Bug #78254, Bug #21762656)
• Failure of UNINSTALL PLUGIN could lead to inaccurate or confusing errors for subsequent
INSTALL PLUGIN operations. (Bug #74977, Bug #20085672)
• mysqld_multi displayed misleading error messages when it was unable to execute
my_print_defaults. (Bug #74636, Bug #19920049)
• Previously, upgrading the server using an RPM package (including installation using yum) required
upgrading the client package to the same MySQL version, which may be undesirable for some
installations. This rule has been relaxed so that upgrading to a General Availability (GA) server
version requires only that some GA client version be installed, which is less likely to require a client
upgrade. (Bug #72230, Bug #18518216)
• mysqldump failed silently with no error message when it encountered an error while executing
FLUSH LOGS. (Bug #71783, Bug #18284273)
Changes in MySQL 5.7.12 (2016-04-11, General Availability)
Starting with MySQL Server 5.7.12, we are introducing the concept of Rapid Plugins. Out of the box,
5.7.12 follows the same stability promise as our current release process, but it also allows for plugins
with additional functionality to be installed very easily. The first plugin to be released with MySQL
Server 5.7.12 following this concept is the new X Plugin, which exposes a new communications
protocol called the X Protocol.
The expanded capabilities of the X Protocol enable us to provide the new X DevAPI in our MySQL
Connectors and Client applications, like the new MySQL Shell. The goal of the X DevAPI is to support
a new schema object type called document collections as well as relational and combined document
store/relational capabilities. Now developers, designers and DBAs can deploy MySQL databases that
implement document store, relational, or hybrid document/relation models. For documentation about
how to get started using MySQL as a document store, see Using MySQL as a Document Store.
• Configuration Notes
• Packaging Notes
• Security Notes
• Functionality Added or Changed
• Bugs Fixed
Configuration Notes
48
MySQL 5.7 Release Notes
• Incompatible Change: To load a keyring plugin, the --early-plugin-load option is used.
Previously, the default --early-plugin-load option value was the name of the keyring_file
plugin library file. Now the default value is empty.
Important
InnoDB tablespace encryption requires the keyring_file plugin to be
loaded prior to InnoDB initialization, so this change of default --earlyplugin-load value introduces an incompatibility for upgrades from 5.7.11
to 5.7.12 or higher. Administrators who have encrypted InnoDB tablespaces
must take explicit action to ensure continued loading of the keyring_file
plugin: Start the server with an --early-plugin-load option that names
the plugin library file. For example, on platforms where the plugin library file
suffix is .so, use these lines in the server my.cnf file:
[mysqld]
early-plugin-load=keyring_file.so
On other platforms, adjust the file name suffix as necessary. For more
information, see The MySQL Keyring.
(Bug #80413, Bug #22748738)
Packaging Notes
• The obsolete support-files/MySQL-shared-compat.spec.sh file was removed from MySQL
distributions. (Bug #22525609)
Security Notes
• Security Fix: The linked OpenSSL library for the MySQL Commercial Server has been updated to
version 1.0.1s. For a description of issues fixed in this version, see http://www.openssl.org/news/
vulnerabilities.html.
This change does not affect the Oracle-produced MySQL Community build of MySQL Server, which
uses the yaSSL library instead. (Bug #22685885, Bug #22923458)
• InnoDB: The InnoDB tablespace encryption feature, which provides at-rest data encryption for
InnoDB tables, now supports Oracle Key Vault for encryption key management. Oracle Key Vault
support relies on the keyring_okv plugin which is available in MySQL Enterprise Edition. A
secure and robust encryption key management solution such as OKV is critical for security and
for compliance with various security standards. For more information, see InnoDB Tablespace
Encryption.
• MySQL Enterprise Edition now includes a keyring_okv plugin that uses Oracle Key Vault as a
back end for keyring storage. For more information, see The MySQL Keyring.
Functionality Added or Changed
• For queries with many OR conditions, the optimizer now is more memory-efficient and less likely to
exceed the memory limit imposed by the range_optimizer_max_mem_size system variable. In
addition, the default value for that variable has been raised from 1536000 to 8388608. (Bug #79450,
Bug #22283790)
Bugs Fixed
• InnoDB; Partitioning: INSERT and SELECT statements against a partitioned InnoDB table having
generated columns were not always handled correctly. (Bug #22444530)
References: See also: Bug #21776494, Bug #21824564, Bug #21864838.
49
MySQL 5.7 Release Notes
• InnoDB: An error was returned on startup when a replication slave attempted to access an
encrypted table. The server UUID used to compose the master key name was not persisted to the
tablespace data file, resulting in the use of an incorrect master key. (Bug #22912582)
• InnoDB: In debug builds, an unnecessary buf_block_align() call could cause a latching
order violation. A DML operation resulted in a page mismatch assertion due to the same
buf_block_align() call. (Bug #22709463, Bug #21321238)
• InnoDB: An ALTER TABLE ... ADD COLUMN operation on a table with virtual columns raised an
assertion. (Bug #22650296)
• InnoDB: An unnecessary comparison in tablespace encryption code caused compiler warnings.
(Bug #22645816)
• InnoDB: INNODB_SYS_TABLESPACES could report incorrect ALLOCATED_SIZE and
FILE_SIZE values for a general tablespace created outside of the data directory. The
i_s_dict_fill_sys_tablespaces() function generated an incorrect remote file path. (Bug
#22590095, Bug #80070)
• InnoDB: In debug builds, an update operation on a table with virtual columns raised an assertion.
(Bug #22572997)
• InnoDB: Modifications were made to InnoDB code to handle warnings when compiling with
Microsoft Visual Studio 2015. (Bug #22542547, Bug #79964)
• InnoDB: Running REPLACE operations on multiple connections resulted in a hang. (Bug #22530768,
Bug #79185)
• InnoDB: Operations relating to tabespace encryption resulted in a hang on FreeBSD. (Bug
#22520464, Bug #79901)
• InnoDB: MySQL stalled when synchronizing the InnoDB full-text index cache. (Bug #22516559, Bug
#16510576, Bug #73816)
• InnoDB: A CREATE TABLE ... DATA DIRECTORY operation failed to create a table while
innodb_flush_method was set to O_DIRECT. (Bug #22180006, Bug #79200)
References: This issue is a regression of: Bug #21113036.
• InnoDB: In debug builds, a buffer pool resizing operation resulted in a segmentation violation. The
buf_pool_resizing variable was not protected. (Bug #22179317)
• InnoDB: The innodb_open_files setting could exceed the open files limit. (Bug #22111472)
• InnoDB: InnoDB attempted crc32 checksum validation instead of innodb after a crc32 checksum
validation failure, causing repeated crc32 checksum validation attempts. Checksum validation order
is now optimized dynamically. Thanks to Daniel Black for the patch. (Bug #79725, Bug #22452597)
• Replication: When a slave with no binary log connected to a Group Replication master, it failed with
Error running query, but no information about the failure was available from the output of SHOW
SLAVE STATUS or in the replication_applier_status_by_worker table. (Bug #22699395)
• Replication: Setting relay_log_recovery=1 generated an error during recovery, due to
repositories not being initialized. (Bug #22523554)
• Replication: Issuing STOP SLAVE caused a spurious Error reading packet from server:
Lost connection to MySQL server during query message to be written to the error log.
With this fix, when connection to the master is lost, the abort_slave flag is checked and the error
message is printed only if the flag is not set. (Bug #22305605, Bug #79504)
References: See also: Bug #12977988, Bug #22290309.
50
MySQL 5.7 Release Notes
• Replication: When the binary log was disabled, the GTID specified by gtid_next when committing
an empty transaction caused by a BEGIN statement was saved in gtid_executed when it should
not have been. This did not occur when the binary log was enabled.
Now, when gtid_next is set for the current session, BEGIN raises an
ER_CANT_DO_IMPLICIT_COMMIT_IN_TRX_WHEN_GTID_NEXT_IS_SET error inside any
transaction regardless of whether binary logging is enabled, since this statement causes an implicit
commit. In this case, the GTID specified by gtid_next is not saved in gtid_executed. (Bug
#22130929)
• Replication: When replication was configured but not started on a slave, the variable
currently_executing_gtid was not properly initialized, but it would be used if the
performance_schema table replication_applier_status_by_worker was queried, causing assertion
failures and pointer issues. With this fix, the variable is now properly initialized at the construction of
the Relay_log_info object. (Bug #21953132, Bug #78722)
• Replication: RESET SLAVE ALL could delete a channel even when master_pos_wait and
wait_until_sql_thread_after_gtid were still waiting for transactions to be applied. This
could cause a MySQL server exit when the functions tried to access the channel that was deleted.
Now, a channel reference counter was added that is increased if the channel should not be deleted
when the functions are running. RESET SLAVE ALL will wait for no reference, and then it will delete
the channel. (Bug #21842399, Bug #78445)
• Replication: When relay_log_recovery=1, a slave server, at its initialization, still tried to scan
the relay log files in order to update Retrieved_Gtid_Set and the transaction parser state, which
was an unnecessary waste of resources because the slave I/O thread would just be initialized to the
SQL thread position in the new relay log file. With this fix, the slave server skips scanning the relay
log files when relay_log_recovery=1. (Bug #21798355, Bug #78352)
• Replication: XA transactions were not handled correctly when --gtid-mode=ON and the binary log
was disabled. It was because on both master and slave servers, the GTID state was sometimes not
saved and the GTID ownership was sometimes not cleaned up. This fix makes sure those steps are
now properly performed. (Bug #21618727)
References: See also: Bug #22165138, Bug #77740, Bug #21452916.
• Replication: When a multi-threaded slave stopped with an error, the same error message was
printed three times. Now, the SQL thread's kill acceptance status is saved, and only printed once.
(Bug #21198611, Bug #77237)
• Replication: When using a multi-threaded slave with relay_log_info_repository set to
TABLE, the slave applier thread failed to write XA transactions to the worker configuration. (Bug
#20988291)
• Replication: mysqlbinlog --verbose displayed BINARY and VARBINARY data as ordinary
strings, causing any single quote (“'”) or backslash (“\”) among the data to be printed as such, which
was confusing to the users and, in the case of a backslash, caused the next character to be skipped.
This fix makes mysqlbinlog print the characters' hexadecimal values (“\x27” for single quote and
“\x5c” for backslash) instead. (Bug #20836250)
• Replication: The test case main.merge failed when the variables binlog_format was set to
“ROW,” as the server tried to get information for table creation for a child table before it was opened.
With this fix, the server skips getting information for the table in the situation. (Bug #20574550, Bug
#75976)
• Replication: When a server was run with relay_log_info_repository=TABLE and the
--super-read-only option enabled, a statement which caused an update to the slave info
tables, such as STOP SLAVE or CHANGE MASTER TO, resulted in a 'STOP SLAVE' failed:
1290: The MySQL server is running error, preventing the statement being executed. The
fix ensures that replication operations are permitted regardless of the setting of read_only and
super_read_only. (Bug #78963, Bug #22097534)
51
MySQL 5.7 Release Notes
• Replication: Valgrind tests of mysqlbinlog revealed some memory leaks. (Bug #78223, Bug
#21697461, Bug #78966)
• Replication: If a query on a master generated an error and partial results were written to the binary
log, for example due to a DROP TABLE IF EXISTS statement applying to multiple tables that would
break foreign key constraints, when a slave configured with replication filters encountered the query
it could be incorrectly binary logged. This caused errors such as:
Last_SQL_Error: Query caused different errors on master and slave. Error
on master: message (format)='Cannot delete or update a parent row: a
foreign key constraint fails' error code=1217 ; Error on slave: actual
message='no error', error code=0. Default database: 'db1'. Query: 'DROP
TABLE IF EXISTS `table1` /* generated by server */'
There were two fixes required for this bug.
• If a DROP TABLE statement used to drop a single table fails, to avoid partial results causing this
bug the query is not written to the binary log. If a DROP TABLE statement used to drop a list of
tables fails, any partial results it generates are written to the binary log with an error.
• When a query that generates an error as expected was received by a slave but it was skipped due
to replication filters, the slave was incorrectly checking the error. The fix for Bug #76493 ensures
that this comparison of the expected error from the master with the actual error from the slave
does not happen.
(Bug #77684, Bug #21435502)
References: See also: Bug #20797764, Bug #76493.
• JSON: Error messages raised by JSON_KEYS() and JSON_EXTRACT() contained the wrong data.
(Bug #78699, Bug #22026278)
• RTRIM() on large strings could be very slow. (Bug #22884187)
References: This issue is a regression of: Bug #18315770, Bug #12368495.
• Integer overflow could occur during client handshake processing, leading to a server exit. (Bug
#22722946)
• Missing initializers in the query plan constructor resulted in Valgrind warnings. (Bug #22573117)
• mysqlpump failed (syntax error) when a view name contained a space character. View names are
now quoted. (Bug #22505474)
• UNHEX() with an invalid argument could result in garbage characters in the warning message. (Bug
#22358933)
• Improper host name checking in X509 certificates could permit man-in-the-middle attacks. (Bug
#22295186, Bug #22738607)
• For debug builds, when an indexed nonnullable generated column with an empty string generated
expression was updated during an insert for a duplicated key, there was an optimization that resulted
in the server failing to find the duplicated index, causing an assertion to be raised. (Bug #22195364)
• A boolean mode full-text search caused a segmentation fault. (Bug #22176795)
• Queries on generated columns that used WITH ROLLUP could raise an assertion. (Bug #22131343)
• For a prepared statement that used a derived table, an assertion could be raised at execute time
when checking statement privileges. (Bug #22108567)
• Concurrent selecting and flushing of a FEDERATED table while killing connections accessing it could
result in a server exit. (Bug #21918190)
52
MySQL 5.7 Release Notes
• For debug builds, when a query using join buffering and one of the tables inserted into the join buffer
was accessed using a dynamic range scan on an index containing a virtual column, a Valgrind error
occurred when writing columns to the join buffer. (Bug #21872184)
• After iterations of uninstalling and installing the audit_log plugin, the server could hang. (Bug
#21796658)
• With a LOCK TABLES statement in effect, access to Performance Schema tables could fail, as could
SHOW STATUS with show_compatibility_56=OFF. (Bug #21789221)
• Executing GRANT PROXY statements after altering the definition of the mysql.user system table
could result in a server exit. (Bug #21699037)
• Certain error messages included part of the SQL statement that produced them, possibly exposing
data. (Bug #21682356)
• Although it is possible to create nontemporary tables using the prefix #sql, Performance Schema
assumed that tables named using this prefix were temporary and could be ignored. Performance
Schema now uses table attributes other than the name to identify temporary tables. (Bug
#21105475, Bug #22532368, Bug #79934)
• Account filtering performed by the audit_log plugin incorrectly used the account named by the
USER() function rather than the CURRENT_USER() function (the latter being the account used for
authentication). (Bug #19509471, Bug #22454245, Bug #77553)
• NAME_CONST() can return null if incorrect arguments are given. In some cases, this was not
handled and could cause a server exit. (Bug #19143243, Bug #26361149)
• Character set conversion operations on NULL parameters to prepared statements could cause a
server exit. (Bug #18823979)
• Loose Index Scan was not chosen for queries that had an equality condition. (Bug #18109609)
• Long or complex SQL statements could cause the parser to run out of memory. The new
parser_max_mem_size system variable now enables control over the maximum amount of
memory available to the parser. The default value places no limit on memory available, but the value
can be reduced to protect against out-of-memory situations. (Bug #14744160)
• A Valgrind warning for memory_free_noop() was silenced. (Bug #80457, Bug #22782197)
• The MySQL server failed to start if built with the -m32 option on Solaris/Sparc, due to improper static
data alignment in init_delegates(). (Bug #80445, Bug #22763880)
• The plugin_keyring.h header file misspelled st_mysql_keyring as
st_mysql_keyring_file. (Bug #80414, Bug #22748867)
• For shared-memory connections on Windows, the client library opened a handle on a mutex but did
not close it. Subsequent attempts to restart the server on the other end of the connection failed if the
client still had the mutex handle open. (Bug #80234, Bug #22646779)
• mysqld attempted to initialize plugins specified using the --early-plugin-load option when the
--help option was specified. (Bug #80077, Bug #22573767)
• ALTER USER IDENTIFIED WITH ... expired the account password, even if the authentication
plugin did not support password expiration. (Bug #79999, Bug #22551523)
• Some Performance Schema global instruments, if not enabled at server startup, could be in a
state where it was not possible to enable them at runtime. This restriction has been lifted. Affected
instruments include mutex, rwlock, cond, and socket instances. Thanks to Zhang Yingqiang for
the patch. (Bug #79784, Bug #22517278, Bug #66515, Bug #14532176)
• Setting the super_read_only system variable at server startup had no effect. (Bug #79328, Bug
#22233503)
53
MySQL 5.7 Release Notes
• These audit_log plugin issues were corrected:
• Calling my_message() from the MYSQL_AUDIT_GENERAL_CLASS handler resulted in infinite
recursion.
• Diagnostic messages were improved for the case when the MYSQL_AUDIT_GENERAL_CLASS
handler returned nonzero.
• Calling my_message() from the MYSQL_AUDIT_SERVER_STARTUP_CLASS handler did not abort
server startup as it should have.
• SHOW GLOBAL VARIABLES produced different output for the null_audit_abort_value
system variable with show_compatibility_56 enabled and disabled.
(Bug #79079, Bug #22136709, Bug #79091, Bug #22142166, Bug #79092, Bug #22142209, Bug
#21783798)
• For INSERT and UPDATE operations that caused FOREIGN KEY constraint violations, errors were
reported rather than warnings when the IGNORE keyword was used. (Bug #78853, Bug #22037930)
References: See also: Bug #23135731.
• Using the server session service, executing an SQL statement from a thread with no VIO context
could raise an assertion. (Bug #78734, Bug #21959409)
• CREATE VIEW statements that used the TIMESTAMPDIFF() function with MICROSECOND as the unit
resulted in incorrect view definitions. (Bug #78506, Bug #21877062)
• For an existing user, CREATE USER IF NOT EXISTS produced an error rather than a warning.
Similarly, for an nonexisting user, ALTER USER IF EXISTS produced an error rather than a
warning. (Bug #78374, Bug #21807286)
• For some queries, an Index Merge access plan was chosen over a range scan when the cost for the
range scan was the same or less. (Bug #77209, Bug #21178196)
• UNHEX() could attempt a left shift of a negative number. (Bug #73964, Bug #19642015)
• EXPLAIN for SELECT ... FOR UPDATE statements acquired locks. (Bug #72858, Bug #18899860)
• Processlist state information was not updated correctly for LOAD DATA INFILE and could show a
state different from executing. (Bug #69375, Bug #16912362)
Changes in MySQL 5.7.11 (2016-02-05, General Availability)
• Compilation Notes
• Data Type Notes
• Installation Notes
• Packaging Notes
• Security Notes
• Functionality Added or Changed
• Bugs Fixed
Compilation Notes
• A value of system is now permitted for the WITH_BOOST CMake option. If this option is not set or
is set to system, it is assumed that the correct version of Boost is installed on the compilation host
in the standard location. In this case, the installed version of Boost is used rather than any version
included with a MySQL source distribution. (Bug #22224313)
54
MySQL 5.7 Release Notes
• In addition to the mysql-5.7.11.tar.gz source tarball, another tarball named mysqlboost-5.7.11.tar.gz is provided. The new tarball contains everything in the first tarball, but also
contains all the required Boost header files in a subdirectory named boost. This is for the benefit of
those who do not have the correct Boost version installed and do not wish to or cannot download it.
To build from this source distribution, add -DWITH_BOOST=boost to the CMake command line.
Data Type Notes
• Bit functions and operators comprise BIT_COUNT(), BIT_AND(), BIT_OR(), BIT_XOR(), &, |,
^, ~, <<, and >>. Currently, bit functions and operators require BIGINT (64-bit integer) arguments
and return BIGINT values, so they have a maximum range of 64 bits. Arguments of other types are
converted to BIGINT and truncation might occur.
An extension for MySQL 8.0 changes this cast-to-BIGINT behavior: Bit functions and operators
permit binary string type arguments (BINARY, VARBINARY, and the BLOB types), enabling them to
take arguments and produce return values larger than 64 bits. Consequently, bit operations on binary
string arguments in MySQL 5.7 might produce different results in MySQL 8.0. To provide advance
notice about this potential change in behavior, the server now produces warnings for bit operations
for which binary string arguments are not converted to integer in MySQL 8.0. These warnings afford
an opportunity to rewrite affected statements. To explicitly produce MySQL 5.7 behavior in a way that
will not change after an upgrade to 8.0, cast bit-operation binary string arguments to convert them to
integer. For more information and examples, see Bit Functions and Operators.
Installation Notes
• Previously, mysqld --initialize required the data directory to not exist or, if it existed, to be
empty. Now an existing data directory is permitted to be nonempty if every entry either has a name
that begins with a period (.) or is named using an --ignore-db-dir option. (Bug #79250, Bug
#22213873)
Packaging Notes
• Packaging support was added for Ubuntu 15.10. (Bug #79104, Bug #22147191)
Security Notes
• Security Fix: The linked OpenSSL library for the MySQL Commercial Server has been updated
from version 1.0.1p to version 1.0.1q. For a description of issues fixed in this version, see http://
www.openssl.org/news/vulnerabilities.html.
This change does not affect the Oracle-produced MySQL Community build of MySQL Server, which
uses the yaSSL library instead. (Bug #22348181)
• yaSSL was upgraded to version 2.3.9. This upgrade corrects an issue in which yaSSL handled only
cases of zero or one leading zeros for the key agreement instead of potentially any number, which in
rare cases could cause connections to fail when using DHE cipher suites. (Bug #22361038)
• The default value of the default_password_lifetime system variable that controls the global
password expiration policy has been changed from 360 (360 days) to 0 (no password expiration).
The default of 360 sometimes took people by surprise when account passwords expired a year after
upgrading to MySQL 5.7. To continue to use a value other than 0 as the password expiration, start
the server with an explicit setting for default_password_lifetime. For example, use these lines
in an option file:
[mysqld]
default_password_lifetime=360
(Bug #77277, Bug #21284761)
• MySQL Server now supports a keyring service that enables internal server components and
plugins to securely store sensitive information for later retrieval. The implementation includes a
55
MySQL 5.7 Release Notes
keyring_file plugin that stores keyring data in a file local to the server host. For more information,
see The MySQL Keyring, Writing Keyring Plugins, and The Keyring Service.
• MySQL client programs now support an --ssl-mode option that enables you to specify the
security state of the connection to the server. Permitted option values are PREFERRED (establish an
encrypted encrypted connection if the server supports the capability, falling back to an unencrypted
connection otherwise), DISABLED (establish an unencrypted connection), REQUIRED (establish
an encrypted connection, or fail), VERFIFY_CA (like REQUIRED, but additionally verify the server
certificate), VERIFY_IDENTITY (like VERIFY_CA, but additionally verify that the server certificate
matches the host name to which the connection is attempted). For backward compatibility, the
default is PREFERRED if --ssl-mode is not specified.
These clients support --ssl-mode: mysql, mysqladmin, mysqlbinlog, mysqlcheck,
mysqldump, mysqlimport, mysqlshow, mysqlpump, mysqlslap, mysqltest,
mysql_upgrade.
The --ssl-mode option comprises the capabilities of the client-side --ssl and --ssl-verifyserver-cert options. Consequently, both of those options are now deprecated and will be
removed in a future MySQL release. Use --ssl-mode=REQUIRED instead of --ssl=1 or -enable-ssl. Use --ssl-mode=DISABLED instead of --ssl=0, --skip-ssl, or --disablessl. Use --ssl-mode=VERIFY_IDENTITY instead of --ssl-verify-server-cert options.
(The server-side --ssl option is not deprecated.)
For the C API, the new MYSQL_OPT_SSL_MODE option for mysql_options()
corresponds to the --ssl-mode option. The MYSQL_OPT_SSL_ENFORCE and
MYSQL_OPT_SSL_VERIFY_SERVER_CERT options for mysql_options() correspond to the
client-side --ssl and --ssl-verify-server-cert options. They are now deprecated and
will be removed in a future MySQL release. Use MYSQL_OPT_SSL_MODE with an option value of
SSL_MODE_REQUIRED or SSL_MODE_VERIFY_IDENTITY instead.
For more information, see Command Options for Encrypted Connections, and mysql_options().
In consequence of this change, the minor C API version number was incremented.
Functionality Added or Changed
• InnoDB: A new InnoDB configuration option, innodb_tmpdir, allows you to configure a separate
directory for temporary files created during online ALTER TABLE operations that rebuild the table.
This option was introduced to help avoid MySQL temporary directory overflows that could occur as a
result of large temporary files created during online ALTER TABLE operations. innodb_tmpdir can
be configured dynamically using a SET statement.
Online ALTER TABLE operations that rebuild a table also create an intermediate table file in the
same directory as the original table. The innodb_tmpdir option is not applicable to intermediate
table files. (Bug #19183565)
• InnoDB: InnoDB now supports at-rest data encryption for InnoDB tables stored in file-per-table
tablespaces. Encryption is enabled by specifying the ENCRYPTION option when creating or altering
an InnoDB table. For more information, see InnoDB Tablespace Encryption.
• Replication: The log_statements_unsafe_for_binlog variable was added to provide control
over whether the warnings generated by error 1592 are added to the binary log or not.
• The Valgrind function signature in mysql-test/valgrind.supp was upgraded for Valgrind 3.11.
(Bug #22214867)
• The audit_log plugin now produces events in the MYSQL_AUDIT_TABLE_ACCESS_CLASS class.
These events are abortable. (Bug #21458192)
• The format of log output produced by mysqld_safe now is configurable using the --mysqldsafe-log-timestamps option. This option can be used to produce log timestamps in formats
56
MySQL 5.7 Release Notes
compatible with the server or in formats used by mysqld_safe in older versions of MySQL.
For more information, see mysqld_safe — MySQL Server Startup Script. (Bug #78475, Bug
#21862951)
• The server now supports an --early-plugin-load option that indicates which plugins to load
before loading mandatory built-in plugins and before storage engine initialization. One use for
this option is to load the keyring_file plugin: The InnoDB storage engine uses the keyring
tablespace encryption, so the keyring_file plugin must be loaded early to ensure that it is
available prior to InnoDB initialization.
• Storage engines now can request notification about acquisition and release of exclusive metadata
locks. As result, the LOCK_STATUS column of the metadata_locks Performance Schema table
has two new status values. The PRE_ACQUIRE_NOTIFY and POST_RELEASE_NOTIFY status
values are brief and signify that the metadata locking subsubsystem is notifying interested storage
engines while entering lock acquisition or leaving lock release operations.
• The mysql_plugin utility is deprecated and will be removed in a future version of MySQL.
Alternatives include loading plugins at server startup using the --plugin-load or --pluginload-add option, or at runtime using the INSTALL PLUGIN statement.
• The mysql_kill(), mysql_list_fields(), mysql_list_processes(), and
mysql_refresh() C API functions are deprecated and will be removed in a future version
of MySQL. The same is true of the corresponding COM_PROCESS_KILL, COM_FIELD_LIST,
COM_PROCESS_INFO, and COM_REFRESH client/server protocol commands. Instead, use
mysql_query() to execute a KILL, SHOW COLUMNS, SHOW PROCESSLIST, or FLUSH statement,
respectively.
Bugs Fixed
• InnoDB; Partitioning: When OPTIMIZE TABLE rebuilt a partitioned InnoDB table, it placed the
resulting partition tablespace files (*.ibd files) in the default data directory instead of the directory
specified using the DATA DIRECTORY option. (Bug #75112, Bug #20160327)
• InnoDB: InnoDB failed to update index statistics when adding or dropping a virtual column. (Bug
#22469660, Bug #79775)
• InnoDB: Server method calls in Information Schema interface code were fixed to avoid unnecessary
typecasts. (Bug #22391925)
• InnoDB: A small InnoDB buffer pool size with a large
innodb_stats_persistent_sample_pages setting resulted in a Difficult to find free
blocks in the buffer pool warning. (Bug #22385442)
• InnoDB: memcached connections are blocked from accessing tables that contain an indexed virtual
column. Accessing an indexed virtual column requires a callback to the server, but a memcached
connection does not have access to the server code. (Bug #22384503, Bug #79691)
• InnoDB: InnoDB did not return an informative message when refusing an online ALTER TABLE
operation that attempted to add an index and a virtual column. (Bug #22374827)
• InnoDB: An invalid innodb_saved_page_number_debug setting caused a server exit. (Bug
#22311319, Bug #79516)
• InnoDB: InnoDB failed to free a table object when a compressed table and temporary compressed
table were created in the same shared tablespace. (Bug #22306581)
• InnoDB: In NUMA-related code, the size information passed to the mbind() call in the
buf_chunk_init() function was incorrect. (Bug #22293530, Bug #79434)
• InnoDB: NUMA support was incomplete for online buffer pool resizing operations. (Bug #22293511,
Bug #79354)
57
MySQL 5.7 Release Notes
• InnoDB: A SELECT COUNT(*) query that counted the results of a full-text subquery raised an
assertion. (Bug #22270139)
• InnoDB: InnoDB passed a buffer with an incorrect TINYBLOB data length for a virtual column,
resulting in a purge thread failure. (Bug #22256752)
• InnoDB: A purge failure occurred while deleting data from a table that contained a spatial index.
(Bug #22230442, Bug #22366370)
• InnoDB: An assertion was raised when purge accessed a freed page while attempting to rebuild
virtual column data from the clustered index. (Bug #22204260)
• InnoDB: Only prefix bytes were logged for an indexed virtual column, resulting in an a Clustered
record for sec rec not found error. (Bug #22202788)
• InnoDB: A small buffer pool with an innodb_page_size setting of 64K could cause startup,
bootstrap, and recovery failures. (Bug #22179133, Bug #79201)
• InnoDB: Unreachable code that checks for 32-bit file offsets was removed. (Bug #22163880, Bug
#79150)
• InnoDB: A slow shutdown failure was caused by background threads adding undo records to the
purge history list during or after purge thread exit. (Bug #22154730)
• InnoDB: The InnoDB purge thread died attempting to purge a virtual column index record that was
not delete-marked. (Bug #22141031)
• InnoDB: In debug builds, an ALTER TABLE operation that increased the column length of a virtual
column raised an assertion. (Bug #22139917)
• InnoDB: ut_allocator prepended the allocation payload with a 12-byte header on 32-bit systems,
causing unaligned memory access. On 32-bit SPARC systems, the unaligned memory access
caused a crash during bootstrap. (Bug #22131684)
• InnoDB: In debug builds, an ALTER TABLE operation that added a new virtual column before an
existing virtual column raised an assertion. (Bug #22123674, Bug #22111464)
• InnoDB: InnoDB startup messages related to dumping and loading of the buffer pool were
improved. (Bug #22096661, Bug #78960)
• InnoDB: Support was enabled for ALGORITHM=INPLACE operations that add an index on an
existing virtual column while dropping another virtual column. Support was also enabled for
ALGORITHM=INPLACE operations that add a virtual column and an index. When adding an index on
a newly-added virtual column, purge now skips the uncommitted virtual index. (Bug #22082762)
• InnoDB: The wrong table object was used to compute virtual column values for a query that
accessed multiple instances of the same table. (Bug #22070021)
• InnoDB: A purge thread failure occurred when inserting and deleting spatial data. The child page
number field was not stored during the R-tree search stage. (Bug #22027053)
• InnoDB: Starting the server with an empty innodb_data_home_dir entry in the configuration file
caused InnoDB to look for the buffer pool file in the root directory, resulting in a startup error. (Bug
#22016556, Bug #78831)
• InnoDB: A failure to compute virtual column values caused an excessive number of error messages.
(Bug #21968375)
• InnoDB: An INFORMATION_SCHEMA.INNODB_CMP_PER_INDEX query raised an assertion. A
dictionary mutex was taken while InnoDB populated an in-memory heap table. The mutex was not
released before InnoDB attempted to convert the in-memory heap table to an optimized internal
temporary table. (Bug #21950756, Bug #78714)
58
MySQL 5.7 Release Notes
• InnoDB: To avoid a potential hang and redo log overwrite, the innodb_log_file_size
minimum value was increased from 1MB to 4MB, and the length calculation in
log_margin_checkpoint_age() was revised. (Bug #21924224, Bug #78647)
• InnoDB: A full-text query run under high concurrency caused a server exit due to an invalid memory
access. (Bug #21922532)
• InnoDB: An ALTER TABLE operation on a table partitioned across multiple tablespaces moved
existing partitions to the table's default tablespace, resulting in an assertion on SHOW CREATE
TABLE. Likewise, ALTER TABLE tbl_name TABLESPACE tablespace_name moved existing
partitions to the named tablespace. Only ALTER TABLE ... REORGANIZE PARTITION should
move existing partitions to the table's default tablespace or to a named tablespace. Running ALTER
TABLE tbl_name TABLESPACE tablespace_name on a table partitioned across multiple
tablespaces should only change the table's default tablespace. (Bug #21914047, Bug #22124042,
Bug #79030)
• InnoDB: With a large innodb_sort_buffer_size setting, adding an index on an empty table
performed more slowly than expected. (Bug #21762319, Bug #78262)
• InnoDB: A race condition occurred between fil_names_write() and
file_rename_tablespace_in_mem(). (Bug #21549928)
• InnoDB: Purge attempted to access undo pages that were freed by a preceding undo log truncate
operation, resulting in an assertion. (Bug #21508627)
• InnoDB: InnoDB did not return an informative message when refusing an online ALTER TABLE
operation on a table with a spatial index. (Bug #20111575)
• InnoDB: A compiler barrier was added to ut_relax_cpu(). The ut_always_false dummy
global variable was removed from ut_delay(). (Bug #20045167, Bug #74832)
• InnoDB: Incorrect index values were returned while dropping a virtual column. The altered table
object was used to evaluate virtual column values. (Bug #79773, Bug #22469459)
References: This issue is a regression of: Bug #22082762.
• Partitioning: Subquery scans on partitioned tables with virtual columns could leak memory. (Bug
#79145, Bug #22162200)
• Replication: The behavior of SET GTID_PURGED was not consistent between version 5.6 and 5.7.
The fix ensures that version 5.7 does not initiate a transaction for SET GTID_PURGED statements.
(Bug #21472492)
• Replication: When DML invokes a trigger or a stored function that inserts into an AUTO_INCREMENT
column, that DML has to be marked as an unsafe statement. If the tables are locked in the
transaction prior to the DML statement (for example by using LOCK TABLES), then the DML
statement was not being marked as an unsafe statement. The fix ensures that such DML statements
are marked correctly as unsafe. (Bug #17047208)
• Replication: If pseudo_slave_mode was set to 1 while an XA transaction was in the prepare
stage, an assert was generated. The fix ensures that changes from 0 to 1 can be made during
XA transactions. Note that this variable is solely for internal use by the server. (Bug #79416, Bug
#22273964, Bug #78695, Bug #21942487)
• Replication: When using GTIDs, a GTID-violating statement generates an error in the following
cases:
• enforce_gtid_consistency=ON
• gtid_mode is either ON or ON_PERMISSIVE and gtid_next=AUTOMATIC
• GTID_NEXT=UUID:NUMBER
59
MySQL 5.7 Release Notes
The error prevented the implicit pre-commit, which caused a race condition. This has been fixed by
making the error not prevent the implicit pre-commit from happening. This matches the expected
behavior for GTID-violating DDL statements to implicitly commit the previous transaction before
executing it. (Bug #78543, Bug #21895421)
• Replication: When a slave was configured with log_bin=OFF, the applier (SQL) thread was failing
to correctly roll back partial transactions left in the relay log. The fix ensures that on reconnection, the
applier thread correctly rolls back a partial transaction and starts applying it again from the next relay
log file. (Bug #78211, Bug #21691396)
• Replication: If the server stopped unexpectedly immediately before committing an XA transaction
which had been prepared, and the transaction modified the mysql.gtid_executed table, then the
subsequent recovery aborted due to an innodb_lock_wait_timeout error when it was reading
the mysql.gtid_executed table. To fix the problem, XA transactions are no longer permitted to
modify the mysql.gtid_executed table. (Bug #77740, Bug #21452916)
• Replication: As part of the fix for Bug #16290902, when writing a DROP TEMPORARY TABLE IF
EXISTS query into the binary log, the query is no longer preceded by a USE `db` statement.
Instead the query uses a fully qualified table name, for example DROP TEMPORARY TABLE IF
EXISTS `db`.`t1`;. This changed the application of replicate-rewrite-db filter rules, as
they work only on the default database specified in a USE statement. This caused slaves to fail when
the resulting CREATE TEMPORARY TABLE was applied. The fix ensures that at the time of writing a
DROP TEMPORARY TABLE IF EXISTS query into the binary log, a check is made for the default
database. If it exists then the query is written as USE default_db in the binary log. If a default
database is not present then the query is logged with the qualified table name. (Bug #77417, Bug
#21317739)
• Replication: If generating a GTID for a transaction fails, the transaction is not written
to the binary log but still gets committed. Although running out of GTIDs is a rare
situation, if it did occur an error was written to the binary log as a sync stage error. With
binlog_error_action=ABORT_SERVER, the server aborts on such an error, avoiding data
inconsistency. When binlog_error_action=IGNORE_ERROR, the server continues binary logging
after such an error, potentially leading to data inconsistency between the master and the slave. The
fix changes the error to be correctly logged as a flush stage error. (Bug #77393, Bug #21276561)
• Replication: When using --gtid-mode=on , --enforce-gtid-consistency , and -binlog-format=row, if a user defined function with multiple DROP TEMPORARY TABLE
statements was executed on a master, the resulting binary log caused an error on slaves.
The fix ensures that stored functions and triggers are also considered multi-statement
transactions, and that when --enforce-gtid-consistency is enabled, functions
with CREATE TEMPORARY TABLE or DROP TEMPORARY TABLE statements generate an
ER_GTID_UNSAFE_CREATE_DROP_TEMPORARY_TABLE_IN_TRANSACTION error. (Bug #77354,
Bug #21253415)
• Replication: Stored procedure local variables that were used in an ALTER EVENT statement
were not being replicated correctly. This was related to the fact that CALL statements are not
written into the binary log. Instead each statement executed in a stored procedure is binary logged
separately, with the exception that the statement string is modified so that uses of stored procedure
local variables are replaced with NAME_CONST('spvar_name', 'spvar-value') calls. DDL
statements (which are always binary logged in statement binary log mode irrespective of the current
binary log format) can also use stored procedure local variables and a clash could cause them to not
be replicated correctly. The fix ensures that any stored procedure local variables used in a statement
are replaced with NAME_CONST(...), except for the case when it is a DML statement and the
binary log format is ROW. (Bug #77288, Bug #21229951)
• Replication: DROP TABLE statements are regenerated by the server before being written to
the binary log. If a table or database name contained a non-regular character, such as non-latin
characters, the regenerated statement was using the wrong name, breaking replication. The fix
ensures that in such a case the regenerated name is correctly converted back to the original
60
MySQL 5.7 Release Notes
character set. Also during work on this bug, it was discovered that in the rare case that a table
or database name contained 64 characters, the server was throwing an assert(M_TBLLEN <
128) assertion. The assertion has been corrected to be less than or equal 128. (Bug #77249, Bug
#21205695)
References: See also: Bug #78036, Bug #22261585, Bug #21619371.
• Replication: Irrespective of the current binlog_format setting, DDL that changes metadata on
a master is always identified and written to the binary log in STATEMENT format. Such DDL could
occur from event based SQL statements, such as CREATE EVENT or DROP EVENT, or transactions
that had unsafe functions such as sysdate(). When binlog_format=MIXED and attempting
to replicate such DDL, it was not being correctly identified and therefore was not being correctly
replicated. (Bug #71859, Bug #19286708)
• Microsoft Windows: Thread handle resource leakage could occur when creating threads for
handling connections on Windows, which could lead to Windows servers eventually running out of
handles. (Bug #79714, Bug #22455198)
• JSON: Syntax checks were not always performed when an ALTER TABLE statement changed a
column's type from TEXT to JSON. This could lead to JSON columns containing invalid JSON data.
This issue was observed when the original TEXT column used the utf8mb4_bin collation. (Bug
#79432, Bug #22278524)
• The System-V initialization script for RHEL6 or older failed to enable the mysqld service by default.
(Bug #22600974)
• Some activations of triggers that referenced a NEW value inside a query might cause a server exit.
(Bug #22377554)
• Parsing the output of ST_GeometryType() as a DATETIME value with a default character set of
utf32 caused a server exit. (Bug #22340858)
• For a character set loaded from an XML file, the server could fail to properly initialize its state map,
leading to a server exit. (Bug #22338946)
• Inserting a token of 84 4-byte characters into a full-text index raised an assertion. The maximum
token length was 84 characters up to a maximum of 252 bytes, which did not account for 4-byte
characters. The maximum byte length is now 336 bytes. (Bug #22291765, Bug #79475)
• For some combination of consumers, the Performance Schema prepared statement instrumentation
could cause a server exit. (Bug #22291560)
• If a client attempted to use an unsupported client character set (ucs2, utf16, utf32), the error
message reported to the client differed for SSL and non-SSL connections. (Bug #22216715)
• Data corruption or a server exit could occur if a stored procedure had a variable declared as TEXT
or BLOB and data was copied to that variable using SELECT ... INTO syntax from a TEXT or BLOB
column. (Bug #22203532, Bug #22232332, Bug #21941152)
• For debug builds, with the ONLY_FULL_GROUP_BY SQL mode disabled, the optimizer could attempt
to sort on outer references, causing an assertion to be raised. (Bug #22200984)
• Different handling of YEAR values for INSERT and SELECT could raise an assertion when such
values were used in a generated-column expression. (Bug #22195458)
• For debug builds, for queries involving MIN() or MAX() on an indexed column and a reference to
an unindexed datetime column, the optimizer could attempt to access unread values, causing an
assertion to be raised. (Bug #22186926)
• Geohash decoding (for example, for ST_LongFromGeoHash(), ST_LatFromGeoHash(), and
ST_PointFromGeoHash()) could yield incorrect results due to the rounding algorithm being too
aggressive. (Bug #22165582)
61
MySQL 5.7 Release Notes
• In debug builds, with READ UNCOMMITTED transaction isolation level, a SELECT reading a generated
column using an index could raise an assertion. (Bug #22133710)
• For generated columns, the optimizer could fail to establish the proper table reference, resulting in a
server exit. (Bug #22132822)
• For some combination of consumers, the Performance Schema file instrumentation could fail due to
an attempt to use a NULL pointer while instrumenting temporary file I/O. (Bug #22130453)
• The Performance Schema could raise an assertion based on the (incorrect) assumption that
instrumenting a temporary file open operation always resulted in an instrumented file. (Bug
#22118669)
• An ALTER TABLE statement that added an index on a virtual generated column using the INPLACE
algorithm did not properly report warnings (or errors in strict SQL mode) for problems with virtual
column values. Any subsequent ALTER TABLE on the same table using the COPY algorithm
produced such warnings (or failures in strict SQL mode) due to evaluating the problematic value,
but left the connection in a state that made further INPLACE alterations on the table fail for the same
reason. (Bug #22095783)
• If the left expression of an IN expression was a row subquery that accesses no tables, an assertion
could be raised (in debug builds), or incorrect results could be returned (in release builds). (Bug
#22089623)
• Expressions that match an indexed generated column may be replaced with the generated column
by the optimizer to enable use of the associated index. However, this optimization was not performed
for single-table update and delete statements. The optimizer now extends this replacement
optimization to such statements. (Bug #22077611)
• ANSI SQL mode could cause inconsistencies in processing of generated column expressions. (Bug
#22018979)
• Removal of server session plugins was faulty and could cause a server exit. (Bug #21983102)
• For some queries, if the optimizer used Disk-Sweep Multi-Range Read optimization on generated
columns, the server could exit. (Bug #21980430)
• mysqlpump tries to do as much work in parallel as possible, but the dump threads lacked a
synchronization point before backing up the data, resulting in inconsistent backup. mysqlpump now
locks the server and flushes all the tables using FLUSH TABLES WITH READ LOCK to ensure that
any further connections view the same state of all the databases.
This change lifts the restriction aginst the --single-transaction option being mutually
exclusive with parallelism. When using --single-transaction, it is no longer necessary to
disable parallelism by setting --default-parallelism to 0 and not using any instances of -parallel-schemas. (Bug #21980284)
• A fault in pthread_rwlock_unlock() wherein it decremented the lock counter even for already
unlocked objects could result in deadlock. (Bug #21966621)
• The Performance Schema could acquire a double lock on session system variables, causing a
server hang or (in debug builds) an assertion to be raised. (Bug #21935106)
• Certain queries containing WHERE 0 of the following form could cause a server exit due to
uninitialized reads: SELECT (SELECT col AND constant FROM t WHERE 0) IN (SELECT
constant FROM t1). (Bug #21922202)
• CREATE TEMPORARY TABLE .. SELECT statements involving BIT columns that resulted in a
column type redefinition could cause a server exit or an improperly created table. (Bug #21902059)
• For UPDATE operations on InnoDB tables, there could be a mismatch between the value of a virtual
generated column in the index and the value in the “before” buffer, resulting in a server exit. (Bug
#21875520)
62
MySQL 5.7 Release Notes
• With character_set_server=utf16le, some values of ft_boolean_syntax could cause a
server exit for full-text searches. (Bug #21631855)
• With gtid_mode=ON, concurrent execution of SHOW TABLE STATUS and REVOKE ALL
PRIVILEGES could lead to deadlock in there was a view in the database and REVOKE ALL
PRIVILEGES failed for some but not all of the named users. (Bug #21463167)
• mysqlpump could exit due to incorrect synchronization of view-handling threads during dump
processing. (Bug #21399236, Bug #21447753)
• With LOCK TABLES in force, an attempt to open a temporary MERGE table consisting of a view in its
list of tables (not the last table in the list) caused a server exit. (Bug #20691429)
• For certain prepared statements, the optimizer could transform join conditions such that it used a
pointer to a temporary table field that was no longer available after the initial execution. Subsequent
executions caused a server exit. (Bug #19941403)
• Repeated execution of ALTER TABLE v1 CHECK PARTITION as a prepared statement, where v1
is a view, led to a server exit.
In addition, output for some administrative operations, when they are attempted on a view, changes
from “Corrupt” to “Operation failed”. These include ANALYZE TABLE, OPTIMIZE TABLE, and
REPAIR TABLE, and ALTER TABLE statements that perform ANALYZE PARTITION, CHECK
PARTITION, OPTIMIZE PARTITION, and REPAIR PARTITION operations. (Bug #19817021)
• Valgrind detected some possibly unsafe use of string functions in code used for asymmetric
encryption. (Bug #19688135)
• An out-of-memory failure in join buffer allocation could lead to incorrect results for multiple-table
queries. (Bug #19031409)
• SSL connections ignored any change made by passing the MYSQL_OPT_READ_TIMEOUT option to
the mysql_options() C API function. (Bug #17618162)
• For ALTER TABLE statements, the parser did not support the ALGORITHM clause for some
operations involving tablespaces or partitions. (Bug #17400320)
• Debian packages create the root user account using the auth_socket authentication plugin to
achieve secure-by-default installation if installation was done with a blank root password. However,
auth_socket was being used even if the password was not blank. (Bug #80137, Bug #22594846,
Bug #23321113, Bug #81518)
• Solaris packages failed to note the dependency of the MySQL client library on the libstlport
library. (Bug #79778, Bug #22504264)
• Using systemd to start mysqld failed if configuration files contained multiple datadir lines. Now the
last datadir line is used. (Bug #79613, Bug #22361702)
• A derived table contained in the SET clause of an UPDATE statement should be materialized to avoid
an error about updating a table that is also read in the same statement. Materialization did not occur
for some statements, leading to that error. (Bug #79590, Bug #22343301)
• MySQL 5.7.8 prohibited references to select list columns of the outer query from the HAVING
clause of a correlated subquery in the inner query because they are not permitted by standard SQL.
However, because this is a frequently used extension, it is once again permitted. (Bug #79549, Bug
#22328395)
References: This issue is a regression of: Bug #19823076.
• Installing just shared libraries, clients, and development support files failed to install everything
needed to build client applications because the binary_log_types.h header file was not installed.
(Bug #79531, Bug #22321338)
63
MySQL 5.7 Release Notes
• SHOW CREATE TRIGGER could fail to display all applicable SQL modes. (Bug #79526, Bug
#22313133)
References: This issue is a regression of: Bug #18311187.
• On SELinux, mysqld --initialize with an --init-file option could fail to initialize the data
directory. (Bug #79442, Bug #22314098, Bug #79458, Bug #22286481)
• Hexadecimal and bit literals written to saved view definitions could be truncated. This could also
affect extended EXPLAIN output. (Bug #79398, Bug #22268110)
• ST_Buffer() returned an error for geometries with an SRID different from 0. Nonzero SRID values
now are permitted but ignored (calculations are still done using Cartesian coordinates). (Bug #79394,
Bug #22306745)
• A regression caused failure of the workaround at Restrictions on Subqueries for avoiding
ER_UPDATE_TABLE_USED errors when referencing the same table in a subquery as was used as
target for an UPDATE or DELETE statement. (Bug #79333, Bug #22239474)
• Statements causing multiple parse errors could cause an assertion to be raised. (Bug #79303, Bug
#22222013)
• Some queries with derived tables perform better with materialization than when merged into
the outer query. The optimizer no longer uses merging by default for derived tables containing
dependent subqueries in the select list. (Bug #79294, Bug #22223202)
• ALTER USER and SET PASSWORD did not work at server startup when invoked in the file named
using the --init-file option. (Bug #79277, Bug #22205360)
• When not in strict SQL mode, attempts to implicitly insert NULL into a NOT NULL column resulted in
different behavior depending on whether the table had a trigger. (Bug #79266, Bug #22202665)
• Some replication-only code was not protected with #ifdef and failed to compile with the
WITH_UBSAN CMake option enabled. (Bug #79236, Bug #22190632)
• Configuring MySQL with the -DWITH_UBSAN=ON CMake option resulted in spurious runtime
warnings from comp_err. These are now suppressed. Also, a CMake warning was added
that undefined behavior address sanitizer support is currently experimental. (Bug #79230, Bug
#22190656)
• INSERT INTO ... SELECT statements could insert values other than DEFAULT into generated
columns. (Bug #79204, Bug #22179637)
• With the derived_merge flag of the optimizer_switch system variable enabled, queries that
used a derived table on the inner side of an outer join could return incorrect results. (Bug #79194,
Bug #22176604)
References: See also: Bug #80526, Bug #22833364.
• Memory leaks in libmysqld were corrected. (Bug #79187, Bug #22174219)
• FOUND_ROWS() could return a negative value if the preceding query was a UNION involving
SQL_CALC_FOUND_ROWS and LIMIT ... OFFSET. (Bug #79131, Bug #22155786)
• IN-to-EXISTS subquery transformation could cause SELECT NULL IN (subquery) to return 0
rather than NULL.
IN-to-EXISTS subquery transformation could yield incorrect results for queries for which the table
was nonempty, the subquery on the left side of the IN predicate produced an empty result, and semijoin optimization was disabled. (Bug #78946, Bug #22090717, Bug #74403, Bug #19822406)
• The result from WEIGHT_STRING() could be incorrect when used in a view. (Bug #78783, Bug
#21974321)
64
MySQL 5.7 Release Notes
• For connections made using a Unix socket file, specifying the --ssl-ca option caused the
connection to fail. (Bug #78509, Bug #21878661)
• If server was started with --thread-handling=no-threads, no foreground thread was created
for a client connection. The Performance Schema did not account for the possibility of no foreground
threads for queries on the session_connect_attrs table, causing an assertion to be raised. (Bug
#78292, Bug #21765843)
• mysqlpump generated incorrect INSERT statements for tables that had generated columns. (Bug
#78082, Bug #21650559)
• ALTER TABLE ... CONVERT TO CHARACTER SET operations that used the INPLACE algorithm
were ineffective if the table contained only numeric data types. Also, such operations failed to clean
up their temporary .frm file. (Bug #77554, Bug #21345391)
• Heavy SHOW PROCESSLIST or SELECT ... FROM INFORMATION_SCHEMA.PROCESSLIST
activity could result in the server accepting more than max_connections connections. (Bug
#75155, Bug #20201006)
• When used with the libmysqld embedded server, the mysql_stmt_execute() C API function
failed with a malformed communication packet error, even for simple prepared statements.
(Bug #70664, Bug #17883203)
• Queries using SUM(DISTINCT) could produce incorrect results when there were many distinct
values. (Bug #56927, Bug #11764126, Bug #79648, Bug #22370382)
Changes in MySQL 5.7.10 (2015-12-07, General Availability)
• Security Notes
• Functionality Added or Changed
• Bugs Fixed
Security Notes
• Previously, MySQL supported only the TLSv1 protocol for encrypting connections. TLS support is
now extended to enable a higher level of connection encryption:
• When compiled using OpenSSL 1.0.1 or higher, MySQL supports the TLSv1, TLSv1.1, and
TLSv1.2 protocols.
• When compiled using the bundled version of yaSSL, MySQL supports the TLSv1 and TLSv1.1
protocols.
Because TLSv1.2 requires OpenSSL, support for this protocol is available in binary distributions
only for MySQL Commercial Server, and not for MySQL Community Server (which is compiled using
yaSSL). To enable TLSv1.2 support if you build from source, you must set the WITH_SSL CMake
option to use OpenSSL.
The tls_version system variable enables specifying at startup the TLS protocols permitted by
the server. On the client side, the --tls-version option enables specifying the TLS protocols
permitted per client invocation.
The new MASTER_TLS_VERSION option for the CHANGE MASTER TO statement specifies the
encryption protocols permitted by the master for slave connections.
The mysql_options() C API function has a new MYSQL_OPT_TLS_VERSION option that enables
specifying from within the client library the TLS protocols permitted by a client program.
By default, MySQL attempts to use the highest TLS protocol version available, depending
on which SSL library was used to compile the server and client, which key size is used, and
65
MySQL 5.7 Release Notes
whether the server or client are restricted from using some protocols; for example, by means of
tls_version/--tls-version.
For more information, see Encrypted Connection Protocols and Ciphers.
Functionality Added or Changed
• InnoDB: Enabling the new innodb_background_drop_list_empty debug configuration option
helps avoid test case failures by delaying table creation until the background drop list is empty. (Bug
#21891560)
• InnoDB: The innodb_support_xa system variable, which enables support for two-phase commit
in XA transactions, is deprecated. InnoDB support for two-phase commit in XA transactions is
always enabled as of MySQL 5.7.10. Disabling innodb_support_xa is no longer permitted as it
makes replication unsafe and prevents performance gains associated with binary log group commit.
• These client programs now support the --enable-cleartext-plugin option: mysqlcheck,
mysqldump, mysqlimport, mysqlshow. This option enables the mysql_clear_password
cleartext authentication plugin. (See Client-Side Cleartext Pluggable Authentication.) (Bug
#21235226)
• These functions now produce warnings for invalid input: UNHEX(), INET_NTOA(), INET_ATON(),
INET6_NTOA(), INET6_ATON(). Also, INET_ATON() now returns NULL and produces a warning
for arguments that contain more than four groups of digits. (Bug #78856, Bug #22042027, Bug
#78884, Bug #22071558)
• MySQL distributions now include lz4_decompress and zlib_decompress utilities that can be
used to decompress mysqlpump output that was compressed using the --compress-output=LZ4
and --compress-output=ZLIB options. For more information, see lz4_decompress —
Decompress mysqlpump LZ4-Compressed Output, and zlib_decompress — Decompress
mysqlpump ZLIB-Compressed Output. (Bug #78108, Bug #21644479)
• mysql_upgrade now attempts to print more informative errors than FATAL ERROR: Upgrade
failed. (Bug #77803, Bug #21489398)
Bugs Fixed
• InnoDB; Microsoft Windows: After a crash on Windows, copying the data directory to a nonWindows platform to perform the restore caused a crash recovery failure on startup. The code did
not convert file path separators from “\” to “/” in the redo log. (Bug #21825127, Bug #78410)
• InnoDB: When attempting to create a cascading foreign key constraint on a primary key column
used in a virtual index, the error message that was returned did not include information from
dict_foreign_has_col_in_v_index(). (Bug #22050059)
• InnoDB: An in-place operation that rebuilt a table with multiple indexed virtual columns raised an
assertion. (Bug #22018532)
• InnoDB: A SELECT ... FOR UPDATE operation on a table that only contained virtual columns and
a virtual column index raised an invalid assertion. (Bug #21981164, Bug #21880930)
• InnoDB: A server exit during a TRUNCATE TABLE operation on a table with a full-text index caused
startup to fail. (Bug #21959479)
• InnoDB: An ALTER TABLE ... DISCARD TABLESPACE operation raised an invalid assertion.
(Bug #21957001, Bug #78728)
• InnoDB: Compared to previous releases, small tablespaces containing tables with BLOB values had
larger data files due to regression introduced in MySQL 5.7.5. (Bug #21950389, Bug #78623)
References: This issue is a regression of: Bug #18756233.
66
MySQL 5.7 Release Notes
• InnoDB: The ord_part flag was not reset after a failed operation to create an index on a virtual
column, causing InnoDB to assert on a subsequent insert operation. (Bug #21941320, Bug
#21979969)
• InnoDB: An invalid search tuple was created for a table with virtual columns. (Bug #21922176)
• InnoDB: InnoDB attempted to purge a virtual column index record that was not marked for deletion.
(Bug #21901389)
• InnoDB: Successive open table operations on tables with virtual columns caused a memory access
violation. (Bug #21894654)
• InnoDB: Update vector generation for a full-text search DOC_ID did not initialize a new ufield,
resulting in an assertion. (Bug #21891185)
• InnoDB: InnoDB failed to prevent foreign key SET NULL or CASCADE constraints on virtual column
base columns and virtual index columns. (Bug #21890816)
• InnoDB: An invalid comparison raised an assertion under a 64k innodb_page_size setting. (Bug
#21882024, Bug #78516)
• InnoDB: When estimating the maximum record size of a b-tree index page, InnoDB incorrectly
treated long-length fixed fields (greater than 767 bytes) as fixed-size fields instead of variable length
fields. (Bug #21880445)
• InnoDB: In debug builds, dtuple_get_n_fields attempted to read freed memory that was
previously allocated for a virtual column tuple, resulting in a server exit. (Bug #21875974)
• InnoDB: Selecting from INNODB_CMPMEM with option big-tables=1 raised a buffer pool mutex
assertion. (Bug #21871451, Bug #78494)
• InnoDB: InnoDB returned an invalid corruption-related error message during an IMPORT
TABLESPACE operation. (Bug #21838158, Bug #77321)
• InnoDB: A FLUSH TABLES ... FOR EXPORT operation asserted in
row_quiesce_table_start() when run on a partitioned table with partitions residing in a system
or general tablespace. (Bug #21796845)
• InnoDB: A DROP TABLE operation resulted in a server exit. The return value of a function call was
not checked, which lead to dereferencing of a null pointer. The patch for this bug also addresses a
potential race condition. (Bug #21794102, Bug #78336)
• InnoDB: In debug builds, an ordered scan across multiple partitions did not use a priority queue,
resulting in an assertion. (Bug #21753477)
• InnoDB: After restarting the server, the COMPRESSION column of the INNODB_SYS_TABLESPACES
table displayed incorrect data. The COMPRESSION column was removed from
INNODB_SYS_TABLESPACES. To view the current setting for page compression, use SHOW CREATE
TABLE. (Bug #21687636, Bug #78197)
• InnoDB: An invalid table flags value raised an assertion. The SYS_TABLES.MIX_LEN(flags2)
value was not read for tables that use ROW_FORMAT=REDUNDANT. (Bug #21644827)
• InnoDB: An assertion was raised when crash recovery handling of an MLOG_TRUNCATE redo log
record treated a shared tablespace as a file-per-table tablespace. Redo was skipped for the shared
tablespace. (Bug #21606676)
• InnoDB: Transaction rollback after recovery failed due to an invalid assertion. (Bug #21575121)
• InnoDB: Insufficient information in the undo log about spatial columns raised an assertion and could
result in a upgrade failure. Consequently, a slow shutdown is required prior to performing an inplace upgrade from MySQL 5.7.8 or 5.7.9 to 5.7.10 or higher. For more information, refer to Changes
Affecting Upgrades to MySQL 5.7. (Bug #21508582)
67
MySQL 5.7 Release Notes
References: This issue is a regression of: Bug #21340268.
• InnoDB: A secondary index is not permitted on a virtual column that is based on a foreign keyreferenced column that uses ON DELETE CASCADE, ON DELETE SET NULL, ON UPDATE
CASCADE, or ON UPDATE SET NULL. The restriction was not enforced. (Bug #21508402, Bug
#77843)
• InnoDB: A duplicate key error that occurred during an online DDL operation reported an incorrect
key name. (Bug #21364096, Bug #77572)
• InnoDB: An ALTER TABLE operation caused the server to exit on disk full. (Bug #21326304, Bug
#77497)
• InnoDB: The system tablespace data file did not extend automatically when reaching the file size
limit, causing startup to fail with a size mismatch error and preventing the addition of another system
tablespace data file. (Bug #21287796, Bug #77128)
• InnoDB: Altering the letter case of a column introduced an inconsistency between the frm file
and data dictionary resulting in a failed CREATE INDEX operation on the altered column. (Bug
#20755615)
• InnoDB: An ALTER TABLE operation that converted a table to an InnoDB file-per-table tablespace
did not check for unknown files with the same name as the destination .idb file, permitting an
unknown file of the same name to be overwritten. (Bug #19218794, Bug #73225)
• InnoDB: row_merge_read_clustered_index() did not handle a bulk load error correctly. (Bug
#19163625)
• Partitioning: Partition scans did not evaluate virtual generated columns properly. This could cause
issues with partitioned tables having an index on a virtual BLOB column. (Bug #21864838, Bug
#21881155)
• Partitioning: While executing CHECK TABLE, when checking whether rows were in the correct
partition, the partition engine missed updates for virtual generated columns. (Bug #21779554)
• Partitioning: Performing an in-place ALTER TABLE on a partitioned InnoDB table having one or
more partitions which used a separate tablespace could cause the server to fail. (Bug #21755994)
• Partitioning: When all partitions were pruned, they were not initialized for scanning during
initialization of indexes. This involved two related issues, one being that the active index was not set
back to the maxmimum key value when the index was closed. In addition, when this occurred as part
of a multi-range read, there were attempts to access unset variables. (Bug #78260, Bug #21754608,
Bug #21620577)
• Replication: On a multi-threaded slave configured with master_info_repository=TABLE and
relay_log_info_repository=TABLE which had previously been run with autocommit=1,
if the slave was stopped and autocommit changed to 0, executing START SLAVE caused the
session to appear to hang. After the lock wait timeout, when START SLAVE proceeded the server
would stop unexpectedly. The fix ensures that when master_info_repository=TABLE,
relay_log_info_repository=TABLE, and autocommit=0 a new transaction is generated for
start and commit to avoid deadlocks. (Bug #21440793)
• Replication: Fatal errors encountered during flushing or synchronizing the binary log
were being ignored. Such errors are now caught and handled depending on the setting of
binlog_error_action. (Bug #76795, Bug #68953, Bug #20938915, Bug #16666407)
• Microsoft Windows: Querying views on Windows could lead to memory leaks. (Bug #21908206)
References: This issue is a regression of: Bug #13901905.
68
MySQL 5.7 Release Notes
• Microsoft Windows: On Windows, the sysbench benchmark tool's "run" command would hang
when attempting to create multiple tables for the OLTP test when using shared memory connections.
(Bug #21319192, Bug #77481)
• JSON: The error message returned when trying to define a BLOB, TEXT, JSON, or GEOMETRY
column with a default value (Error 1101, ER_BLOB_CANT_HAVE_DEFAULT) referred to BLOB and
TEXT columns only. The same error applies to any of these four types when trying to use the
DEFAULT option with it in a column definition; the corresponding error message now makes this clear
by referring to JSON and GEOMETRY columns as well. (Bug #78527, Bug #21887035)
• JSON: A query using JSON_EXTRACT() returned the wrong result after a virtual index was added to
the table. (Bug #78464, Bug #21854241)
• If the server was started with --performance_schema_accounts_size=0, querying the
Performance Schema status variable tables caused a server exit. (Bug #22131713)
• For debug builds, using ALTER TABLE to add a generated column to a table could cause a
deadlock. (Bug #22083048)
• The systemd unit file did not specify any --pid-file option for mysqld, with the result that
server startup could fail. The unit file now includes a default --pid-file option in the ExecStart
value. This default can be overridden in the override.conf file by changing both PIDFile and
ExecStart to specify the PID file path name. (Bug #22066787)
• A query with nested derived tables and scalar subqueries in the select list of the derived tables might
in some cases cause a server exit. (Bug #22062023)
• When mysqld was run with --initialize, it used chown() to set the data directory owner, even
if ownership was already correct. This caused problems for AppArmor and SELinux. The server
now checks whether the data directory owner is correct and skips the chown() call if so. (Bug
#22041387)
• Failed evaluation of a generated column expression for CREATE TABLE or ALTER TABLE could
cause a server exit. Now if expression evaluation causes truncation or provides incorrect input to a
function, the statement terminates with an error and the DDL operation is rejected. (Bug #22018999)
• Creating a unique index on a virtual POINT column could result in an error or assertion for later table
accesses. (Bug #22017616)
• Sending a load spike to a newly started server could cause the Performance Schema to allocate a
large amount of memory, possibly leading to out-of-memory failure. (Bug #22006088)
• A missing error check could result in a server exit for DELETE statements that referred to userdefined variables. (Bug #21982313)
• Possible buffer overflow from incorrect use of strcpy() and sprintf() was corrected. (Bug
#21973610)
• MySQL RPM packages for RHEL5 failed to create the mysql system user. (Bug #21950975)
• MySQL does not support columns of ROW type, but the server did not prevent generated columns
from being created that used ROW expressions. These are now prohibited. (Bug #21940542)
• The version_tokens plugin called the locking service using a timeout value of only one second.
The timeout is now taken from the default value of the lock_wait_timeout system variable (that
is, one year). (Bug #21928198)
• Spatial functions could return invalid results if given a polygon or multipolygon argument containing
holes such that a hole vertex touched the exterior ring at a point lying in the interior of an
exterior ring segment. This could manifest itself as: ST_UNION() producing an invalid polygon;
ST_SymDifference() producing an invalid multipolygon; ST_Intersection() producing
an invalid self-intersecting polygon; ST_Difference() producing an invalid geometry. (Bug
#21927733, Bug #21927639, Bug #21927558, Bug #21977775)
69
MySQL 5.7 Release Notes
• With the STRICT_TRANS_TABLES SQL mode enabled, it was not possible to insert data into a
VIRTUAL generated column defined with the NOT NULL attribute. (Bug #21927469)
• Problems leading to Valgrind warnings for OpenSSL random number generation were corrected.
(Bug #21927436)
• Generated column definitions specified with the NULL attribute resulted in a syntax error. (Bug
#21900170)
• A stored procedure that used ST_Area() could return different numbers of rows for the first and
second executions. (Bug #21889842)
• For polygon values with an interior ring that touches an exterior ring, ST_Buffer() could return
invalid polygon values. (Bug #21871856)
• Two rows in the threads Performance Schema table could have the same THREAD_OS_ID value.
(Bug #21865330)
• For debug builds, using ALTER TABLE to change the expression for a generated column could
cause a server exit. (Bug #21854004)
• ALTER USER failed if the server was started with --skip-grant-tables. (Bug #21847825)
• Performance Schema reads of a session's THD structure while the session was running could create
race conditions and result in a server exit. (Bug #21841412)
• A prepared statement that computes ST_IsSimple() or ST_Buffer_Strategy() on a nullable
column in an outer join could return different numbers of rows for the first and second statement
executions. (Bug #21841051)
• Queries on the variables_by_thread Performance Schema table could cause a server exit when
examining the system variables of a new connection. (Bug #21840950)
• Spatial functions could read already freed memory. (Bug #21823135)
• For Debian package control files, libnuma-dev was added to Build-Depends to enable NUMA
support. (Bug #21822631)
• Selecting DECIMAL values into user-defined variables could cause a server exit. (Bug #21819304)
• Re-evaluation of a generated column expression could cause access to previously freed memory
and a server exit. (Bug #21810529)
• ST_SymDifference() could raise an assertion for polygons with self-intersection points. (Bug
#21767301, Bug #79031, Bug #22124757)
• USER field output from the audit log plugin was malformed. (Bug #21766380)
• A server exit could occur for queries for which a) a GROUP BY included primary key and secondary
key columns; and b) the WHERE clause included an equality predicate on the first primary key column
where that column was constant. (Bug #21761044)
• Building MySQL using parallel compilation sometimes failed with an attempt to compile
sql_yacc.yy before lex_token.h had been created. (Bug #21680733)
• With binary logging enabled, issuing DROP TEMPORARY TABLE when in XA_IDLE state caused an
assertion to be raised. Now an ER_XAER_RMFAIL error is returned.
In consquence of the fix for this issue, statements that previously succeeded in XA_IDLE state
now fail with an ER_XAER_RMFAIL error. When running with --gtid-mode=ON, an explicit DROP
continues to fail with ER_GTID_UNSAFE_CREATE_DROP_TEMPORARY_TABLE_IN_TRANSACTION.
(Bug #21638823)
70
MySQL 5.7 Release Notes
• A query with a subquery in the left-hand part of an IN subquery that was transformed into a semi-join
might cause a server exit. (Bug #21606400)
• Concurrent FLUSH PRIVILEGES and REVOKE or GRANT statements could produce a small time
window during which invalid memory access to proxy user information could occur, leading to a
server exit. (Bug #21602056)
• Using WITH ROLLUP within a subquery could cause a server exit. (Bug #21575790)
• For debug builds, a call to MAKE_SET() with a subquery as argument might be evaluated before
tables were locked, causing an assertion to be raised. (Bug #21547779)
• Starting the server with the query_alloc_block_size system variable set to certain negative
values on a machine without enough memory could result in out-of-memory errors. (Bug #21503595)
• Using UNINSTALL PLUGIN to uninstall the daemon_example plugin could cause a server exit.
(Bug #21467458)
• FLUSH DES_KEY_FILE failed to reload the DES key file. (Bug #21370329)
• If an error occurred during the setup phase of subquery materialization used to compute an
IN predicate, cleanup of the temporary table did not happen, leading to Valgrind errors. (Bug
#21346081)
• Queries rejected by MySQL Enterprise Firewall were truncated to 512 characters when written to the
error log. (Bug #20948270)
• A server exit could occur for the second execution of a prepared statement for which an ORDER BY
clause referred to a column position. (Bug #20755389)
• Repeated execution of a prepared statement could cause a server exit if the default database was
changed. (Bug #20447262)
• mysql_plugin could exit due to improper checking of string operation operands. (Bug #20376670)
• After failure to create a temporary table during join processing and releasing the table descriptor, an
attempt to access the now-invalid descriptor could cause a server exit. (Bug #19918299)
• Type conversion failure for DECIMAL values could cause a server exit. (Bug #19912326, Bug
#20013538)
• INSERT DELAYED could cause a server exit for tables partitioned with a character column as the
key and for which the expression required a character set conversion. (Bug #19894161)
• A server exit could occur when updating a view using an ALL comparison operator on a subquery
that selects from an indexed column in the main table. (Bug #19434916)
• With AddressSanitizer (ASAN) enabled, triggers that contained null or invalid characters could cause
an ASAN server exit. (Bug #18831513)
• Incorrect error checking for the NAME_CONST() function could lead to a server exit. (Bug
#17733850)
• On SELinux, mysqld --initialize with an --init-file option could fail to initialize the data
directory. Although fixed in 5.7.11, the Fedora 23 and EL6 5.7.10 RPM's were also updated with
the fix; as a *-5.7.10-2-*.rpm release to the Yum repository. (Bug #79442, Bug #22314098, Bug
#22286481)
• INSERT ... ON DUPLICATE KEY UPDATE could result in a memory leak when executed as a
prepared statement. (Bug #79122, Bug #22151233)
References: This issue is a regression of: Bug #21908206.
71
MySQL 5.7 Release Notes
• Queries that needed to store the result of ST_AsWKB() in a temporary table could fail with an error
message. (Bug #79060, Bug #22131961)
References: This issue is a regression of: Bug #21614368.
• If mysqld was started with the --help option, it created a binary log index file. If that file was
located in the data directory and the command preceded data directory initialization, initialization
then failed due to a nonempty data directory. (Bug #78986, Bug #22107047)
• Some of the source files for spatial functions in the sql directory took excessive compile time and
required too much compiler memory allocation. (Bug #78900, Bug #22078874)
• Internal buffer sizes in resolve_stack_dump were increased to accommodate larger symbol
space requirements for C++ code. (Bug #78885, Bug #22071592)
• Problems leading to Valgrind warnings for libmysqld were corrected. (Bug #78819, Bug
#22007587)
• MySQL development RPM packages could fail to install if MySQL Connector/C development RPM
packages were installed. (Bug #78815, Bug #22005375)
• mysqladmin --help displayed the old-password command, even though the command itself
was removed in MySQL 5.7.5. (Bug #78774, Bug #21972941)
• The filename character set is intended for internal use, but references to it in SQL statements did
not produce an error. Now they do. (Bug #78732, Bug #21958734)
• If a generated column used an expression that is affected by the SQL mode, the expression could
produce different results for the same input values, depending on the current SQL mode. (For
example, interpretation of the || operator depends on the PIPES_AS_CONCAT SQL mode.) Now
expression evaluation uses the SQL mode in effect at the time the column is defined. (Bug #78665,
Bug #21929967)
• Casting large hexadecimal values could produce an incorrect result and no truncation warning. (Bug
#78641, Bug #21922414)
• mysqlpump generated incorrect ALTER TABLE statements for adding foreign keys. (Bug #78593,
Bug #21907297)
• Executing HELP statements or statements involving the CONVERT_TZ() function could lead to
a memory leak and to MyISAM reference-count errors at server shutdown. (Bug #78443, Bug
#21840241)
• MySQL did not recognize functional dependencies from base columns in a generated column
expression to the generated column. (Bug #78377, Bug #21807579)
• It was possible to store non-ASCII data in columns intended to store data of character set ascii.
(Bug #78276, Bug #21774967)
• Adding a SPATIAL index to a MyISAM table could cause the cardinality of other indexes to become
incorrect. (Bug #78213, Bug #21789000)
• MySQL could fail to compile on Solaris 11.3 when /usr/gnu/bin/as was used as the linker. (Bug
#77797, Bug #21484716)
• Some punctuation characters in the armscii8 character set are represented by two encodings,
with the result that a character stored using one encoding would not be found using a search with
the other encoding. For such characters, MySQL now selects the encoding with the lowest value to
consistently map instances onto the same encoding. (Bug #77713, Bug #21441405)
• Item_copy_decimal::copy() did not take the div_precision_increment system variable
value into account, resulting in DECIMAL values being returned with incorrect precision from some
queries. (Bug #77634, Bug #21462523)
72
MySQL 5.7 Release Notes
• An aggregate function that should return NULL returned non-NULL for queries with: Implicit grouping;
an index with a string column as its first part; and a WHERE clause with an equality comparison
comparing the column to a string with trailing characters in addition to the column value, (Bug
#77480, Bug #21318711)
• LOAD_FILE() could cause a server exit for some pathnames if the character set was cp932. (Bug
#76555, Bug #20819220)
References: See also: Bug #51893.
• For constructs such as ORDER BY numeric_expr COLLATE collation_name, the character
set of the expression was treated as latin1, which resulted in an error if the collation specified
after COLLATE is incompatible with latin1. Now when a numeric expression is implicitly cast to a
character expression in the presence of COLLATE, the character set used is the one associated with
the named collation. (Bug #73858, Bug #20425399)
Changes in MySQL 5.7.9 (2015-10-21, General Availability)
• Audit Log Notes
• C API Notes
• Compilation Notes
• Packaging Notes
• Performance Schema Notes
• Plugin Notes
• Security Notes
• Spatial Data Support
• sys Schema Notes
• Functionality Added or Changed
• Bugs Fixed
Audit Log Notes
• Some events cannot be terminated. Previously, if an audit plugin returned nonzero status for a
nonterminable event, the server ignored the status and continued processing the event. However,
if an audit plugin used the my_message() function to terminate a nonterminable event, a server
exit occurred. Now the server correctly handles termination of nonterminable events using
my_message(). (Bug #21458066)
C API Notes
• Incompatible Change: The mysql_options() C API function has two new options,
MYSQL_OPT_MAX_ALLOWED_PACKET and MYSQL_OPT_NET_BUFFER_LENGTH, that set the
max_allowed_packet and net_buffer_length system variables, respectively. Each option
name also now can be passed to the mysql_get_option() C API function to retrieve its value.
For more information, see mysql_options(), and mysql_get_option().
The (undocumented) mysql_get_parameters() function has been removed. Applications
that attempt to use it will get link errors and should be modified to use mysql_options() and
mysql_get_option() instead.
One affected application is DBD::mysql, the MySQL driver for the Perl DBI. Upgrade to DBD::mysql
4.033 or higher, which includes a fix for the C API change just described. (Bug #20821550)
References: See also: Bug #20686665.
73
MySQL 5.7 Release Notes
• Previously, it was necessary to call mysql_thread_end() for each mysql_thread_init()
call to avoid a memory leak. C API internals have been reimplemented to reduce the amount of
information allocated by mysql_thread_init() that must be freed by mysql_thread_end():
• For release/production builds without debugging support enabled, mysql_thread_end() need
not be called.
• For debug builds, mysql_thread_init() allocates debugging information for the DBUG
package (see The DBUG Package). mysql_thread_end() must be called for each
mysql_thread_init() call to avoid a memory leak.
(Bug #20621281, Bug #21802367)
Compilation Notes
• Microsoft Windows: Support for building using Microsoft Visual Studio 2015 was added. Changes
include using the native (added in VS 2015) timespec library if it exists, renamed lfind/lsearch and
timezone/tzname to avoid redefinition problems, set TMPDIR to "" by default as P_tmpdir no
longer exists, deprecated std::hash_map in favor of std::unordered_map, and added Wix
Toolset 3.10 support. (Bug #21657078)
• The required version of the Boost library for server builds has been raised from 1.58.0 to 1.59.0.
(Bug #77960, Bug #21567456)
• MySQL distributions now contain a mysqlclient.pc file that provides information about MySQL
configuration for use by the pkg-config command. This enables pkg-config to be used as
an alternative to mysql_config for obtaining information such as compiler flags or link libraries
required to compile MySQL applications. For more information, see Building C API Client Programs
Using pkg-config.
A new INSTALL_PKGCONFIGDIR CMake option is available to specify the directory in which to
install the mysqlclient.pc file. The default value is INSTALL_LIBDIR/pkgconfig, unless
INSTALL_LIBDIR ends with /mysql, in which case that is removed first. (Bug #76131, Bug
#20637746)
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Packaging Notes
• The shell and Perl versions of mysql_install_db have been removed from MySQL distributions.
The executable C++ version of mysql_install_db implemented in MySQL 5.7.5 is still present,
but remains deprecated (use mysqld --initialize instead) and will be removed in a future
MySQL release. (Bug #21625471)
• The deprecated _r versions of the libmysqlclient libraries are no longer installed. (Bug
#21311067)
Performance Schema Notes
• Two changes were made regarding the effect of show_compatibility_56:
• Previously, when show_compatibility_56=OFF, selecting from the following
INFORMATION_SCHEMA system and status variable tables returned an empty result and a
deprecation warning:
INFORMATION_SCHEMA.GLOBAL_VARIABLES
INFORMATION_SCHEMA.SESSION_VARIABLES
INFORMATION_SCHEMA.GLOBAL_STATUS
74
MySQL 5.7 Release Notes
INFORMATION_SCHEMA.SESSION_STATUS
This caused confusion for applications that were not aware that such selects could be empty:
An empty result and a warning was not sufficient notice to signal the need to migrate to the
corresponding Performance Schema system and status variable tables.
To address this issue, selecting from the INFORMATION_SCHEMA system and status tables
now produces an error, to make it more evident that an application is operating under
conditions that require modification, as well as where the problem lies. The error code is
ER_FEATURE_DISABLED_SEE_DOC. The error message indicates which table is disabled and that
the show_compatibility_56 documentation should be consulted.
• Previously, when show_compatibility_56=ON, selecting from the following Performance
Schema status variable tables returned an empty result:
performance_schema.global_status
performance_schema.session_status
This made it more difficult to migrate applications from the INFORMATION_SCHEMA status
variable tables to the corresponding Performance Schema tables: Successfully selecting from the
Performance Schema tables required knowing both that the server is from MySQL 5.7 and that
show_compatibility_56=OFF.
To address this issue, selecting from the Performance Schema status variable tables now
produces the same result regardless of the value of show_compatibility_56. Thus, it is
necessary to know only that the server is from MySQL 5.7.9 or higher. (If so, select from the
Performance Schema tables. Otherwise, select from the INFORMATION_SCHEMA tables.)
For additional information about the effects of show_compatibility_56 and migration issues,
see Server System Variables, and Migrating to Performance Schema System and Status Variable
Tables. (Bug #21606701)
• These Performance Schema tables now are world readable and accessible without the SELECT
privilege: global_variables, session_variables, global_status, and session_status.
An implication of this change is that SHOW VARIABLES and SHOW STATUS no longer require
privileges on the underlying Performance Schema tables from which their output is produced when
show_compatibility_56=OFF. (Bug #21251297)
• With the show_compatibility_56 system variable enabled, the reported values of the
Last_query_cost and Last_query_partial_plans status variables were incorrect.
With the show_compatibility_56 system variable disabled, the reported values of the
Created_tmp_tables, Handler_external_lock, and Table_open_cache_% status variables
were incorrect. (Bug #20483278, Bug #21788549, Bug #21788887)
• Previously, the transaction instrument in the setup_instruments table was disabled by
default, and the events_transactions_current and events_transactions_history
consumers in the setup_consumers table were enabled by default. This setup is inconsistent, and
having the consumers enabled could lead to the impression that transactions were instrumented
by default. Now, the consumers are also disabled by default. To monitor transactions, enable the
instrument and the applicable consumers. (Bug #78311, Bug #21780891)
• With the show_compatibility_56 system variable disabled, SHOW VARIABLES and SHOW
STATUS statements failed if MySQL was compiled without Performance Schema support.
Consequently, it is no longer possible to compile without the Performance Schema. If it is desired
to compile without particular types of instrumentation, that can be done with the following CMake
options:
DISABLE_PSI_COND
DISABLE_PSI_FILE
75
MySQL 5.7 Release Notes
DISABLE_PSI_IDLE
DISABLE_PSI_MEMORY
DISABLE_PSI_METADATA
DISABLE_PSI_MUTEX
DISABLE_PSI_PS
DISABLE_PSI_RWLOCK
DISABLE_PSI_SOCKET
DISABLE_PSI_SP
DISABLE_PSI_STAGE
DISABLE_PSI_STATEMENT
DISABLE_PSI_STATEMENT_DIGEST
DISABLE_PSI_TABLE
DISABLE_PSI_THREAD
DISABLE_PSI_TRANSACTION
For example, to compile without mutex instrumentation, configure MySQL using the DDISABLE_PSI_MUTEX=1 option. (Bug #78159, Bug #21669500)
• The session_account_connect_attrs Performance Schema table had mistakenly been
changed to require the SELECT privilege. It requires no special privileges again. (Bug #77702, Bug
#21436364)
References: This issue is a regression of: Bug #14569746.
• In the setup_timers table, a CYCLE timer for ARM64 platforms is now available. (Bug #77620, Bug
#21374923)
• The Performance Schema now includes these instruments for monitoring I/O on binary log and relay
log cache files:
wait/io/file/sql/binlog_cache
wait/io/file/sql/binlog_index_cache
wait/io/file/sql/relaylog_cache
wait/io/file/sql/relaylog_index_cache
In addition, the default value of performance_schema_max_file_classes has been increased
from 50 to 80. (Bug #76225, Bug #20675180)
• The Performance Schema threads table now contains a THREAD_OS_ID column that indicates
the thread or task identifier as defined by the underlying operating system. For example, the column
value corresponds to the Process Explorer thread ID on Windows and the gettid() value on Linux.
For more information, see The threads Table.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate this change into the performance_schema database.
Plugin Notes
• The audit plugin API has been extensively revised to support a finer breakdown of the general event
type (MYSQL_AUDIT_GENERAL_CLASS) into more specific events. This enables audit plugins to
more precisely indicate the types of events in which they are interested and reduces overhead for
plugins that have use for only a few event types. The API also now permits early termination of event
execution. For more information, see Writing Audit Plugins. The general event type is still available
but is deprecated and will be removed in a future MySQL release.
In addition, a security_context plugin service is now available. Audit plugins can use this service
to examine or modify the security context of threads associated with audited events. See MySQL
Services for Plugins.
Security Notes
• For RPM-based packages, the permissions used to create the data directory (/var/lib/mysql)
have been changed from 755 to 751. This tightens the data directory permissions while still
permitting world access to the mysql.sock file in that directory. (Bug #21066592)
76
MySQL 5.7 Release Notes
• yaSSL was upgraded to version 2.3.8.
Upgrading from older versions fixes a connection-failure issue when used with the thread pool plugin.
(Bug #20774956, Bug #21888925)
Spatial Data Support
• Spatial functions such as ST_MPointFromText() and ST_GeomFromText() that accept WKTformat representations of MultiPoint values now permit individual points within values to be
surrounded by parentheses. For example, both of the following function calls are valid, whereas
previously the second one produced an error:
ST_MPointFromText('MULTIPOINT (1 1, 2 2, 3 3)')
ST_MPointFromText('MULTIPOINT ((1 1), (2 2), (3 3))')
In addition, functions such as ST_AsText() and ST_AsWKT() that produce WKT-format results
now display MultiPoint values with parentheses surrounding each point. (Bug #54065, Bug
#11761559)
sys Schema Notes
• The sys schema included in MySQL distributions was updated to version 1.5.0. This version
includes new features:
• A new diagnostics() stored procedure enables DBAs and other support personnel to collect
diagnostic information for investigating MySQL instance performance. A new metrics view and
statement_performance_analyzer() stored procedure provide supporting infrastructure for
the diagnostics() procedure.
• The following sys schema views now provide progress reporting for long-running transactions:
processlist
session
x$processlist
x$session
The progress column of these views shows the percentage of work completed for stages that
support progress reporting. For more information, see sys Schema Progress Reporting.
• sys schema objects now have a DEFINER of 'mysql.sys'@'localhost'. (Previously,
the DEFINER was 'root'@'localhost'.) Use of the reserved mysql.sys account avoids
problems that occur if a DBA renames or removes the root account.
sys schema 1.5.0 also includes fixes for several issues:
• The sys schema ps_is_instrument_default_enabled() and
ps_is_instrument_default_timed() stored functions returned incorrect results in some
cases.
• The ENABLED and HISTORY columns that were added to the setup_actors
Performance Schema table in earlier MySQL 5.7 releases caused the sys schema
ps_setup_reset_to_default() stored procedure not to work.
• Handing of event-timing information in the sys schema was updated to handle changes to
Performance Schema event-timing columns in MySQL 5.7.8.
• mysql_upgrade previously checked for an exact object-count value in the sys schema to
determine whether an upgrade was needed. If local objects had been added, the resulting
reinstallation removed those objects. Now it checks for at least the expected number of objects.
77
MySQL 5.7 Release Notes
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade to
incorporate these changes into the sys schema.
Thanks to Daniël van Eeden, Jesper Wisborg Krogh, Shlomi Noach, and Morgan Tocker for their
contributions to this update. (Bug #78115, Bug #21647101, Bug #77927, Bug #21550271, Bug
#78720, Bug #21966366)
Functionality Added or Changed
• Incompatible Change; InnoDB: To better manage redo log format changes, the redo log header of
the first redo log file (ib_logfile0) now includes a format version identifier and a text string that
identifies the MySQL version that created the redo log files.
A new boolean configuration option, innodb_log_checksums, replaces the
innodb_log_checksum_algorithm option. innodb_log_checksums=ON enables a CRC-32C
checksum, making it the only supported checksum for redo log pages.
This patch also removes unused fields from the redo log header and checkpoint pages.
Due to redo log format changes introduced by this patch, upgrading to or downgrading from MySQL
5.7.9 and higher requires a clean shutdown and, in some cases, removal of existing redo log
files. For instructions related to this change, see Changes Affecting Upgrades to MySQL 5.7, and
Changes Affecting Downgrades from MySQL 5.7. (Bug #21759424, Bug #78275, Bug #21752674)
• Important Change; InnoDB: DYNAMIC replaces COMPACT as the implicit default row format for
InnoDB tables. A new configuration option, innodb_default_row_format, specifies the default
InnoDB row format. Permitted values include DYNAMIC (the default), COMPACT, and REDUNDANT.
The COMPACT row format remained the default row format until this release to ensure compatibility
with older versions of InnoDB in MySQL 5.1 and earlier. Now that MySQL 5.1 has reached the end
of its product lifecycle, the newer DYNAMIC row format becomes the default. For information about
advantages of the DYNAMIC row format, see DYNAMIC and COMPRESSED Row Formats.
Newly created tables use the row format defined by innodb_default_row_format when a
ROW_FORMAT option is not specified explicitly or when ROW_FORMAT=DEFAULT is used.
Existing tables retain their current row format if a ROW_FORMAT option was specified explicitly. If
a ROW_FORMAT option was not specified explicitly or if ROW_FORMAT=DEFAULT was used, any
operation that rebuilds a table also silently changes the row format of the table to the format defined
by innodb_default_row_format. For more information, see Specifying the Row Format for a
Table.
• Important Change; JSON: Introduced the -> JSON column-path operator. column->path is now
supported as a synonym of JSON_EXTRACT(column, path), where column is a JSON column,
and path is a valid JSON path.
An expression with ->, like its equivalent that uses JSON_EXTRACT() instead, can be used in place
of a column identifier wherever the latter can occur within a valid SQL statement. For example, the
following CREATE TABLE and SELECT statements are valid:
CREATE TABLE t1 (
a JSON,
b INT,
g INT GENERATED ALWAYS AS (a->"$.id"),
h INT GENERATED ALWAYS AS (a->"$.storeid"),
INDEX i (g),
INDEX j (h)
);
SELECT
CONCAT(a->"$.fname", ' ', a->"$.lname") AS name,
78
MySQL 5.7 Release Notes
a->"$.id" AS id,
a->"$.storeid" AS store
FROM t1
WHERE g > 500
ORDER BY a->"$.storeid", a->"$.lname";
A column-path expression can be used for any column value that is read in a SELECT column list,
or in a WHERE, ORDER BY, or GROUP BY clause in any SQL statement; such expressions cannot be
used to set values.
When an SQL statement contains one or more expressions using -> notation, each of these is
translated into an equivalent expression that employs the JSON_EXTRACT() function instead. This
can be seen in the output from EXPLAIN when used on such a statement.
Like JSON_EXTRACT(), the -> operator returns as NULL if no matching value for an otherwise valid
path is found.
For more information about -> and JSON_EXTRACT(), see Functions That Search JSON Values.
See Searching and Modifying JSON Values, for information about JSON path support. See also
Indexing a Generated Column to Provide a JSON Column Index, for additional information and
examples.
• InnoDB: A new INNODB_METRICS server operations counter (innodb_dict_lru_count) counts
the number of tables evicted from the table cache LRU list. Thanks to Daniël van Eeden for the
patch. (Bug #21682332, Bug #78190)
• InnoDB: The new innodb_numa_interleave read-only configuration option allows you to
enable the NUMA interleave memory policy for allocation of the InnoDB buffer pool. When
innodb_numa_interleave is enabled, the NUMA memory policy is set to MPOL_INTERLEAVE for
the mysqld process. After the InnoDB buffer pool is allocated, the NUMA memory policy is set back
to MPOL_DEFAULT. This option is only available on NUMA-enabled Linux systems.
Thanks to Stewart Smith for the patch. (Bug #18871046, Bug #72811)
• JSON: The JSON value-updating functions JSON_APPEND(), JSON_SET(), JSON_REPLACE(),
and JSON_INSERT() now treat SQL NULL values as JSON null literals, which is consistent with
JSON_OBJECT() and JSON_ARRAY(). (Bug #77733, Bug #21450922)
• MySQL distributions now include these header files because my_sys.h depends on them:
my_thread_local.h, thr_cond.h, thr_mutex.h, thr_rwlock.h. (Bug #21909332)
• MySQL Server RPM packages now obsolete MySQL Connector C. Installing MySQL Server causes
older libmysqlclient from any MySQL Connector C packages to be removed and replaces them
with the current libmysqlclient. (Bug #21900800)
• RPM .spec files were updated so that MySQL Server builds from source RPM packages will include
the proper files to take advantage of operating system NUMA capabilities. This introduces a runtime
dependency on libnuma.so.1. RPM and yum detect this and refuse to install if that library is not
installed. (Bug #21775221)
• The JSON_APPEND() function was renamed to JSON_ARRAY_APPEND(). (Bug #21560934)
• The server now generates a warning when the default_storage_engine or
default_tmp_storage_engine system variable is set to a disabled storage engine named in the
disabled_storage_engines system variable. (Bug #21405865)
• Metadata locking for tablespaces has been extended so that, for DDL statements that refer to
multiple tablespaces, a metadata lock is acquired on all used tablespaces. (Bug #21376265)
• Unit testing now uses Google Mock 1.7 rather than 1.6. (Bug #21215389)
• Support for building with Solaris Studio 5.13 was added. (Bug #21185883)
79
MySQL 5.7 Release Notes
• mysql_ssl_rsa_setup now is less noisy by default. Output from openssl commands is
displayed only if --verbose is given. (Bug #21024979)
• Insert overhead for the MEMORY storage table was reduced by caching computed hash values. (Bug
#78480, Bug #21866029)
• The initial-password message written by mysqld --initialize to the error log has been reduced
from a [Warning] to a [Note]. (Bug #78182, Bug #21680457)
• mysqlpump now supports a --version option. (Bug #77894, Bug #21534277)
• Unneeded scripts and test files were removed from the tests directory and that directory was
renamed to testclients. (Bug #77807, Bug #21490075)
• Performance Schema digests in DIGEST_TEXT columns have ... appended to the end to indicate
when statements exceed the maximum statement size and were truncated. This is also now done for
statement text values in SQL_TEXT columns. (Bug #75861, Bug #20519832)
• Output from mysql_upgrade is now less noisy and more informative. (Bug #59077, Bug
#11766046)
• A new SHUTDOWN SQL statement is available. This provides an SQL-level interface to the
same functionality previously available using the mysqladmin shutdown command or the
mysql_shutdown() C API function. See SHUTDOWN Syntax.
The mysql_shutdown() function and corresponding COM_SHUTDOWN client/server protocol
command are deprecated and will be removed in a future version of MySQL. Instead, use
mysql_query() to execute a SHUTDOWN statement.
Bugs Fixed
• Important Change; InnoDB; Partitioning: There was no way to upgrade existing partitioned tables
to use the native partitioning implemented for InnoDB tables in MySQL 5.7.6. This fix adds support
to both mysql_upgrade and the mysql client for upgrading partitioned InnoDB tables created
in previous releases, which used the ha_partition handler, to use InnoDB native partitioning
instead.
• mysql_upgrade now checks for all InnoDB tables that were created using the generic
ha_partition handler and attempts to upgrade them to InnoDB native partitioning.
• In the mysql client, pre-5.7.6 partitioned InnoDB tables can be upgraded one by one to
native partitioning using the ALTER TABLE ... UPGRADE PARTITIONING statement that is
implemented in this release.
(Bug #20727344, Bug #76374)
• Important Change; Replication: The START SLAVE and STOP SLAVE statements can no longer
be used for the group_replication_recovery channel. See Replication Channels, for more
information. (Bug #21680074)
• Important Change; Replication: In MySQL 5.7, the binlog_max_flush_queue_time system
variable introduced in MySQL 5.6 no longer has any effect. This variable is now deprecated, and has
been marked for eventual removal in a future MySQL release. (Bug #21347087)
• Important Change; Replication: When using a single-threaded slave, the status of the
applier thread is now reported as part of the replication_applier_status_by_worker
table, instead of replication_applier_status_by_coordinator. This means that
replication_applier_status_by_coordinator is now empty when using a single-threaded
slave; it should be noted that such reporting for multi-threaded slaves has not been changed, and
continues to be shown in that table. (Bug #74765, Bug #20001173)
• InnoDB; Microsoft Windows: Attempting to create a general tablespace data file on a Windows
root drive caused an error. (Bug #21419888, Bug #77676)
80
MySQL 5.7 Release Notes
• InnoDB; Microsoft Windows: Setting lower_case_table_names=0 on a case-insensitive file
system could result in a hang condition when running an INSERT INTO ... SELECT ... FROM
tbl_name operation with the wrong tbl_name letter case. An error message is now printed and the
server exits when attempting to start the server with --lower_case_table_names=0 on a caseinsensitive file system. (Bug #20198490, Bug #75185)
• InnoDB: The undo log contained insufficient information about virtual columns and virtual column
indexes, which could cause a server exit when adding or dropping virtual columns. As a result, a
slow shutdown (using innodb_fast_shutdown=0) is required prior to performing an in-place
upgrade or downgrade from MySQL 5.7.8. For more information, refer to Upgrading or Downgrading
MySQL. (Bug #21869656, Bug #78489)
• InnoDB: A table-rebuilding ALTER TABLE operation that created an index on a virtual column raised
an assertion. (Bug #21847170, Bug #78452)
• InnoDB: A SELECT ... FOR UPDATE operation on a table with virtual generated columns raised
an assertion. InnoDB unnecessarily retrieved a non-indexed virtual column for a covered secondary
index scan. (Bug #21827963)
• InnoDB: Creating a table with large rows failed when using a ROW_FORMAT=DYNAMIC or
ROW_FORMAT=COMPRESSED due to an incorrect undo log record size calculation. The same
operation succeeded with ROW_FORMAT=COMPACT or ROW_FORMAT=REDUNDANT.
ROW_FORMAT=DYNAMIC and ROW_FORMAT=COMPRESSED now permit a row length violation at DDL
time if innodb_strict_mode is disabled. (Bug #21816041, Bug #78392)
• InnoDB: Adding an index on a virtual generated column with an index prefix length that exceeded
the maximum length caused a server exit. (Bug #21812026)
• InnoDB: A memory leak occurred after crash recovery. Memory allocated in
fil_space_read_name_and_filepath() was not freed. (Bug #21811321)
• InnoDB: Altering the data type or computation method of a virtual generated column caused an
error. (Bug #21810004)
• InnoDB: An assertion was raised when creating a spatial index. InnoDB failed to count virtual
columns that preceded the spatial index column. (Bug #21807340)
• InnoDB: Tablespace discovery modifications in MySQL 5.7.5 included the removal of code related
to MLOG_FILE_CREATE2 redo log records. As a result, the redo log did not contain sufficient
information about file creation. (Bug #21801423, Bug #78363)
• InnoDB: The redo log provided no indication that redo logging is disabled for index page writes
during concurrent DDL operations. As a result, external hot backup tools could produce corrupt
backups. (Bug #21796691, Bug #78351)
• InnoDB: In debug builds, recovery asserted during a transparent page compression test. A torn
page from the doublewrite buffer caused an LSN debug check failure. (Bug #21796092)
• InnoDB: Creating a virtual generated column on a partitioned table caused a server exit. (Bug
#21790751, Bug #78326)
• InnoDB: An old version of numactl headers on the build host caused a compilation error when
building a MySQL version that includes NUMA memory policy support. (Bug #21785074)
• InnoDB: A SELECT .. FOR UPDATE operation on an indexed virtual generated column raised an
assertion. (Bug #21775459)
• InnoDB: The tablespace identifier (space_id) was logged twice for an MLOG_TRUNCATE redo log
record. (Bug #21744589)
• InnoDB: Crash recovery issued an invalid error message indicating that an isl file could not be
opened or is not correct. (Bug #21691438)
81
MySQL 5.7 Release Notes
• InnoDB: The InnoDB Monitor displayed incorrect mutex creation information for a mutex with a long
semaphore wait. (Bug #21682997, Bug #78179)
• InnoDB: Error message formatting was corrected in the os_file_write_page() function. (Bug
#21681433, Bug #78184)
• InnoDB: The i_s_dict_fill_sys_tablespaces() function could free memory associated with
a file name before printing an error message. (Bug #21680518, Bug #78180)
• InnoDB: In debug builds, scanned and applied redo log records are now printed with a string
identifier instead of a numerical identifier when --debug=d,ib_log is passed to mysqld. For
example, rec MLOG_2BYTES is now printed instead of rec 2. (Bug #21664268, Bug #78148)
• InnoDB: The number of system calls made by the InnoDB page compression feature was reduced.
(Bug #21654695)
• InnoDB: The recv_parse_log_rec function returned the length of the redo log record instead of 0
when encountering an incomplete MLOG_CHECKPOINT record. (Bug #21640085, Bug #78058)
References: This issue is a regression of: Bug #17798076.
• InnoDB: In debug builds, a parenthesis mismatch in a MATCH() ... AGAINST clause raised a fulltext parser assertion. (Bug #21638907)
• InnoDB: Debug code was added to avoid a doublewrite buffer assertion that was raised during
Valgrind testing. (Bug #21631197)
• InnoDB: Log messages were improved to help identify out-of-space errors that could occur when
adding rollback segments. (Bug #21629618)
• InnoDB: In debug builds, enabling the innodb_log_checkpoint_now debug option while a tablerebuilding ALTER TABLE operation is running could result in an infinite loop. (Bug #21628087, Bug
#78056)
• InnoDB: UNIV_INLINE was not defined for the dict_table_has_indexed_v_cols function.
(Bug #21628058, Bug #78055)
• InnoDB: Altering a virtual column data type is not supported as an in-place operation. (Bug
#21617377)
• InnoDB: Sorting was skipped by an ALTER TABLE statement that changed the primary key and
dropped the last column of the previous primary key. (Bug #21612714, Bug #78020)
• InnoDB: During recovery, an invalid isl file was treated as a missing isl file, resulting in the
tablespace being opened using the file location defined in an MLOG_FILE_* record in the redo log.
Recovery no longer opens the tablespace if the isl file is invalid. (Bug #21577278, Bug #77986)
• InnoDB: Code that provided a timeout mechanism intended to reduce adaptive hash index search
latch (btr_search_latch) contention was removed. The code became obsolete after the
introduction of adaptive hash index search system partitioning in MySQL 5.7.8. (Bug #21569876,
Bug #77957)
• InnoDB: The COMPRESSION option was displayed incorrectly in SHOW CREATE TABLE output. (Bug
#21557723, Bug #77940)
• InnoDB: An innodb_data_file_path mismatch raised an assertion, as did initializing the
database with a data file size that was too small for the specified page size. (Bug #21551464)
• InnoDB: A check was added to prevent accessing full-text index tables that are in an inconsistent
state. (Bug #21529012)
• InnoDB: A schema mismatch error occurred when importing a tablespace that was altered by DROP
INDEX operation on the source server. (Bug #21514135, Bug #77659)
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MySQL 5.7 Release Notes
• InnoDB: Creating an index on a virtual generated column after adding a full-text index on a
preceding column raised an assertion. (Bug #21478389)
• InnoDB: For tables with a DYNAMIC or COMPRESSED row format, more data than necessary was
undo logged for virtual columns. (Bug #21477535)
• InnoDB: An INSERT operation raised a btr_search_enabled assertion. Assertion code was too
restrictive. (Bug #21457373)
• InnoDB: Reloading a table that was evicted while empty caused an AUTO_INCREMENT value to be
reset. (Bug #21454472, Bug #77743)
• InnoDB: A crash during a TRUNCATE TABLE operation caused the server to exit on startup. (Bug
#21451922)
• InnoDB: The .isl was not removed when dropping a general tablespace that was created outside
of the MySQL data directory. (Bug #21446772, Bug #77724)
• InnoDB: An inconsistent read occurred under the REPEATABLE READ transaction isolation level.
Transactions that operated on the same row were removed from transaction ID list in the incorrect
order. (Bug #21433768, Bug #77699)
References: This issue is a regression of: Bug #17320977.
• InnoDB: After disabling the adaptive hash index feature, an adaptive hash index latch was
unnecessarily obtained and released. (Bug #21407023)
• InnoDB: An ALTER TABLE operation on a table with an index defined on a virtual column incorrectly
modified the data of the virtual column. (Bug #21376546, Bug #77628)
• InnoDB: A virtual column-related purge operation raised an assertion. (Bug #21374258)
• InnoDB: On a partitioned table, creating an index on a generated column raised an assertion. (Bug
#21372331)
• InnoDB: Resizing the buffer pool online raised an assertion due to a memory full condition. (Bug
#21348684, Bug #77564)
• InnoDB: An ALTER TABLE ... IMPORT TABLESPACE operation with innodb_page_size=4K
and ROW_FORMAT=DYNAMIC raised an assertion. (Bug #21341030, Bug #77540)
• InnoDB: For spatial indexes, InnoDB unnecessarily stored a 3072-byte prefix in undo log records
instead of just the maximum bounding rectangle (MBR). For columns with externally stored data,
both the prefix and MBR are logged. (Bug #21340268, Bug #77537)
• InnoDB: Invalid init_ftfuncs() assertion code was removed. (Bug #21300774)
• InnoDB: Memory allocation sanity checks were added to the memcached code. (Bug #21288106)
• InnoDB: An incorrect reference count caused a hang in the TrxInInnoDB constructor.
innobase_close_connection() released the transaction object before destroying the
TrxInInnoDB object where the reference count is adjusted. (Bug #21280816)
• InnoDB: A MySQL 5.7.8 patch that reintroduced SHOW ENGINE INNODB MUTEX functionality
caused a performance regression. (Bug #21266784)
References: See also: Bug #77314, Bug #21238953.
• InnoDB: A memcached flush_all command raised an assertion. A function that starts a
transaction was called from within assertion code. (Bug #21239299, Bug #75199)
• InnoDB: A shutdown hang occurred when a high priority transaction waited for a victim transaction
to exit while the victim transaction waited for an asynchronous rollback to complete. (Bug
#21143276)
83
MySQL 5.7 Release Notes
• InnoDB: A data corruption occurred on ARM64. GCC builtins did not issue the correct fences when
setting or unsetting the lock word. (Bug #21102971, Bug #76135)
• InnoDB: Server shutdown was delayed waiting for the purge thread to exit. To avoid this problem,
the number of calls to trx_purge() was reduced, and the trx_purge() batch size was reduced
to 20. (Bug #21040050)
• InnoDB: In READ COMMITTED mode, a REPLACE operation on a unique secondary index resulted in
a constraint violation. Thanks to Alexey Kopytov for the patch. (Bug #21025880, Bug #76927)
• InnoDB: The IBUF_BITMAP_FREE bit indicated that there was more free space in the leaf page
than was actually available. (Bug #20796566)
• InnoDB: Moving the data directory before recovering a crashed database caused tablespace
discovery to fail for file-per-table tablespaces created outside of the MySQL data directory. (Bug
#20698468, Bug #76308)
• InnoDB: The innodb_buf_flush_list_now debug setting failed to flush all dirty pages to disk.
(Bug #20582189)
• InnoDB: An ALTER TABLE ... ADD FULLTEXT INDEX operation raised an assertion. A thread
attempted to use a lower priority transaction that was being rolled back before the rollback operation
completed. (Bug #20481175)
• InnoDB: Running an ALTER TABLE operation on a referencing table with a cascading foreign key
constraint during a concurrent DML operation on the referenced table caused a loss of referential
integrity. (Bug #20367116)
• InnoDB: The server failed to start with an innodb_force_recovery setting greater than 3.
InnoDB was set to read-only mode before redo logs were applied.
DROP TABLE is now supported with an innodb_force_recovery setting greater than 3. (Bug
#19779113)
• InnoDB: The trx_sys_read_pertable_file_format_id() function reported the wrong file
format. (Bug #19206671)
• InnoDB: The mysql_system_tables_fix_for_downgrade.sql script, provided to facilitate
system table alterations when downgrading from MySQL 5.7.6 or higher, was removed from the
MySQL installation directory. The script was no longer valid for all downgrade paths. For more
information, see Changes Affecting Downgrades from MySQL 5.7. (Bug #78259, Bug #21753832)
• InnoDB: A virtual generated column on a table that uses index condition pushdown (ICP) caused an
assertion. (Bug #77842, Bug #21507796, Bug #21478287)
• Packaging; OS X: Using user=mysql during installation on OS X did not allow the mysql
database to be installed. To fix this problem, OS X packages now use the --no-defaults option
when creating this database. This also means that having a my.cnf file on the system no longer
affects the installation. (Bug #21364902)
• Partitioning: Error handling for failed partitioning-related ALTER TABLE operations against nonpartitioned tables was not performed correctly (Bug #20284744)
• Partitioning: ALTER TABLE when executed from a stored procedure did not always work correctly
with tables partitioned by RANGE. (Bug #77333, Bug #16613004, Bug #21246891)
• Replication: The group replication applier channel does not support DATABASE as the
slave_parallel_type; when group replication is started, this is checked for explicitly,
and handled correctly. However, it remained possible to change this value indirectly at a later
point in time by increasing the value of slave_parallel_workers while the slave SQL
thread was stopped, which caused the applier to fail with an error. To fix this problem, the
slave_parallel_type for the group_replication_applier is now checked to make sure
84
MySQL 5.7 Release Notes
that it is set to LOGICAL_CLOCK whenever the number of slave_parallel_workers is set
greater then 0, and not merely when group replication is first started. (Bug #21798804)
• Replication: As binlog_error_action=ABORT_SERVER is the default in MySQL 5.7.7 and later
it is being used for more error situations. The behavior has been adjusted to generate a core dump to
improve troubleshooting possibilities. (Bug #21486161, Bug #77738)
• Replication: At runtime, some Gtid_set objects could be instrumented with a Performance
Schema mutex key equal to 0 (which is invalid), due to its use as the effective default value when the
mutex key was not actually supplied. This allowed these objects to be created without a valid key,
which led to further issues when using them. (Bug #21485997)
• Replication: When running the server with gtid_mode=ON, a DELETE from a MEMORY table
following a restart was not written to the binary log correctly. (Bug #21045848)
• Replication: The locking behavior of replication administration statements has changed to make
SHOW SLAVE STATUS more concurrent. This makes the NONBLOCKING clause redundant for SHOW
SLAVE STATUS and it has been removed. (Bug #20593028)
• Replication: ER_CANT_USE_AUTO_POSITION_WITH_GTID_MODE_OFF errors were not reported
using the correct format. (Bug #20545943)
• Replication: When the dump thread was killed while dumping an inactive binary log, some events in
this log could be skipped and thus not replicated. (Bug #78337, Bug #21816399)
References: See also: Bug #74607, Bug #19975697.
• Replication: XA transactions could cause an assert condition on XA COMMIT; this was happening
because the internal transaction state was not reset between XA PREPARE and XA COMMIT or
XA ROLLBACK, due to the fact that these operations constitute separate transactions under XA. In
addition, XA ROLLBACK statements were not handled properly in some cases. (Bug #78264, Bug
#21755890)
• Replication: The interface between the Group Replication plugin and the Performance Schema
engine made use of a type of memory allocation which was passed to the server, and was a potential
source of problems when passing information between the plugin and performance_schema
tables. The implementation for this interface has been reworked so as to avoid performing this type
of memory allocation when sharing data. (Bug #78263, Bug #21755699)
• Replication: The MTS submode set for each channel was ignored by the worker threads, which
continued to read and use the global flag set for all slave channels. This could lead to errors when
the coordinator was of one type and its workers of another. (Bug #77763, Bug #21464737)
• Replication: Replication slaves could fail for having insufficient privileges when they had been
granted only the REPLICATION SLAVE privilege. (Bug #77732, Bug #21455603)
• Replication: The status variable Slave_open_temp_tables keeps track of the number of
temporary tables that are opened by the replication slave. If multi-source replication is enabled, it is
the total number of temporary tables for all channels. This fix addresses the following issues relating
to this variable:
• RESET SLAVE FOR CHANNEL channel forced the value of Slave_open_temp_tables
to 0; in the event that some other replication channel had open temporary tables which were
later dropped, the value wrapped around to a large negative value (1 - 232). This also caused
spurious or missed warnings when issuing a STOP SLAVE or CHANGE MASTER TO statement.
• The internal function that modifies Slave_open_temp_tables in such cases relied on two
incorrect assumptions:
1. That the variable is updated by only one thread when multi-threaded slaves are not enabled,
which is not true in the case of multi-source replication.
85
MySQL 5.7 Release Notes
That non-atomic operations are safe with a single writer and multiple readers, which is not
necessarily true for some platforms supported by MySQL.
(Bug #77585, Bug #21357008)
• Replication: The warning '@@session.gtid_executed' is deprecated and will
be removed in a future release. was printed even when the session variable
gtid_executed was not included in the result of a query. In addition, the result of SELECT
@@session.gtid_executed included a duplicate warning. Both issues occurred because the
warning was printed whenever the value of gtid_executed was accessed by a statement, such
access occurring as a matter of course, whether or not a given variable is actually included in the
result.
To fix this issue, we make handling of @@session.gtid_executed consistent with how the alsodeprecated variable @@global.sql_log_bin is treated in such cases, by making the following
changes:
• gtid_executed is no longer included in the performance_schema.session_variables
table.
• gtid_executed is still included in the information_schema.session_variables table,
but when show_compatibility_56 = ON, the warning is not issued when querying the
session_variables table, or when issuing SHOW VARIABLES or SHOW SESSION VARIABLES,
even when using a matching LIKE clause with either of the SHOW statements.
The warning is still issued by a statement such as SELECT @@session.gtid_executed which
accesses the value of the variable directly. (Bug #77574, Bug #21354712)
References: See also: Bug #75980, Bug #20575529, Bug #76626, Bug #20854952.
• Replication: When a transaction consisting of a single statement with a specified GTID failed in
autocommit mode, its GTID was not released when rolling it back when binary logging was disabled.
(Bug #77521, Bug #21338147)
• Replication: The slave group event parser did not properly register an XA_ROLLBACK event as a
transaction boundary. (Bug #77392, Bug #21273010)
References: See also: Bug #20920851.
• Replication: mysqlbinlog printed a ROLLBACK statement at the end of the binary log
file, which when played back failed with error 1782 @@SESSION.GTID_NEXT cannot
be set to ANONYMOUS when @@GLOBAL.GTID_MODE = ON. This occurred when the
binary log file did not include any data related events, or when the relay log file included a
Format_description_log_event that had been generated on the master at server startup.
The fix for this issue causes a relay log's Format_description_log_event to do nothing if it is
applied by a BINLOG statement, and stops a ROLLBACK from setting gtid_next to ANONYMOUS
when the state of gtid_next has not yet been determined by a subsequent event. (Bug #76887,
Bug #20980932)
• Replication: SAVEPOINT and ROLLBACK TO SAVEPOINT within a trigger led to an assertion. (Bug
#76727, Bug #20901025)
• Replication: While a SHOW BINLOG EVENTS statement was executing, any parallel transaction was
blocked. The fix ensures that the SHOW BINLOG EVENTS process now only acquires a lock for the
duration of calculating the file's end position, therefore parallel transactions are not blocked for long
durations. (Bug #76618, Bug #20928790)
• Replication: If a CREATE VIEW statement failed, it was being incorrectly written to the binary log
even though it did not result in the creation of a partial view. The fix ensures that such statements are
86
MySQL 5.7 Release Notes
not recorded in the binary log. Additionally it was found that when a statement which had failed on a
master was received by a slave with an expected error, if the statement was skipped on the slave,
for example due to a replication filter, the expected error was being compared with the actual error
that happened on the slave. The fix ensures that if a statement with an expected error is received
by a slave, if the statement has not been filtered, only then is it compared with the actual error that
happened on the slave. (Bug #76493, Bug #20797764)
• Replication: The action specified for binlog_error_action was not always honored correctly
after a hardware failure occurred during log rotation. (Bug #76379, Bug #20805298)
• Replication: When using MySQL 5.7.6 and later with binlog_format=row and gtid_mode=off,
if CREATE ... SELECT was killed during execution it could lead to an inconsistent state, breaking
replication. The cause was that in MySQL 5.7.6 the way CREATE ... SELECT was logged was
changed, so that a commit was introduced between the CREATE TABLE and SELECT steps. The
fix ensures that CREATE ... SELECT does not commit in the middle of the transaction when
binlog_format=row. (Bug #76320, Bug #77098, Bug #20742519, Bug #21114464)
• Replication: Modifying the master_info_repository or relay_log_info_repository
inside a transaction and later rolling back that transaction left the repository in an unusable state. We
fix this by preventing any modification of these repositories inside a transaction. (Bug #74950, Bug
#20074353)
• Replication: Transactions added to gtid_executed using SET gtid_purged were not taken into
account by WAIT_FOR_EXECUTED_GTID_SET() until a subsequent transaction was committed by a
client or slave thread. (Bug #73838, Bug #19579811)
• Replication: When using --relay-log-info-repository=TABLE, the
mysql.slave_relay_log_info table is updated when a transaction is committed or when
a flush is performed explicitly, such as during relay log rotation. If a transaction that uses any
nontransactional tables (for example MyISAM tables) is split across multiple relay logs, it is partially
committed on relay log flush. When gtid_mode=ON, this caused the same GTID to be used for the
remaining portion of the transaction, which raised an ER_GTID_NEXT_TYPE_UNDEFINED_GROUP
error.
We fix this issue by postponing in such cases the update of the relay log information repository
that normally occurs on relay log rotation until the commit for the transaction in question has been
executed.
This issue did not affect tables using transactional storage engines such as InnoDB. (Bug #68525,
Bug #16418100)
References: See also: Bug #21630907, Bug #76974.
• JSON: Although the use of JSON values with GREATEST() or LEAST() is not currently supported,
the server did not handle attempts to do so correctly, leading to an assert (Linux) or exit() call
(Windows) in debug builds. Now when you try to use JSON values with either of these functions, the
server emits a suitable warning (ER_NOT_SUPPORTED_YET). (Bug #21828321)
References: See also: Bug #21383497.
• JSON: A table that included a generated column referencing a JSON column in some cases become
corrupted, so that a subsequent access of the table using a different connection caused the server to
fail. (Bug #21808680)
References: See also: Bug #21824519, Bug #78408.
• JSON: JSON_TYPE() returned OPAQUE for some binary values that it should have identified as
BLOB. (Bug #21649073)
• JSON: JSON functions could return incorrect values if a path argument was passed as a userdefined variable that changed values between result set rows. (Bug #21602361)
87
MySQL 5.7 Release Notes
• JSON: If a multiple-column UPDATE statement failed to update a JSON column that was then
referenced in a later update, the server could exit. (Bug #21547877)
• JSON: For debug builds, incorrect caching of JSON values could cause an assertion to be raised.
(Bug #21491442)
• JSON: An empty string (which is not a valid JSON value) normally is parsed and returned as a JSON
null literal, but in some cases could raise an assertion for debug builds. (Bug #21487833)
• JSON: When a view was the inner table of an outer join, a JSON column could produce a non-NULL
value when NULL was expected. (Bug #21448719)
• JSON: If JSON_CONTAINS_PATH() was called with a one_or_all argument of all and a path
argument contained a wildcard, the function found all matches per path, even though in this case one
match is sufficient. (Bug #21442775)
• JSON: JSON_SET() and JSON_REPLACE() sometimes produced an incorrect result if a path
expression identified a nonarray value. (Bug #21442624)
• JSON: Suppression of JSON conversion errors using non-strict SQL mode or INSERT IGNORE
could then cause an assertion to be raised if an empty value inserted into a JSON NOT NULL
column was copied to another JSON column. (Bug #21437989)
• JSON: For deeply nested JSON input, ST_GeomFromGeoJSON() or JSON_VALID() could produce
stack overflow. (Bug #21389101, Bug #21377136)
• JSON: Failure to parse a JSON string that contained a floating-point number with a large, negative
exponent could cause a server exit. (Bug #21384048)
• JSON: For debug builds, invoking ST_AsGeoJSON() within GROUP BY ... WITH ROLLUP could
raise an assertion. (Bug #21383497)
• JSON: JSON_SEARCH() could return incorrect results if an invalid escape expression was specified.
(Bug #21383284)
• JSON: For debug builds, a NULL first argument to JSON_SET() could raise an assertion. (Bug
#21381806)
• JSON: For expressions of the form (subquery) IN (subquery), where a subquery could return
a JSON value, failure to handle a row result could cause a server exit.` (Bug #21376088)
• JSON: Failure of JSON_APPEND() to handle a legal condition could cause a server exit. (Bug
#21373874)
• JSON: Certain JSON functions could return incorrect results when used in prepared statements
which had path expression constants. (Bug #77785, Bug #21472872)
• RHEL RPM packages had incorrect dependency information. (Bug #22218841)
• For an index-only scan over an indexed generated column, the server could do random calculations;
the random results were not exposed to the user, but Valgrind warnings could occur, and the server
could exit when calculations involved functions which did not expect such incorrect data. (Bug
#21833760)
• For tables with VIRTUAL generated columns, an INSERT with an empty values list could cause a
server exit. (Bug #21807818)
• CMake configuration was adjusted to handle new warnings reported by Clang 3.7. (Bug #21803314)
• For plugins of type PROTOCOL_PLUGIN, execution of INSTALL PLUGIN, UNINSTALL PLUGIN,
or SHUTDOWN could cause a server exit. Such plugins are no longer permitted to execute these
statements. (Bug #21797816)
88
MySQL 5.7 Release Notes
• Using a materialized view defined over a table containing generated columns could cause a server
exit. (Bug #21797776)
• For partitioned InnoDB tables containing a virtual generated column, reads from the table could
return random data for the column. (Bug #21779011)
• The CMake checks for NUMA availability could cause compilation problems on platforms without
NUMA support. (Bug #21774859)
• The optimizer did not consider nonfunctional expressions such as (a AND b) = 1 when looking for
indexed generated columns to substitute for the (a AND b) expression. Now expressions using the
AND and OR logical operators are considered. (Bug #21770798)
• For debug builds, when the optimizer tried to clone certain types of keys for a range optimization, an
assertion was raised. (Bug #21761867)
• For debug builds, the server could exit when the optimizer attempted to estimate the cost for
processing unique values when there were no keys. (Bug #21697002)
• An INSERT into a view with a subquery could fail if executed as a prepared statement. (Bug
#21696206)
• For queries on InnoDB tables for which the optimizer used SPATIAL indexes for full index scans,
the result was empty because such indexes do not support a full scan. The optimizer no longer
considers SPATIAL indexes as candidates for full index scans. (Bug #21663612)
• For some inputs, ST_Intersection() could return an invalid polygon. (Bug #21658453)
• Spatial functions could simplify geometry values in contexts where the value might be used
elsewhere in a query, producing incorrect results. (Bug #21652012)
• If ST_ConvexHull() or ST_SRID() were used in a view definition, the resulting definition
contained ST_Convex_Hull() (misspelled) or SRID() (deprecated). (Bug #21651588)
• For debug builds, enabling the PAD_CHAR_TO_FULL_LENGTH SQL mode could cause SHOW
FUNCTION STATUS to raise an assertion. (Bug #21632425)
• mysqlpump did not exit with a message for some combinations of incompatible options. (Bug
#21628662)
• An assertion could be raised if the optimizer tried to create a temporary table based on a prepared
statement parameter. (Bug #21625929)
• Executing a prepared statement with multiple nested subqueries could raise an assertion. (Bug
#21624851)
• For debug builds, failure of subquery optimization could cause an assertion to be raised due to
improper error handling. (Bug #21621313)
• Some table and index optimizer hints were lost early in statement processing, so query rewrite
plugins did not have access to them. This could cause incorrect matching between incoming
statements and statement pattern templates. (Bug #21619780)
• Queries containing nested subqueries combining grouping and outer references might cause a
server exit. (Bug #21619634)
• Passing NULL as the second or third argument to ST_AsGeoJSON() could cause the server to stop
responding to the session or (in debug builds) to raise an assertion.
Giving input to HANDLER READ that could not be converted to the correct type could cause the
server to stop responding to the session or (in debug builds) to raise an assertion. (Bug #21616810,
Bug #21650603)
89
MySQL 5.7 Release Notes
• For debug builds, ST_IsValid(NULL) could raise an assertion. (Bug #21616647)
• For debug builds, an assertion could be raised for negative zero values when converting time values
to decimal. (Bug #21616585)
• ST_AsWKB() could cause a server exit if given invalid data. (Bug #21614368)
References: See also: Bug #22131961.
• If an aggregate function was used over a generated column that was itself part of a multiple-column
index, the server could exit. (Bug #21613615)
• A missing error check during column reference resolution could result in an incorrect error message
or (in debug builds) an assertion being raised. (Bug #21613422)
• For debug builds, an assertion could be raised in Filesort::make_sortorder() for attempts to
sort Item_ref objects. (Bug #21611270)
• For debug builds, an assertion was raised for some queries that have a semi-join and use the
materialization strategy, if a key length or number of key parts was zero. (Bug #21566735)
• Compilation using gcc 4.9 or 5.1 failed on ARM64 platforms. (Bug #21552524)
References: See also: Bug #21845828.
• For debug builds, invalid geometry byte strings could cause spatial functions to raise an assertion
rather than return an error to the caller. (Bug #21546656)
• For debug builds, a too-strict assertion could be raised by invalid characters for LOAD DATA. (Bug
#21542698)
• The server could exit when InnoDB tried to update a secondary index on a VIRTUAL generated
column of type BLOB. (Bug #21530366)
• For temporary tables created to handle UNION statements that selected CHAR or SET columns, the
maximum column width could be too long for InnoDB to handle. Now such columns are created as
variable-length columns. (Bug #21480999)
• For builds configured with MAX_INDEXES greater than 64, certain queries for which the server used
temporary tables could cause a server exit. (Bug #21466850)
• Adding or dropping a VIRTUAL generated column could cause a server exit. (Bug #21465626)
• For plugins that use the audit plugin API, MYSQL_AUDIT_GLOBAL_VARIABLE_SET events passed to
the notification function did not include the new variable value. (Bug #21457699)
• Queries on a table containing an indexed generated column could fail if the table name contained
special characters. (Bug #21454155)
• For debug builds, some spatial functions that accept raw byte data for spatial arguments (for
example, specified as hex values) could raise an assertion if such an argument contained extra
garbage following valid data. (Bug #21397107)
• For debug builds, an incorrect assertion could be raised during subquery execution. (Bug
#21383882)
• For debug builds, a missing error check in Item_sum_hybrid::fix_fields() caused an
assertion to be raised. (Bug #21383714)
• Calls to ST_Buffer() could hang or raise an assertion. (Bug #21372946)
• The server could exit in unclean fashion if configured to listen on a TCP/IP port number already in
use by another server instance. (Bug #21368299)
90
MySQL 5.7 Release Notes
• Certain subqueries as arguments to PROCEDURE ANALYSE() could cause a server exit. (Bug
#21350175)
• A query with a right outer join inside a derived table might return wrong data. (Bug #21350125)
• Starting the server with --skip-grant-tables (or with options such as --initialize for which
--skip-grant-tables is implicit) prevented the INSTALL PLUGIN and UNINSTALL PLUGIN
statements from working. (Bug #21335821)
• mysql_ssl_rsa_setup could create an unwanted .rnd file in the data directory. (The file is
actually created by openssl, which mysql_ssl_ras_setup invokes. mysql_ssl_rsa_setup
now cleans up the file.) (Bug #21335818)
• Some INFORMATION_SCHEMA queries consumed excessive memory due to suboptimal query plans
and insufficient materialization. (Bug #21299665)
• With the server configured to send error messages to syslog or a log file, messages generated
prior to error log setup were sent to stderr or stdout. These messages are now buffered until
error log setup has completed, then logged to the proper destination. (Bug #21296553)
• Executing a prepared statement using a derived table and an aggregate function in a subquery in the
SELECT list could cause a server exit. (Bug #21277074)
• GRANT created the account for nonexistent accounts even if the NO_AUTO_CREATE_USER SQL
mode was enabled. (Bug #21271571)
• A query with a NOT IN subquery that had COUNT(DISTINCT) could return incorrect results. (Bug
#21243772)
• When started using a very old data directory (from MySQL 5.0), the server could exit due to failure to
properly read the old grant tables. (Bug #21216433)
• A mulitple-table update involving generated columns that updated used a temporary table could
cause a server exit or raise an assertion. (Bug #21216067)
• For queries containing an expression of the form (x IN (subquery)) IN (subquery2), a
combination of semi-join and subquery materialization strategies could cause a server exit. (Bug
#21205577)
• If a query contained an outer join such as LEFT JOIN (t1,t2,...) and a hint was used to
disable join buffering on a right-side table but not on the others, a server exit occurred. (Bug
#21205282)
• For a cursor type of CURSOR_TYPE_READ_ONLY, retrieving the result set for the first execution of a
prepared CALL staement could be missing the first result set row if the data was numeric; raise an
assertion for debug builds if the data was string; cause loss of the server connection when calling
mysql_stmt_fetch(). (Bug #21199582)
• Dangling blob pointers could remain when closing an InnoDB table, resulting in a subsequent read
of invalid memory and a server exit. (Bug #21153489)
• For some operations where sorting or grouping required a temporary table, the table could have zero
columns and raise an assertion. (Bug #21143151)
• Queries containing an expression of the form (x IS NULL) IN (subquery) could cause a server
exit. (Bug #21139402)
• During server SSL file autogeneration, ca.pem briefly had insecure file permissions. (Bug
#21138119)
• An assertion could be raised due to incorrect error handling if a SELECT ... FOR UPDATE
subquery resulted in deadlock and caused a rollback. (Bug #21096444)
91
MySQL 5.7 Release Notes
• Selecting the result of an INSERT() function call to which input was passed as a hexidecimal string
could expose more information than was passed to the function. (Bug #21056907)
• Subqueries having COUNT() with GROUP BY could yield incorrect results. (Bug #21055139, Bug
#78029, Bug #21615020)
• The updatable property of a view is set during view creation. If the underlying table was dropped
and re-created as a nonupdatable one, the updatable property of the original view was not revised
accordingly. This could cause a server exit for attempts to insert or replace into the view is made.
(This problem was specific to views with multiple tables/views and did not occur with update
statements.) (Bug #21039264)
• The locking functions provided by the version_tokens plugin were renamed:
vtoken_get_read_locks(), vtoken_get_write_locks(), and vtoken_release_locks()
are now named version_tokens_lock_shared(), version_tokens_lock_exclusive(),
and version_tokens_unlock(), respectively.
These functions also failed to have any effect because they were implicitly unlocked at the end of the
statement in which they were set. (Bug #21034322, Bug #21280801)
• Servers linked against yaSSL and compiled with GCC 4.8.2 could fail to respond correctly to
connection attempts until several seconds after startup. (Bug #21025377)
• When upgrading an old data directory (MySQL 5.0 or 5.1), mysql_upgrade could fail to properly
read the mysql.proc table. (Bug #20968596)
• For tables with subpartitions, the server could exit due to incorrect error handling during partition
pruning if the partition could be identified but not the subpartition. (Bug #20909518)
• mysql_upgrade could fail to look for checked tables in the wrong database during the repair phase.
(Bug #20868496)
• DELETE could check privileges for the wrong database when table aliases were used. (Bug
#20777016)
• mysqldump used incorrect syntax for generated column definitions. (Bug #20769542)
• Within a trigger, use of a cursor that accessed OLD or NEW values from a row could cause a server
exit. (Bug #20760261)
• Failure during execution of an XA PREPARE statement could result in an invalid XA transaction
state. Subsequent attempts to start another XA transaction led to an ER_XAER_OUTSIDE error. (Bug
#20538956)
• The audit log plugin could audit accounts named in the audit_log_exclude_accounts system
variable. (Bug #20408206)
• If a generated foreign key index was renamed by the same ALTER TABLE statement that added a
new foreign key with the same name, the server could exit. (Bug #20146455)
• ALTER TABLE operations that dropped and added the same FULLTEXT index were not performed
as in-place (fast) operations that avoid using a temporary copy of the table. (Bug #20106837)
• When the number of days calculated by DATE_FORMAT() function was negative, the server could
exit. (Bug #19985318)
• ALTER TABLE operations to add or modify columns could create geometry columns containing
invalid data due to missing validation. (Bug #19880316)
• If range optimization was attempted on an index with a string column as its first part and values used
for comparison were fully truncated, comparisons would be incorrect and produce incorrect results.
(Bug #19333852)
References: This issue is a regression of: Bug #16407965.
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MySQL 5.7 Release Notes
• The server could hang due to incorrect cleanup of aggregate functions used in a query. (Bug
#18979515)
• The server could exit while checking for appropriate indexes to use for certain queries that used
aggregate function in the WHERE clause. (Bug #18706592)
• On Windows, the validate_password plugin could cause a server exit during the dictionary
check. (Bug #18636874)
• Invoking a stored program without qualifying it with the database name could lead to stored program
compilation errors. (Bug #18599181)
• EXPLAIN of statements containing GROUP_CONCAT() could cause a server exit. (Bug #17865675)
• The value of the FOUND_ROWS() function that returns the number of rows found in the previous
query could change during execution of the next query. Now the value of FOUND_ROWS() for the
previous query remains constant during execution of the next query. (Bug #17846246)
• Failure to check for error conditions could cause some updates or deletes to result in a server exit.
(Bug #17763238)
• On Windows, heap corruption in the audit log plugin caused server startup failure. (Bug #14700102)
• If the UPDATE part of INSERT ... ON DUPLICATE KEY UPDATE swapped two column values, the
server could read incorrect data and exit. (Bug #13901905)
• For debug builds, merging a derived table into an outer query block could raise an assertion. (Bug
#79502, Bug #22305361, Bug #21139722)
• mysqlpump failed to compile with Clang. (Bug #78637, Bug #21924096)
• For debug builds, a DROP TRIGGER statement could raise an assertion if the trigger was defined on
a table that contained a generated column. (Bug #78408, Bug #21824519)
• Some stress test files in the mysql-test/suite/innodb_stress directory had the executable
file mode set although they were not script files. (Bug #78403, Bug #21822413)
• Subqueries that used a derived table and contained a set function referring to a column from that
derived table might be aggregated in the wrong query block. (Bug #78250, Bug #21753180)
• For some inputs, ST_Union() could return an invalid geometry collection. (Bug #78206, Bug
#21689998)
• On non-Windows systems, setting range_alloc_block_size or query_alloc_block_size to
a value larger than 32 bits at startup could cause a server exit. The maximum value for these system
32
variables (on all platforms) is now limited to 2 − 1, rounded down to the nearest multiple of 1024.
(Bug #78188, Bug #21682231)
• mysql-test-run.pl now has an --valgrind-clients option that causes all clients started by
.test files to be run with valgrind. This option requires valgrind 3.9 or later.
In addition, several client memory leak issues were fixed. (Bug #78165, Bug #21672747)
• The mysql client parser incorrectly interpreted optimizer hint comments that contained ;, ", ', or `
characters. (Bug #78114, Bug #21646026)
• These Version Tokens issues were resolved:
• version_tokens_delete() now strips whitespace surrounding token names in its argument,
similar to version_tokens_set() and version_tokens_edit().
• Passing NULL to version_tokens_delete() caused a server exit.
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MySQL 5.7 Release Notes
• Passing an argument with an empty token name to to version_tokens_set() or
version_tokens_edit() caused a server exit.
• Passing NULL as the timeout value to version_tokens_lock_exclusive() or
version_tokens_lock_shared() caused a server exit.
(Bug #78111, Bug #21645001, Bug #21646106, Bug #21645944, Bug #21646017)
• Columns selected from the right-hand table of a left join, which was also a derived table, might
produce incorrect NULL value information when used in an IN subquery. (Bug #77980, Bug
#21574933)
References: This issue is a regression of: Bug #14358878.
• On Windows, if the MySQL server was started as a service, logging to the error log file was disabled.
(Bug #77977, Bug #21574096)
References: This issue is a regression of: Bug #21328041.
• In the setup_instruments Performance Schema table, it was possible to set memory
instrument to TIMED='YES', although memory operations are never timed. Now such attempts
are ignored. It was possible to set built-in memory instruments (with names of the form memory/
performance_schema/%) to ENABLED='YES', although built-in memory instruments cannot be
disabled. Now such attempts are ignored. (Bug #77944, Bug #21562212)
• mysqldump and mysqlpump output included sys schema stored programs even when the sys
schema was not dumped. (Bug #77926, Bug #21549860)
• RPM installation scripts failed if configuration files contained multiple datadir lines. Now the last
datadir line is used. (Bug #77878, Bug #21527467)
• An unnecessary memset() call invoked during Performance Schema digest operations has been
removed, which improves performance by reducing overhead. (Bug #77863, Bug #21528683)
• A potential race condition for the safe mutex implementation was corrected. This implementation is
enabled by default only for debug builds. (Bug #77862, Bug #21522888)
• Binary logging of CREATE USER and statements could log the hash of the password hash (rather
than the hash itself) when log_backward_compatible_user_definitions was enabled.
Binary logging of ALTER USER statements could include attributes not present in the original
statements.
In consequence of the fix for these issues, log_backward_compatible_user_definitions
has been replaced by log_builtin_as_identified_by_password. If this variable is enabled,
binary logging for CREATE USER statements involving built-in authentication plugins rewrites the
statements to include an IDENTIFIED BY PASSWORD clause, and SET PASSWORD statements are
logged as SET PASSWORD statements, rather than being rewritten to ALTER USER statements. (Bug
#77860, Bug #21516392, Bug #20535561)
• mysqld --initialize produced warnings about missing SSL files, which is unnecessary
because initialization does not require SSL. (Bug #77825, Bug #21498544)
• Valgrind errors could occur during partition pruning for tables containing generated columns. (Bug
#77782, Bug #21469535)
• When mysqlpump was invoked with the --defer-table-indexes option, it could generate
incorrect CREATE TABLE statements for tables with a foreign key and a primary key but not a
secondary index. (Bug #77759, Bug #21462732)
• An attempt to use a previously unused time zone with CONVERT_TZ() could produce warnings
or errors or (in debug builds) raise an assertion if GTIDs were enabled but the binary log was not
enabled.
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MySQL 5.7 Release Notes
In debug builds, an attempt to use a previously unused time zone with CONVERT_TZ() or as the
value of the time_zone system variable inside a stored program could raise an assertion. (Bug
#77753, Bug #21459999, Bug #77748, Bug #21459795)
• The server initialization script used for the service mysql status command on Linux sometimes
incorrectly reported that the server was stopped. (Bug #77696, Bug #21768876)
• ALTER TABLE could raise an assertion for a table with an indexed virtual column having a column
position greater than 64. (Bug #77656, Bug #21391781)
• Evaluation of virtual generated columns could fail to evaluate all base columns and result in invalid
memory reads. (Bug #77653, Bug #21390605)
• For statements of the form CREATE TABLE ... SELECT, where the table was defined to contain
a DECIMAL UNSIGNED, calculation of the row size was incorrect, leading to incorrect values in the
table. (Bug #77636, Bug #21383896)
• A WHERE predicate containing both TRIM(LEADING ..) and TRIM(TRAILING ...) could be
incorrectly optimized away. (Bug #77631, Bug #21447969)
• For wait events, the Performance Schema uses the CYCLE timer by default, but failed to fall back to
a different timer if CYCLE was unavailable. (Bug #77577, Bug #21374104)
• A disk-full condition during execution of a CREATE TABLESPACE statement caused a server exit.
(Bug #77556, Bug #21347001)
• A privilege precheck for derived tables could fail and cause a server exit. (Bug #77525, Bug
#21338077)
• For spatial functions, input polygons were automatically closed if open. However, the Open
Geospatial Consortium guidelines require that input polygons already be closed. Unclosed polygons
are now rejected as invalid rather than being closed. (Bug #77505, Bug #21327888)
• When a VIRTUAL generated column was added to a table, it was not ensured that data being
calculated by the generated column expression would not be out of range for the column. This could
lead to inconsistent data being returned and unexpectedly failed statements.
ALTER TABLE now supports WITHOUT VALIDATION and WITH VALIDATION clauses to control
whether ALTER TABLE validates the data for a VIRTUAL generated column:
• With WITHOUT VALIDATION (the default if neither clause is specified), an in-place operation is
performed (if possible), data integrity is not checked, and the statement finishes more quickly.
However, later reads from the table might report warnings or errors for the column if values are out
of range.
• With WITH VALIDATION, ALTER TABLE copies the table. If an out-of-range or any other error
occurs, the statement fails. Because a table copy is performed, the statement takes longer.
WITHOUT VALIDATION and WITH VALIDATION are permitted only with ADD COLUMN, CHANGE
COLUMN, and MODIFY COLUMN operations. (Bug #77478, Bug #21317507)
• For some string functions, data was truncated when evaluated in subqueries due to incorrect
space calculations when creating temporary tables to hold intermediate results. (Bug #77473, Bug
#21317406)
• Statement digests did not include information about optimizer hint comments, causing statements
with and without hints to be aggregated. (Bug #77414, Bug #21286261)
• A predicate of the form WHERE ROUND(X,Y) > 0, where X is a column name and Y is a program
local variable, could return false when it should return true. (Bug #77391, Bug #21279005)
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MySQL 5.7 Release Notes
• ST_SymDifference() with multipolygon arguments could return incorrect results. (Bug #77372,
Bug #21263152)
• Updating VARCHAR and TEXT columns in the same UPDATE statement could produce incorrect
results. When a VARCHAR column was assigned to a TEXT column and the VARCHAR column was
then set to a different value, the TEXT column's result contained the VARCHAR column's new value.
(Bug #77135, Bug #21143080)
• A subquery in a HAVING clause that returned more than 1 row could cause a server exit.
Additional to the bug fix, EXPLAIN now displays Zero limit rather than Impossible WHERE
when optimizing a query with LIMIT 0. (Bug #76998, Bug #21067109)
• If an INFORMATION_SCHEMA query that performed a table-open operation encountered a corrupt
table and attempted to repair it, a deadlock could occur, resulting in an aborted transaction without
an appropriate error being reported. Such queries now do not attempt table repair. (Bug #76912, Bug
#21021848)
• mysqladmin -u root -p could exit with a segmentation fault. (Bug #76538, Bug #20802751)
• The optimizer sometimes generates an index for a derived table (subquery in the FROM clause). If
this occurred for a statement executed within a stored program, a memory leak could occur. (Bug
#76349, Bug #20728894)
• Optimizer estimates for filtering conditions could lead to suboptimal execution plans if the expected
number of rows selected from a table was between 0 and 1. The estimate is now made to be at least
1. (Bug #76314, Bug #20701585)
• If a file was specified using an --init-file option, mysqld --initialize produced errors for
statements in the file such as GRANT that affect user accounts. (Bug #75918, Bug #20546898)
• The optimizer could incorrectly assume an out-of-memory condition while optimizing a range scan
for the OR operator, resulting in overestimation of the number of qualifying rows. (Bug #75248, Bug
#20229614)
• The events_statements_history Performance Schema table could have an ERRORS column
value of 0 when other columns indicated there were errors. (Bug #74614, Bug #19929832)
• View creation from a UNION failed with a duplicate-column error if a SELECT statement in the UNION
other than the first used the same column name multiple times. (Bug #74539, Bug #19886430)
• Timestamp values written to the slow query log could be incorrect. (Bug #73974, Bug #19646918)
• When the mysql client was used to connect to the server in batch mode using an account with
an expired password, the error message was not meaningful. mysql now reports “Please use -connect-expired-password option or invoke mysql in interactive mode” in this case. (Bug #72696,
Bug #21464621)
• For UPDATE statements with ORDER BY, the optimizer could perform an unnecessary filesort on
a key that was used for scanning as well as being updated. (Bug #72518, Bug #18698556)
• For a query with many range conditions, the optimizer would estimate that too much memory would
be required for a range scan and fall back to a less optimal plan, such as a full table scan.
A new range_optimizer_max_mem_size system variable now controls the limit on memory
consumption for the range optimizer. A value of 0 means “no limit.” If an execution plan considered
by the optimizer uses the range access method but the optimizer estimates that the amount of
memory needed for this method would exceed the limit, it abandons the plan and considers other
plans. (Bug #70247, Bug #17413040, Bug #17769777)
• Empty XML elements having the form <element/> were not handled correctly by the LOAD XML
statement. (Bug #67542, Bug #16171518)
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MySQL 5.7 Release Notes
• As the number of open MyISAM tables increased, lookups to check whether a table was open
became expensive, particularly when the table was not open. Lookup performance has been
improved, with the overhead reduction especially beneficial for selects on large number of tables
with large values of table_open_cache and table_definition_cache. (Bug #49177, Bug
#11757169)
Changes in MySQL 5.7.8 (2015-08-03, Release Candidate)
This release adds support for Debian 8 and Ubuntu 15.04.
• Account Management Notes
• Backup Notes
• Compilation Notes
• Configuration Notes
• JSON Notes
• Optimizer Notes
• Packaging Notes
• Performance Schema Notes
• Plugin Service Notes
• Plugin Notes
• Security Notes
• Spatial Data Support
• SQL Mode Notes
• Functionality Added or Changed
• Bugs Fixed
Account Management Notes
• The CREATE USER statement now supports an IF NOT EXISTS clause that causes the statement
to produce a warning for each named account that already exists, rather than an error. The ALTER
USER and DROP USER statements now support an IF EXISTS clause that cause the statements to
produce a warning for each named account that does not exist, rather than an error. For details, see
CREATE USER Syntax, ALTER USER Syntax, and DROP USER Syntax.
These statement variants can be useful in replication scenarios when the set of accounts differs
between master and slave. They also permit scripting account-management operations that
otherwise would terminate for statement errors.
• The maximum length of MySQL user names has been increased from 16 to 32 characters, which
provides greater flexibility in choosing the user name part of MySQL account names. The change
affects permitted user names in these contexts:
• Account-management statements, such as CREATE USER, GRANT, REVOKE, and SHOW GRANTS.
• Statements that support a DEFINER clause, such as CREATE PROCEDURE and CREATE VIEW.
• Other statements with clauses that contain user names, such as CHANGE MASTER TO and
CREATE SERVER.
• Columns that store user names in mysql system database, INFORMATION_SCHEMA, and
Performance Schema tables have been widened to accommodate 32 characters.
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MySQL 5.7 Release Notes
There are no changes in the client/server protocol, which exchanges user names as null-terminated
strings. However, third-party programs that use this protocol to communicate may need to be
modified if they use or store user names based on the assumption of 16 characters maximum.
The increase in maximum user name length has implications for MySQL administration:
• Replication implication: Replication of user names longer than 16 characters to a slave that
supports only shorter user names will fail. However, this should occur only when replicating from a
newer master to an older slave, which is not a recommended configuration.
• Downgrade implication: If a newer server supports any accounts with a user name longer than
16 characters, downgrades to an older version of MySQL that supports only shorter names is not
possible.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate this change in user name length.
Backup Notes
• A new client program, mysqlpump, provides an alternative to mysqldump. Its features include:
• Parallel processing of databases, and of objects within databases, to speed up the dump process
• Better control over which databases and database objects (tables, stored programs, user
accounts) to dump
• Dumping of user accounts as account-management statements (CREATE USER, GRANT) rather
than as inserts into the mysql system database
• Capability of creating compressed output
• Progress indicator (the values are estimates)
• For dump file reloading, faster secondary index creation for InnoDB tables by adding indexes after
rows are inserted
For more information, see mysqlpump — A Database Backup Program.
There are some notable differences between mysqlpump and mysqldump:
• With no options, mysqlpump dumps everything, whereas mysqldump dumps nothing.
• For mysqlpump, the --routines and --events are enabled by default, whereas for
mysqldump, they are disabled by default.
Compilation Notes
• The required version of the Boost library for server builds has been raised from 1.57.0 to 1.58.0.
(Bug #76354, Bug #20721087)
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Configuration Notes
• The default configuration for systemd now sets LimitNOFILE to 5000 to increase the number
of file descriptors available to the MySQL server. This change applies to Linux systems on which
MySQL installation is performed using RPM packages. On such systems, the number of descriptors
available is often set by the operating system to 1024. The change causes the number of descriptors
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MySQL 5.7 Release Notes
to match the --open-files-limit option default value of 5000. To configure a different number
of descriptors, set LimitNOFILE as described at Managing MySQL Server with systemd. (Bug
#21073014)
• The libmysqld embedded server took its default secure_file_priv value from the
INSTALL_SECURE_FILE_PRIVDIR CMake option, but cannot share the same directory with a
non-embedded server. The new INSTALL_SECURE_FILE_PRIV_EMBEDDEDDIR option enables a
separate directory to be specified for libmysqld. The default value is NULL. (Bug #20770671)
JSON Notes
• JSON: MySQL now supports a native JSON data type that enables efficient access to data in JSON
(JavaScript Object Notation) documents. The JSON data type provides these advantages over
storing JSON-format strings in a string column:
• Automatic validation of JSON documents stored in JSON columns. Invalid documents produce an
error.
• Optimized storage format. JSON documents stored in JSON columns are converted to an internal
format that permits efficient access to document elements.
Along with the JSON data type, a set of SQL functions is available to enable operations on JSON
values, such as creation, manipulation, and searching. In addition, the CONVERT() and CAST()
functions can convert values between JSON and other types.
For more information, see The JSON Data Type, and JSON Functions.
Optimizer Notes
• The optimizer now is able to use indexes on generated columns, even when queries do not refer to
such columns directly by name. The optimizer recognizes query expressions that match definitions of
generated columns and uses indexes from those columns as appropriate during query execution. For
details, see Optimizer Use of Generated Column Indexes.
• The optimizer cost model has a new memory_block_read_cost parameter in the
mysql.engine_cost table representing the cost of reading an index or data block from an inmemory database buffer.
Together with the existing io_block_read_cost parameter representing the cost of reading a
block from disk, this change enables cost models for data access methods to take into account
the costs of reading information from different sources; that is, the cost of reading information from
disk versus reading information already in a memory buffer. For the initial implementation, the
default value of memory_block_read_cost is the same as io_block_read_cost. Tuning the
values remains as future work, although you can change the values to see how that affects query
performance. For more information, see The Optimizer Cost Model.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate this change into the mysql system database.
• The optimizer hint capability introduced in MySQL 5.7.7 has been expanded to subquery execution
strategies. Subquery hints affect whether to use semi-join transformations and which semi-join
strategies to permit, and, when semi-joins are not used, whether to use subquery materialization or
IN-to-EXISTS transformations. Examples:
SELECT /*+ SEMIJOIN(FIRSTMATCH, LOOSESCAN) */ * FROM t1 ...;
SELECT id, a IN (SELECT /*+ SUBQUERY(MATERIALIZATION) */ a FROM t1) FROM t2;
SELECT * FROM t2 WHERE t2.a IN (SELECT /*+ SUBQUERY(INTOEXISTS) */ a FROM t1);
For more information, see Subquery Optimizer Hints.
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MySQL 5.7 Release Notes
There is also a new duplicateweedout flag for the optimizer_switch system variable. This
flag enables use of optimizer_switch to specify whether to use the Duplicate Weedout semi-join
strategy, which was not previously possible.
Packaging Notes
• Microsoft Windows: For Windows, the MSI installer package no longer includes debugging
binaries/information components (including PDB files). These are available in a separate Zip archive
named mysql-VERSION-winx64-debug-test.zip for 64-bit and mysql-VERSION-win32debug-test.zip for 32-bit. (Bug #18296012)
Performance Schema Notes
• Current-event timing now provides more information. Previously, while a wait, stage, statement,
or transaction event was executing, the respective tables displayed the event with TIMER_START
populated, but with TIMER_END and TIMER_WAIT as NULL:
events_waits_current
events_stages_current
events_statements_current
events_transactions_current
To make it possible to determine how how long a not-yet-completed event has been running, the
timer columns now are set as follows:
• TIMER_START is populated (unchanged from previous behavior)
• TIMER_END is populated with the current timer value
• TIMER_WAIT is populated with the time elapsed so far (TIMER_END − TIMER_START)
To find events that have not yet completed (that is, have no END_EVENT_ID) and have taken longer
than N picoseconds thus far, monitoring applications can use this expression in queries:
WHERE END_EVENT_ID IS NULL AND TIMER_WAIT > N
(Bug #75156, Bug #20889406)
• The Performance Schema incorporates these changes:
• The show_compatibility_56 system variable default value, previously ON, has been changed
to OFF. Applications that require 5.6 behavior should set this variable to ON until such time as they
have been migrated to the new behavior for system variables and status variables. See Migrating
to Performance Schema System and Status Variable Tables
• When the Performance Schema session variable tables produced output, they included no
rows for global-only variables and thus did not fully reflect all variable values in effect for the
current session. This has been corrected so that each table has a row for each session variable,
and a row for each global variable that has no session counterpart. This change applies to the
session_variables and session_status tables.
• It is no longer required that the show_compatibility_56 system variable be OFF for the
Performance Schema system variable tables to produce output. The tables now produce
output regardless of the variable value. This change applies to the global_variables,
session_variables, and variables_by_thread tables.
• WHERE clauses for SHOW VARIABLES and SHOW STATUS were deprecated in MySQL 5.7.6. This
restriction has been lifted so that WHERE is supported as before 5.7.6.
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MySQL 5.7 Release Notes
• The metadata_locks table now displays tablespace locks. Rows for these locks have an
OBJECT_TYPE value of TABLESPACE.
• The Performance Schema logs wait, stage, statement, and transaction events in these history
tables:
events_waits_history
events_waits_history_long
events_stages_history
events_stages_history_long
events_statements_history
events_statements_history_long
events_transactions_history
events_transactions_history_long
Previously, historical event logging was controlled entirely by enabling or disabling history-related
consumers in the setup_consumers table. These flags are global to the server, with the result
that historical data was collected either for all threads or no threads.
The Performance Schema now uses history consumers in conjunction with the setup_actors
table to make it possible to control collection of historical events per host, user, or account
(combination of host and user). This table has a new HISTORY column that indicates whether
to collect historical events (subject also to which history consumers are enabled), and each new
foreground thread is matched against rows in the table. If a matching row is found, its HISTORY
value is recorded in the row for the thread in the threads table, which also now has a HISTORY
column.
Enabling historical event logging for a given session can be done independent of enabling
instrumentation for it. Consequently, you can control more precisely what events are logged in
history tables, with these advantages:
• A decrease in runtime overhead when historical data is needed only for a subset of the
instrumented sessions.
• A reduction of noise in the history tables, facilitating troubleshooting on busy servers that
generate a large number of events.
For more information, see Pre-Filtering by Thread, The setup_actors Table, and The threads
Table.
• The threads table now contains a CONNECTION_TYPE column that indicates the connection
protocol. It can be used to determine how the connection was made. Permitted values are TCP/
IP (TCP/IP connection established without SSL), SSL/TLS (TCP/IP connection established with
SSL), Socket (Unix socket file connection), Named Pipe (Windows named pipe connection), and
Shared Memory (Windows shared memory connection).
Connection-type information is also written to the general query log for new connections, and the
audit log interface was revised to incorporate the connection type.
For more information, see The threads Table, The General Query Log, and Writing Audit Plugins.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
References: See also: Bug #76167, Bug #20652173, Bug #20684424, Bug #20811494.
Plugin Service Notes
• MySQL server plugins have access to server “services,” as described in MySQL Services for
Plugins. MySQL distributions now include plugins that demonstrate how to test plugin service
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MySQL 5.7 Release Notes
APIs. The test_framework plugin is a bare bones plugin that shows the minimum required
framework for service testing. The test_services and test_services_threaded plugins
demonstrate how to test the my_snprintf and my_plugin_log_service services in unthreaded
and threaded contexts. For more information, see http://dev.mysql.com/doc/dev/mysql-server/
PAGE_PLUGINS.html, in http://dev.mysql.com/doc/dev/mysql-server/.
• MySQL distributions now provide a locking interface that implements locks with three attributes: Lock
namespace, lock name, and lock mode. The namespace enables different applications to use the
same lock names without colliding by creating locks in separate namespaces. Locks can be created
with a mode of either read (shared) or write (exclusive).
This locking interface is available at two levels: 1) As a C language interface, callable as a plugin
service from server plugins or user-defined functions; 2) At the SQL level, as a set of user-defined
functions that map onto calls to the service routines. For more information, see The Locking Service.
The interface provided by the locking service is distinct from that provided by GET_LOCK() and
related SQL functions (see Miscellaneous Functions). For example, GET_LOCK() does not
implement namespaces and provides only exclusive locks, not distinct read and write locks.
Plugin Notes
• The initial implementation for query rewrite plugins used its own API. This API has been
reimplemented to use the audit plugin API. For more information, see Writing Audit Plugins. One
effect of the query rewrite plugin reimplementation is reduced overhead.
• MySQL distributions now include Version Tokens, a feature that enables creation of and
synchronization around server tokens that applications can use to prevent accessing incorrect or
out-of-date data. Version Tokens is based on a plugin library that implements a version_tokens
plugin and a set of user-defined functions. For more information, see Version Tokens.
• These changes were made for the Rewriter query rewrite plugin (see The Rewriter Query Rewrite
Plugin):
• There is now a single installation script, install_rewriter.sql.
Previously, there were two installation scripts, install_rewriter.sql and
install_rewriter_with_optional_columns.sql, which differed in whether they
created the pattern_digest and normalized_columns columns of the rewrite_rules
table. install_rewriter.sql now always creates those columns, so there is no need for
install_rewriter_with_optional_columns.sql.
• The enabled column of the rewrite_rules table is now defined as ENUM('YES,'NO') rather
than as CHAR(1). Correspondingly, to enable a rule, set this column to YES rather than Y.
To upgrade if you have previously installed the Rewriter plugin, uninstall it by running the
uninstallation script first, then run the installation script. After reinstalling, load your rewrite rules
again (this is necessary because uninstalling drops the rules table). For instructions, see Installing or
uninstalling the Rewriter Query Rewrite Plugin.
Security Notes
• MySQL Community Edition RPM packages now invoke mysql_ssl_rsa_setup during installation
to create default SSL and RSA key and certificate files. (Bug #20855737)
• my_print_defaults now masks passwords. To display passwords in cleartext, use the new -show option. In addition, The output for client programs invoked with the --print-defaults
option now masks passwords. (Bug #19953365, Bug #20903330)
• A new system variable, require_secure_transport, enables administrators to require all client
connections to the server to be made using some form of secure transport. Qualifying connections
are TCP/IP connections that use SSL, or connections that use a socket file (on Unix) or shared
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MySQL 5.7 Release Notes
memory (on Windows). When this variable is enabled, the server rejects nonsecure connection
attempts, which fail with an ER_SECURE_TRANSPORT_REQUIRED error.
This capability supplements per-account SSL requirements, which take precedence. For example, if
an account is defined with REQUIRE SSL, enabling require_secure_transport does not make
it possible to use the account to connect using a Unix socket file.
Spatial Data Support
• ST_NumInteriorRing() was added as more a standard-compliant alias of
ST_NumInteriorRings(). (Bug #77598, Bug #21362781)
• All spatial computations now are done using Boost.Geometry functions. All older non-Boost-based
algorithms have been removed. (Bug #77444, Bug #21300713)
• Geometry constructor functions that take WKT or WKB values (such as ST_GeomFromText()
and ST_GeomFromWKB()) did not check for trailing garbage bytes. They now reject trailing
nonwhitespace characters and produce an error. (Bug #77244, Bug #21198064)
• Geometry object constructor functions such as Point() and MultiPolygon() now are stricter
about rejecting invalid arguments. (Bug #76337, Bug #20712775)
SQL Mode Notes
• In MySQL 5.7.4, the ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE
SQL modes were changed so that they did nothing when named explicitly. Instead, their effects were
included in the effects of strict SQL mode (STRICT_ALL_TABLES or STRICT_TRANS_TABLES). The
intent was to reduce the number of SQL modes with an effect dependent on strict mode and make
them part of strict mode itself.
However, the change to make strict mode more strict by including
ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE caused some
problems. For example, in MySQL 5.6 with strict mode but not NO_ZERO_DATE enabled, TIMESTAMP
columns can be defined with DEFAULT '0000-00-00 00:00:00'. In MySQL 5.7.4 with the same
mode settings, strict mode includes the effect of NO_ZERO_DATE and TIMESTAMP columns cannot
be defined with DEFAULT '0000-00-00 00:00:00'. This causes replication of CREATE TABLE
statements from 5.6 to 5.7.4 to fail if they contain such TIMESTAMP columns.
The long term plan is still to have the three affected modes be included in strict SQL mode and to
remove them as explicit modes in a future MySQL release. But to restore compatibility in MySQL 5.7
with MySQL 5.6 strict mode and to provide additional time for affected applications to be modified,
the following changes have been made:
• ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE again have an
effect when named explicitly. This reverts a change made in MySQL 5.7.4.
• ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE are no longer part
of strict SQL mode. This reverts a change made in MySQL 5.7.4.
• ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE are
now included in the default sql_mode value, which as a result includes these modes:
ONLY_FULL_GROUP_BY, STRICT_TRANS_TABLES, NO_ZERO_IN_DATE, NO_ZERO_DATE,
ERROR_FOR_DIVISION_BY_ZERO, NO_AUTO_CREATE_USER, and NO_ENGINE_SUBSTITUTION.
With the preceding changes, stricter data checking is still enabled by default, but the individual
modes can be disabled in environments where it is currently desirable or necessary to do so.
Although ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE again can
be used separately from strict mode, it is intended that they be used together. As a reminder, a
warning now occurs if they are enabled without also enabling strict mode or vice versa.
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MySQL 5.7 Release Notes
References: See also: Bug #75439, Bug #20367829.
Functionality Added or Changed
• InnoDB: The adaptive hash index search system is now partitioned, with each index bound to a
specific partition, and each partition protected by a separate latch. Partitioning is controlled by the
innodb_adaptive_hash_index_parts configuration option.
Prior to MySQL 5.7.8, the adaptive hash index search system was protected by a single latch
(btr_search_latch) which could become a point of contention. To reduce contention,
innodb_adaptive_hash_index_parts is set to 8 by default. The maximum setting is 512. (Bug
#20985298)
• InnoDB: The new innodb_log_checksum_algorithm option specifies how to generate and
verify the checksum stored in redo log disk blocks. innodb_log_checksum_algorithm supports
same algorithms as innodb_checksum_algorithm, which include innodb, crc32, none, and
their associated strict forms. Previously, only the innodb algorithm was supported for redo log disk
blocks. innodb_log_checksum_algorithm=innodb is the default setting. Thanks to Alexey
Kopytov for the patch. (Bug #20531208, Bug #75595)
• InnoDB: InnoDB now supports secondary indexes on virtual generated columns. For more
information, see Secondary Indexes and Generated Columns.
• InnoDB: Internal server-layer functions were added to allow InnoDB purge threads to construct
and destroy thread handle objects, and to compute virtual generated column index values when a
table object is not present. This enhancement was required to support secondary indexes on virtual
generated columns.
• InnoDB: Virtual generated column values no longer occupy space in database rows. With this
change, a table rebuild is no longer required when adding or dropping virtual generated columns.
Only a system table update is necessary, to register the new metadata.
Virtual generated columns are still represented in InnoDB metadata. The N_COLS field of
INNODB_SYS_TABLES still counts virtual generated columns, and INNODB_SYS_COLUMNS still
includes virtual generated column metadata.
A new INFORMATION_SCHEMA table, INNODB_SYS_VIRTUAL, provides metadata about columns
upon which virtual generated columns are based.
• InnoDB: InnoDB now supports page-level compression for file-per-table tablespaces. Page
compression is enabled by specifying the COMPRESSION attribute when creating or altering a table.
Supported compression algorithms include Zlib and LZ4. This feature, which is referred to as
transparent page compression, relies on sparse file and hole punching support. It is supported on
Windows with NTFS, and a subset of MySQL-supported Linux platforms where the kernel level
provides hole punching support.
For more information about this feature, see InnoDB Page Compression.
• InnoDB: The new innodb_flush_sync configuration option, which is enabled by default, causes
the innodb_io_capacity setting to be ignored for bursts of I/O activity that occur at checkpoints.
To adhere to the limit on InnoDB background I/O activity defined by the innodb_io_capacity
setting, disable innodb_flush_sync.
• InnoDB: The default value for innodb_purge_threads and innodb_page_cleaners
was changed from 1 to 4. If the number of page cleaner threads exceeds the number of
buffer pool instances, innodb_page_cleaners is automatically set to the same value as
innodb_buffer_pool_instances.
• Replication: The behavior of SET GTID_PURGED has been changed so that it does not add any
GTIDs to Previous_gtids_log_event and does not rotate the binary log. Instead the GTIDs
104
MySQL 5.7 Release Notes
are added to the mysql.gtid_executed table. This fix ensures that it is safe in all cases to use
binlog_gtid_simple_recovery=1 for a server using MySQL 5.7.8 or later, where all binary logs
were generated by servers using MySQL 5.7.8 or later. (Bug #75767, Bug #20470724)
• Replication: When using a multi-threaded slave, each worker thread has its own queue of
transactions to process. In previous MySQL versions, STOP SLAVE waited for all workers to
process their entire queue. This logic has been changed so that STOP SLAVE first finds the newest
transaction that was committed by any worker thread. Then, it waits for all workers to complete
transactions older than that. Newer transactions are not processed. The new logic allows STOP
SLAVE to complete faster in case some worker queues contain multiple transactions. (Bug #75525,
Bug #20369401)
• Solaris: Solaris tarball and PKG distributions no longer have -gcc in the distribution file names.
(Bug #21047137)
• Previously, the max_digest_length system variable controlled the maximum digest length for all
server functions that computed statement digests. However, whereas the Performance Schema may
need to maintain many digest values, other server functions such as query rewrite plugins need only
one digest per session. Increasing the max_digest_length value has little impact on total memory
requirements for those functions, but can increase Performance Schema memory requirements
significantly. To enable configuring digest length separately for the Performance Schema, its digest
length is now controlled by the new performance_schema_max_digest_length system
variable. (Bug #20963147)
• The server now prints more descriptive diagnostic messages for bad values of secure_file_priv.
(Bug #20771331)
• For attempts to create a multiple-column SPATIAL index, the server previously returned an “Incorrect
arguments to SPATIAL INDEX” error. Now it returns ER_TOO_MANY_KEY_PARTS (“Too many key
parts specified; max 1 parts allowed”). (Bug #18320371)
• For tables that contain object information, the Performance Schema now uses lowercase stored
program names. (Bug #17818062)
• To make the effect of password-change operations more clear, mysql_secure_installation
now displays the user whose password is being changed. (Bug #17343687)
• The patch number of the C client library is now increased for each patch version of the server. This
number has the format major.minor.patch. (Bug #77544, Bug #21341481)
• The max_statement_time system variable was renamed to max_execution_time.
The Max_statement_time_exceeded, Max_statement_time_set,
and Max_statement_time_set_failed status variables were renamed
to Max_execution_time_exceeded, Max_execution_time_set, and
Max_execution_time_set_failed.
The MAX_STATEMENT_TIME option for SELECT statements was removed because its functionality
is now available using the more general optimizer hint syntax (see Optimizer Hints). Statements that
begin like this:
SELECT MAX_STATEMENT_TIME = N ...
Should be rewritten to begin like this:
SELECT /*+ MAX_EXECUTION_TIME(N) */ ...
There are some minor implementation differences between the two. MAX_STATEMENT_TIME was
not permitted in non-top-level SELECT statements such as subqueries, or in stored programs, and
produced an error. MAX_EXECUTION_TIME is permitted in those contexts, but is ignored. (Bug
#77461, Bug #21306646, Bug #77460, Bug #21306392, Bug #77459, Bug #21306319)
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MySQL 5.7 Release Notes
• GeometryCollection() with no arguments is now permitted as a way to create an empty
geometry. (Bug #77114, Bug #21127270)
• The shutdown timeout value in /etc/init.d/mysqld was too short for some environments. The
value has been increased from 60 seconds to 600 seconds. (Bug #76900, Bug #20987568)
• Use of the optimizer cost model was extended to estimating index scan costs within
test_if_cheaper_ordering() for the I/O cost of accessing table blocks. (Bug #76804, Bug
#20947871)
• For MySQL install operations on OS X from DMG packages, if a a random root account password
is generated, it now is displayed in a dialog box. (Bug #76792, Bug #20930305)
• mysqldump no longer dumps the sys schema by default. It is still possible to dump it by naming it
explicitly on the command line (for example, mysqldump --databases sys). (Bug #76735, Bug
#20902791)
• For non-TCP/IP connections, these changes were made when --ssl was specified to force SSL to
be used:
• For named pipe and shared memory connections, attempts to use SSL now produce an error
because these connections use non-network protocols.
• For Unix socket file connections, SSL does not add any security. The connection is permitted,
but the mysql client now produces a warning that SSL does not add anything for this connection
protocol.
(Bug #76508, Bug #20785409, Bug #21025587)
• mysql_ssl_rsa_setup now has a --uid=name option that enables specifying the owner for any
files created by the program (if the program is executed as root). (Bug #76369, Bug #20726413)
• MySQL distributions now include an innodb_stress suite of test cases. Thanks to Mark Callaghan
for the contribution. (Bug #76347, Bug #20717127)
• The data type for generated columns now permits the COLLATE attribute. (Bug #76329, Bug
#20709487)
• Connections for the FEDERATED storage engine now set the program_name session connection
attribute to federated to permit identification of the connection source. (Bug #68781, Bug
#16555730)
• Previously, changes to the validate_password plugin dictionary file (named by the
validate_password_dictionary_file system variable) while the server was running required
a restart for the server to recognize the changes. Now validate_password_dictionary_file
can be set at runtime and assigning a value causes the named file to be read without a restart.
In addition, two new status variables are available.
validate_password_dictionary_file_last_parsed indicates when the dictionary file was
last read, and validate_password_dictionary_file_words_count indicates how many
words it contains. (Bug #66697, Bug #14588145)
• The error produced for a COM_FIELD_LIST command with too much data was changed from
ER_UNKNOWN_COM_ERROR to the more informative ER_MALFORMED_PACKET. (Bug #53699, Bug
#11761229)
• A new system variable, disabled_storage_engines, enables administrators to designate
storage engines that cannot be used to create new tables or tablespaces. By default, this variable
is empty (no engines disabled), but it can be set to a comma-separated list of one or more engines.
Any engine named in the value cannot be used to create tables or tablespaces with CREATE
TABLE or CREATE TABLESPACE, and cannot be used with ALTER TABLE ... ENGINE or
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MySQL 5.7 Release Notes
ALTER TABLESPACE ... ENGINE to change the storage engine of existing tables or tablespaces.
Attempts to do so result in an ER_DISABLED_STORAGE_ENGINE error.
disabled_storage_engines does not restrict other DDL statements for existing tables, such
as CREATE INDEX, TRUNCATE TABLE, ANALYZE TABLE, DROP TABLE, or DROP TABLESPACE.
This permits a smooth transition so that existing tables or tablespaces that use a disabled
engine can be migrated to a permitted engine by means such as ALTER TABLE ... ENGINE
permitted_engine.
• MySQL distributions no longer include the sql-bench directory. The INSTALL_SQLBENCHDIR
CMake option has also been removed.
References: See also: Bug #21303289.
• The default value of the table_open_cache_instances system variable has been increased
from 1 to 16.
• The read_only system variable enables the server to be put into read-only mode, in which
the server permits client updates only from users who have the SUPER privilege. A new
super_read_only system variable, if enabled, prohibits client updates even from users who have
SUPER. “Super” read-only mode can be useful for operations such as preparing a server for a move
or upgrade because it prevents all client users from modifying data, even administrators.
• The so-called “fast mutex” code has been removed from the server sources. It provides no
measurable benefit, complicates the code, and is problematic for certain architectures such as
POWER8. The (undocumented) WITH_FAST_MUTEXES CMake option has also been removed.
References: See also: Bug #37703, Bug #11748914, Bug #72806, Bug #18871517, Bug #72807,
Bug #18871138, Bug #72805, Bug #18870931.
• mysqld_safe no longer uses the data directory as a possible location for setting MYSQL_HOME.
(This has been deprecated since MySQL 5.0.)
Bugs Fixed
• Incompatible Change: The mysql_parser plugin service interface defined in the
service_parser.h header file was incorrect for the case that the MYSQL_DYNAMIC_PLUGIN
macro was defined. The test for this symbol used the wrong name, so the interface did not enable
the proper code. The test has been corrected, and some adjustments made to the API for function
pointer members within the mysql_parser_service_st structure:
• Some function pointer names began with mysql_parser_, others with mysql_. For consistency,
function pointer member names that began with mysql_parser_ were changed to begin with
mysql_.
• The missing mysql_get_statement_digest function pointer member was added.
These modifications change the service API. Any plugin to be used with this version of MySQL that
relies on the service must be recompiled. (Bug #20856729)
• Incompatible Change: Internal storage format for VIRTUAL generated columns was modified. For
MyISAM tables with such columns, this is an incompatible change; for upgrades, use ALTER TABLE
to drop the columns before the upgrade and add them again after the upgrade. (Bug #77312, Bug
#21237637)
• Incompatible Change: For multibyte character sets, LOAD DATA could fail to allocate space
correctly and ignore input rows as a result.
A consequence of this change is that previously accepted invalid character data is now rejected,
which can cause issues if you replicate from an older server without this bug fix to a newer server
with this bug fix. For example, if an older server that accepts invalid utf8 character set data
107
MySQL 5.7 Release Notes
replicates to a newer server with this bug fix, the newer server will not accept the data and replication
will fail with an “Invalid utf8 character string” error. Solutions for this issue include:
• Correct the invalid data so that it is correct for the character set
• Use a different character set for which the data is not invalid
• Upgrade the master to a version that has the bug fix so that master and slave interpret the data the
same way
(Bug #76237, Bug #20683959, Bug #23080148)
References: This issue is a regression of: Bug #14653594.
• InnoDB; Partitioning: In certain rare cases the optimizer pruned all partitions for an InnoDB
table but failed to remove the table from consideration as a source for obtaining matches, instead
calling for the table to be initialized and prepared for fetching records. This occurred when the active
index was not set during initialization. To fix this problem, we now set the active index ID during
initialization even if there are no partitions to select from. This behavior also matches the way the
same case is already handled in MySQL 5.6. (Bug #21211524)
• InnoDB; Partitioning: Sorted index reads on partitioned InnoDB tables added rows to the prefetch
cache, which could cause rows from the wrong partition since the prefetch cache does not support
partitioned tables. Now the the prefetch cache is disabled in such cases. (Bug #20584754)
• InnoDB; Partitioning: ALTER TABLE ADD UNIQUE INDEX failed when run concurrently with an
INSERT on the same partitioned InnoDB table. (Bug #20510811, Bug #75834)
• InnoDB; Partitioning: The CREATE_TIME column of the INFORMATION_SCHEMA.TABLES table
now shows the correct table creation time for partitioned InnoDB tables. The CREATE_TIME column
of the INFORMATION_SCHEMA.PARTITIONS table now shows the correct partition creation time for
a partition of partitioned InnoDB tables.
The UPDATE_TIME column of the INFORMATION_SCHEMA.TABLES table now shows when a
partitioned InnoDB table was last updated by an INSERT, DELETE, or UPDATE. The UPDATE_TIME
column of the INFORMATION_SCHEMA.PARTITIONS table now shows when a partition of a
partitioned InnoDB table was last updated. (Bug #69990, Bug #17299181)
• InnoDB; Microsoft Windows: General tablespaces created on Windows using a relative data file
path could not be opened on Unix-like systems. InnoDB failed to convert the backslash (“\”) directory
separator that is used in the Windows version of the relative data file path. (Bug #20555168)
• InnoDB; Microsoft Windows: During shutdown on Windows, the listener object in
handle_shutdown() was freed while the listener was running, resulting in an exception in
buf_pool_from_bpage(). (Bug #20421223)
• InnoDB; Microsoft Windows: On Windows, asynchronous I/O requests remained waiting after
InnoDB initialization was aborted. (Bug #19363615)
• InnoDB: With innodb_strict_mode=OFF, a CREATE TEMPORARY TABLE ...
ROW_FORMAT=Compressed TABLESPACE=innodb_file_per_table DATA DIRECTORY ...
statement raised an assertion. The DATA DIRECTORY clause is not supported with temporary tables
and should be ignored. (Bug #21324507, Bug #77495)
• InnoDB: The btr_search_drop_page_hash_index function dereferenced the adaptive hash
index block before acquiring a latch, which could result in a race condition. (Bug #21310520)
• InnoDB: A regression introduced in MySQL 5.7.2 caused an innochecksum-related memory leak.
(Bug #21255718)
• InnoDB: The records_in_range function returned a constant value for spatial indexes. (Bug
#21245805, Bug #77332)
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MySQL 5.7 Release Notes
• InnoDB: In some cases, memory was not properly allocated for rw_lock_t instances. (Bug
#21242541)
• InnoDB: SHOW ENGINE INNODB STATUS no longer reports mutex metrics. Mutex metrics are now
reported by SHOW ENGINE INNODB MUTEX. (Bug #21238953, Bug #77314)
References: See also: Bug #21052754, Bug #21266784.
• InnoDB: Functionality required to build adaptive hash indexes on field prefixes was reintroduced to
improve sequential insert performance. The functionality was removed in MySQL 5.7.2 by the fix for
Bug #21198396. (Bug #21198396, Bug #77246)
• InnoDB: When defining buf_block_t, a lock and a mutex were often accessed in the same
vicinity, which could cause unintended cache line sharing. (Bug #21153684)
• InnoDB: The ib_cursor_moveto function did not accept a search tuple with fewer fields than are
defined for the index. (Bug #21121197, Bug #77083)
• InnoDB: The ib_table_truncate function failed to release a transaction, resulting in a hang on
server shutdown. (Bug #21121164, Bug #77084)
• InnoDB: The ib_open_table_by_id function passed an incorrect argument to
dict_table_open_on_id. (Bug #21121084, Bug #77100)
• InnoDB: On Unix-like platforms, os_file_create_simple_no_error_handling_func and
os_file_create_func opened files in different modes when innodb_flush_method was set to
O_DIRECT. (Bug #21113036, Bug #76627)
• InnoDB: A cascade operation resulted in a duplicate entry error in FTS_DOC_ID_INDEX. The same
document ID was used by two cascade operations. (Bug #21111301, Bug #77087)
• InnoDB: Starting the server with an invalid innodb_data_file_path setting did not produce a
sufficiently informative error message. (Bug #21103446, Bug #77056)
• InnoDB: A regression introduced in MySQL 5.7.5 caused sorting to be skipped when rebuilding a
table after dropping a single-column primary key. (Bug #21103101)
• InnoDB: Opening a foreign key-referenced table with foreign_key_checks enabled resulted
in an error when the table or database name contained special characters. (Bug #21094069, Bug
#77043)
• InnoDB: The page_zip_verify_checksum function returned false for a valid compressed page.
(Bug #21086723)
• InnoDB: DDL operations for tablespaces could fail to implicitly commit the current transaction. (Bug
#21081898)
• InnoDB: The rollback of a partially completed transaction containing more than one update
to a spatial index raised an assertion in row_ins_sec_index_entry_by_modify(). (Bug
#21076238)
• InnoDB: In the case of a lock conflict, shutdown could hang waiting for asynchronous rollback to
finish. (Bug #21075892)
• InnoDB: To avoid conflicts with implicitly created file-per-table tablespaces, CREATE
TABLESPACE ... ADD DATAFILE no longer supports creation of tablespace data files in
subdirectories under the MySQL data directory (datadir). Additionally, the data file path specified
in a CREATE TABLESPACE ... ADD DATAFILE statement must be an existing directory. InnoDB
no longer creates missing directories for CREATE TABLESPACE ... ADD DATAFILE statements.
(Bug #21068487, Bug #77002)
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MySQL 5.7 Release Notes
• InnoDB: SHOW ENGINE INNODB MUTEX functionality, which was removed in MySQL 5.7.2, was
revised and added back. Mutex statistics collection can now be configured dynamically using the
following options:
• To enable the collection of mutex statistics, run:
SET GLOBAL innodb_monitor_enable='latch';
• To reset mutex statistics, run:
SET GLOBAL innodb_monitor_reset='latch';
• To disable the collection of mutex statistics, run:
SET GLOBAL innodb_monitor_disable='latch';
For more information, see SHOW ENGINE Syntax.
Sync debug checking for the InnoDB storage engine, previously defined under UNIV_SYNC_DEBUG,
is now defined under UNIV_DEBUG and is available when debugging support is compiled in using the
WITH_DEBUG CMake option. When debugging support is compiled in, InnoDB sync debug checking
is controlled by the innodb_sync_debug configuration option. (Bug #21052754)
• InnoDB: A tablespace opened locally by a truncate routine was not closed in protected mode. (Bug
#21046968)
• InnoDB: An assertion was raised when truncation logic identified inactive undo tablespaces as
candidates for undo log truncation. Some undo tablespaces were left inactive when the number of
available undo tablespaces exceeded the number of undo logs. (Bug #21046781)
• InnoDB: At startup, InnoDB updated the SYS_DATAFILES internal system table with the
space_id and path of each system tablespace file even though a record was already present and
SYS_DATAFILES.PATH matched the current value. (Bug #21044191)
• InnoDB: In Windows debug builds, an innodb_flush_method setting of normal or unbuffered
raised an assertion. (Bug #20981684)
• InnoDB: Transactions could be subjected to rollback while performing DDL operations. The
transactions were not marked as DDL transactions, and TRX_FORCE_ROLLBACK_DISABLE was not
set. (Bug #20979020)
• InnoDB: An ALTER TABLE ... IMPORT TABLESPACE operation on a table with prefix index failed
with a schema mismatch error. (Bug #20977779, Bug #76877)
• InnoDB: Initializing the database with an innodb_page_size setting of 64K and a system
tablespace data file size less than 12MB raised an assertion. With an InnoDB page size of 64KB,
the first system tablespace data file (ibdata1) was not large enough to contain the doublewrite
buffer blocks (block1 and block2). To ensure that the doubwrite buffer blocks fit within the first
system tablespace data file, a minimum data file size is now enforced. If innodb_page_size
is less than or equal to 16KB, the minimum data file size for the first system tablespace data
file (ibdata1) is 3MB. For innodb_page_size=32k, the minimum data file size is 6MB. For
innodb_page_size=64k, the minimum data file size is 12MB. (Bug #20972309)
• InnoDB: Full-text search operations between tables related by a foreign key constraint were not
properly cascaded during iterative DML cascading operations. (Bug #20953265, Bug #76817)
• InnoDB: In MySQL 5.7.2, 32 of 128 undo logs (rollback segments) were reserved as non-redo
undo logs for temporary table transactions. With one of the remaining undo logs always allocated
to the system tablespace, 95 undo logs remained available for allocation to the system tablespace
or separate undo tablespaces. This change effectively reduced the innodb_undo_tablespaces
maximum limit to 95. In other words, a limit of 95 available undo logs also limited the maximum
number of undo tablespaces to 95. In MySQL 5.7.8, the innodb_undo_tablespaces maximum
value is officially reduced to 95. (Bug #20938115)
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MySQL 5.7 Release Notes
• InnoDB: A memory leak occurred when a foreign key constraint object was loaded with the parent
table while the child table failed to load. The foreign key constraint object should only be loaded with
the child table. (Bug #20926253, Bug #21041449)
• InnoDB: Debug only code set m_prebuilt, which may affect in-place ALTER TABLE behaviour.
m_prebuilt to should not be used to store an intermediate value in debug-only code. (Bug
#20921940, Bug #76774)
• InnoDB: The definition of the fil_node_t data structure was moved from fil0fil.cc to
fil0fil.h so that diagnostic code outside that module can access information about files that
belong to a tablespace. (Bug #20886222, Bug #76694)
• InnoDB: Assertion code was revised to avoid compiler warnings that occurred when compiling
MySQL on OS X 10.10.2. (Bug #20883256, Bug #76690)
• InnoDB: After upgrading to MySQL 5.7.6 or later, restarting the server after truncating a table that
was originally created in MySQL 5.7.5 or earlier raised an “incorrect MERGE_THRESHOLD length in
SYS_INDEXES” error. A MERGE_THRESHOLD column was added to the internal SYS_INDEXES table
in MySQL 5.7.6. SYS_INDEXES records for tables that were not rebuilt or imported after upgrading
did not include the new column. The TRUNCATE TABLE operation updated the table's SYS_INDEXES
records to include the new column but set the MERGE_THRESHOLD value to NULL. (Bug #20882432)
• InnoDB: A failure to load a change buffer bitmap page during a concurrent delete tablespace
operation caused a server exit. (Bug #20878735)
• InnoDB: A shutdown hang occurred when an innodb_force_recovery setting of 3 or higher
prevented the rollback of transactions that were in an ACTIVE state. ACTIVE transactions are now
placed in XA PREPARE state in the main-memory data structure to allow shutdown to proceed
normally. The transactions are recovered as ACTIVE on the next restart and are rolled back unless
innodb_force_recovery is again set to 3 or higher. (Bug #20874411)
• InnoDB: If a server exit occurred during an XA ROLLBACK, the transaction was incorrectly recovered
in XA PREPARE state. As a result, subsequent XA COMMIT transactions were possible, which
would break ACID compliance and potentially cause corruption between indexes of a table. (Bug
#20872655, Bug #76672)
• InnoDB: A CREATE TABLESPACE operation raised a Valgrind error due to a memory leak in the
os_create_subdirs_if_needed function. (Bug #20865674)
• InnoDB: Calls to buf_page_print() were removed to avoid filling mysql-test-run logs with
InnoDB page dumps. Page dumps related to file I/O are still printed. (Bug #20863042)
• InnoDB: CREATE TABLESPACE failed to move internal tablespace files to a reserved name
space that starts with an innodb_ prefix, permitting internal tablespace files to be dropped. (Bug
#20840368, Bug #76603)
• InnoDB: A TRUNCATE TABLE operation on a general tablespace table with a full-text search index
raised an assertion. (Bug #20834483)
• InnoDB: An assertion was raised on shutdown due to XA PREPARE transactions holding explicit
locks. (Bug #20816223, Bug #76567)
• InnoDB: The fts_print_doc_id function printed too much debug information in debug builds.
fts_enable_diag_print is now used instead. (Bug #20811125)
• InnoDB: After a failed DROP TABLE operation, the purge background thread asserted while
attempting to access an index page of the table. Purge should not attempt to clean a table that is
marked as corrupt. Purge now checks for a corrupt primary index. (Bug #20789078, Bug #75913)
• InnoDB: A checksum mismatch error on a crc32 checksum was encountered when restarting
the server on a data file copied from a machine with a different endianness. The crc32 checksum
should be recognized regardless of the native byte order of the system where the checksum was
generated. (Bug #20783098, Bug #76375)
111
MySQL 5.7 Release Notes
• InnoDB: An ALTER TABLE ... DROP INDEX operation on a table with foreign key dependencies
raised an assertion. (Bug #20768847)
• InnoDB: An assertion was raised when InnoDB attempted to dereference a NULL foreign key
object. (Bug #20762798)
• InnoDB: An ALTER TABLE operation raised an assertion due a regression introduced in MySQL
5.7.6 with the introduction of native partitioning support for general tablespaces. (Bug #20759613)
• InnoDB: In some instances, functions that call DBUG_ENTER did not call DBUG_RETURN. (Bug
#20753620, Bug #76447)
• InnoDB: A regression of the trx_is_started function in MySQL 5.7.6 caused a shutdown hang.
(Bug #20744155)
• InnoDB: The MeCab full-text plugin parser failed to handle an out-of-memory exception. (Bug
#20742590)
• InnoDB: An assertion was raised during a rollback operation due to a record the was incorrectly
undelete-marked. (Bug #20734998)
• InnoDB: An assertion was raised in a debug build when an ALTER TABLE operation invoked
obsolete foreign key code while attempting to create an optimized temporary table as part of an
optimizer plan. Temporary tables do not support foreign keys. Invocation of foreign key code is now
blocked for optimized temporary tables. (Bug #20730289)
• InnoDB: An INSERT operation raised an assertion. The calculation that determines the number of
extents to reserve when storing a BLOB did account for compressed pages. (Bug #20713559)
• InnoDB: Missing brackets in the fsp_flags_is_valid function could result in a failure to
recognize a corrupted data file. (Bug #20671465)
• InnoDB: A query that used a percentage character '%' as the last character in a query token raised
a full-text parser plugin assertion. Full-text parser plugins created using the full-text parser plugin
framework now ignore the '%' character if specified as the first or last character in a query token.
Using the '%' character as the first character in a query token is not permitted by the internal SQL
parser. Using the '%' character as last character in a query token is reserved for prefix matching.
(Bug #20668156)
• InnoDB: The INFORMATION_SCHEMA.FILES table now reports metadata for all
InnoDB tablespace types including file-per-table tablespaces, general tablespaces,
the system tablespace, temporary table tablespaces, and undo tablespaces (if
present). System tablespace and temporary table tablespace metadata is no
longer reported by the INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES and
INFORMATION_SCHEMA.INNODB_SYS_DATAFILES tables. However, these tables continue to
provide metadata for file-per-table and general tablespaces. (Bug #20660744, Bug #21086257, Bug
#77032, Bug #76182)
• InnoDB: The InnoDB full-text search feature with the MeCab parser plugin would print an empty
error message. (Bug #20651493, Bug #76164)
• InnoDB: Importing a tablespace with a full-text index resulted in an assertion when attempting to
rebuild the index. (Bug #20637494)
• InnoDB: A DML operation raised an assertion in btr_estimate_n_rows_in_range(). The
assertion code was too strict. (Bug #20618309)
• InnoDB: Defining a user-created FTS_DOC_ID column as a primary key produced incorrect full-text
search relevancy rankings. (Bug #20597981)
• InnoDB: During a table import operation, an INSERT failed with a duplicate key error on an
AUTO_INCREMENT column due to an incorrectly initialized AUTO_INCREMENT value. (Bug
#20597821, Bug #76037)
112
MySQL 5.7 Release Notes
• InnoDB: After dropping a full-text search index, the hidden FTS_DOC_ID and FTS_DOC_ID_INDEX
columns prevented online DDL operations. (Bug #20590013, Bug #76012)
• InnoDB: An assertion was raised on server startup when InnoDB tried to create a temporary file in a
non-existent temporary directory (tmpdir) while in read-only mode. (Bug #20578834)
• InnoDB: The innodb_checksum_algorithm strict_* settings (strict_none,
strict_innodb, and strict_crc32) caused the server to halt when InnoDB encountered a valid
but non-matching checksum. For example, with innodb_checksum_algorithm=strict_crc32,
a valid innodb checksum would cause the server to halt. Now, instead of halting the server, InnoDB
only prints an error message. (Bug #20568464)
• InnoDB: After moving the MySQL data directory and modifying the datadir configuration
parameter to point to the new location, tables stored in general tablespaces failed to open because
the tablespace data file could not be found. To address this problem, CREATE TABLESPACE ...
ADD DATAFILE now creates an isl file in the MySQL data directory when a general tablespace
data file is created outside of the MySQL data directory. Also, the fil_ibd_open function now
searches for general tablespaces in the same way that it searches for file-per-table tablespaces.
(Bug #20563954)
• InnoDB: General tablespaces now support partitioned InnoDB tables, and individual partitions and
subpartitions can now be assigned to a general tablespace. SHOW CREATE TABLE output was
revised to include quotes around the tablespace identifier. (Bug #20554858, Bug #20588947)
• InnoDB: An ALTER TABLE operation that added a spatial index caused the server to exit. (Bug
#20547644)
• InnoDB: Assertion code which checks for the lowest possible page number for a tablespace did not
account for general tablespaces. (Bug #20544581, Bug #20810627)
• InnoDB: The InnoDB memcached plugin handled unsigned NOT NULL integer columns incorrectly.
Thanks to Piotr Jurkiewicz for the patch. (Bug #20535517, Bug #75864)
• InnoDB: The following changes were implemented for full-text index auxiliary tables:
• If the primary table is assigned to a general tablespace, full-text auxiliary tables are created in the
same general tablespace.
• Full-text auxiliary tables are created with the same row format as the primary table.
• If the primary table was created in a location outside of the data directory using the DATA
DIRECTORY clause, full-text auxiliary tables are created in the same location as the primary table.
(Bug #20527217, Bug #75869)
• InnoDB: The memcached set command permitted a negative expire time value. Expire time is
stored internally as an unsigned integer. A negative value would be converted to a large number
and accepted. The maximum expire time value is now restricted to INT_MAX32 to prevent negative
expire time values. (Bug #20478242, Bug #75790)
• InnoDB: An interrupted ALTER TABLE operation that rendered a child table unavailable caused an
error and debug assertion after crash recovery, when the ALTER TABLE operation on the parent
table detected that the foreign keys of the parent table could not be loaded. The debug assertion was
removed and the error was replaced by a warning. (Bug #20476395)
References: This issue is a regression of: Bug #19267051.
• InnoDB: In debug builds, enabling the btr_cur_limit_optimistic_insert_debug flag raised
a deadlock exception in the change buffer clustered index. (Bug #20459905, Bug #75736)
• InnoDB: A warning message is now printed if DB_TRX_ID stored in a record is found to be greater
than max_trx_id. In debug builds, an assertion is raised. (Bug #20445525)
113
MySQL 5.7 Release Notes
• InnoDB: Estimates for the number of records in a range for a given dataset could differ depending
on the page size. (Bug #20427694)
• InnoDB: SHOW ENGINE INNODB STATUS output showed negative reservation and signal count
values due to a counter overflow error. (Bug #20417397)
• InnoDB: Failure to check the status of a cursor transaction read-only option before reusing the
cursor transaction for a write operation resulted in a server exit during a memcached workload. (Bug
#20391552)
• InnoDB: An assertion was raised in a debug build when populating a spatial index during an
ALTER TABLE operation. The size of data tuples for compressed rows is calculated in the
rec_get_converted_size_comp_prefix_low function. Debug code within the function did
not account for the spatial index or the DATA_SYS_CHILD data type in the node pointers. (Bug
#20372749)
• InnoDB: CHECK TABLE returned a “wrong count” error for tables with spatial indexes. (Bug
#20313067)
• InnoDB: MDL locks taken by memcached clients caused a MySQL Enterprise Backup FLUSH
TABLES WITH READ LOCK operation to hang. (Bug #20275612)
• InnoDB: An embedded MySQL server failed to start with innodb_undo_tablespaces=2. The
server was unable to locate undo tablespaces that were created when the MySQL instance was
initialized. For embedded MySQL installations, the innodb_undo_directory default value
of “.” may not be the same directory as the MySQL data directory. To address this problem,
innodb_undo_directory is now NULL by default, requiring that a path be specified. If a path is
not specified, undo tablespaces are created in the MySQL data directory, as defined by datadir.
A workaround for pre-MySQL 5.7.8 embedded installations is to define an absolute path for
innodb_undo_directory. (Bug #20023425)
• InnoDB: A DML operation raised an assertion in file lock0lock.cc. A session holding an exclusive
row lock on a clustered index page initiated a page reorganization while another session waited for
a lock on the same row. The page reorganization changed the lock order, causing an assertion in
lock_rec_add_to_queue(). (Bug #20005279)
• InnoDB: A DROP DATABASE operation raised an assertion. (Bug #19929435)
• InnoDB: InnoDB failed to open a tablespace after the data directory location of the tablespace
was changed from a relative path to a full path. InnoDB failed to recognize that the relative path,
which remained embedded in the data dictionary, pointed to the same data file as the full path. (Bug
#19896685)
• InnoDB: A TRUNCATE TABLE operation appeared to hang when run in parallel with a read-write
workload. (Bug #19873470, Bug #74312)
• InnoDB: The sorted index build feature introduced in MySQL 5.7.5 caused a performance regression
when adding an index to a small table. The regression was due to excessive flushing triggered by a
forced checkpoint that occurs after the sorted index build. (Bug #19865673, Bug #74472)
• InnoDB: Updates to indexed columns could be slower in MySQL 5.7.5 and higher. In preMySQL 5.7.5 releases, InnoDB reserves 1/16 of the space in clustered index pages for future
inserts and updates. This behaviour changed in MySQL 5.7.5 with the introduction of the
innodb_fill_factor option. With innodb_fill_factor=100, B-tree index pages were
completely filled during sorted index builds, and subsequent updates to index pages resulted in page
splitting. To restore pre-MySQL 5.7.5 behavior, the default setting of innodb_fill_factor=100
now leaves 1/16 of the space in clustered index pages free for future index growth. (Bug #19821087,
Bug #74325)
• InnoDB: The ha_innobase::index_flags function returned invalid flags for spatial indexes.
(Bug #19473391)
114
MySQL 5.7 Release Notes
• InnoDB: An index record was not found on rollback due to inconsistencies in the purge_node_t
structure. The inconsistency resulted in warnings and error messages such as “error in sec index
entry update”, “unable to purge a record”, and “tried to purge sec index entry not marked for
deletion”. (Bug #19138298, Bug #70214, Bug #21126772, Bug #21065746)
• InnoDB: The ut_when_dtor struct, added in MySQL 5.7 to address a Valgrind issue, was removed
to reduce code complexity. (Bug #18309926)
• InnoDB: An INSERT operation raised an assertion when the transaction mode was modified after
the transaction started. (Bug #15866285)
• InnoDB: Queries that use both UNION and UNION ALL and disable the index would cause an
assertion due to duplicate B-tree values. (Bug #76439, Bug #20752543)
• InnoDB: In debug builds, attempting to create a spatial index after dropping
the mysql.innodb_table_stats table raised an assertion in the
btr_cur_open_at_rnd_pos_func function. (Bug #76437, Bug #20753642)
• InnoDB: Transaction objects were passed to optimized temporary table APIs, causing an assertion.
Optimized temporary tables, which do not support rollback and are not shared across connections,
should ignore the transaction objects. (Bug #76415, Bug #20748479)
• InnoDB: When innodb_thread_concurrency=1, queries on optimized temporary tables caused
other sessions to hang. Queries on optimized temporary tables should not increment the number of
active threads. (Bug #76346, Bug #20762059)
• Partitioning: During execution of correlated subqueries, the server reinitialized a scan executed on
the same table without ending the previous scan. (Bug #20949314, Bug #76810)
• Partitioning: CREATE TABLE statements that used an invalid function in a subpartitioning
expression did not always fail gracefully as expected. (Bug #20310212)
• Partitioning: For an ordered index scan over multiple partitions, MySQL performs a merge sort
across them using a priority queue whose entries hold pointers to buffers containing fetched
rows. When all rows from all partitions are fetched, this queue is now empty. When this occurred,
subsequent attempts to fetch rows were done by passing a null buffer pointer, which caused the
server to fail. This could manifest itself when executing HANDLER ... READ ... PREV against
a partitioned table. Now in such cases this pointer holds NO_CURRENT_PART_ID so that the
partitioning handler is aware that the queue is empty. (Bug #20270687)
• Partitioning: REPAIR TABLE ... QUICK could fail when used with multiple partitioned tables.
(Bug #76154, Bug #20647894)
• Partitioning: In certain cases, ALTER TABLE ... REBUILD PARTITION was not handled
correctly when executed on a locked table. (Bug #75677, Bug #20437706)
• Replication: When using multiple replication channels, issuing RESET SLAVE on a non-default
replication channel removes the channel, whereas issuing RESET SLAVE on the default replication
channel does not remove the channel, as it always exists. In previous versions, this meant that the
default replication channel did not correctly reset some configuration and status parameters. The fix
ensures that issuing RESET SLAVE on the default replication channel resets all parameters. (Bug
#21107331, Bug #21111229, Bug #77086)
• Replication: Repeatedly checking for ERR_LOCK_WAIT_TIMEOUT (as done, for example by
repeatedly executing SHOW SLAVE STATUS) during a prolonged write lock on a table led to an
assert. (Bug #21095969)
• Replication: SHOW BINLOG EVENTS was not showing the correct statement for XA COMMIT ...
ONE PHASE. Although the event was logged and replicated correctly, SHOW BINLOG EVENTS was
showing an incorrect statement when handling the event. The fix ensures that the statement is
correctly displayed. (Bug #21053526)
115
MySQL 5.7 Release Notes
• Replication: When changing gtid_mode online, if autocommit was set to 0 and a set
gtid_next=UUID:NUMBER statement had been issued, then changing gtid_mode was not
being blocked. The fix ensures that variables which can only be set outside transaction context can
now only be set if the thread does not own a GTID and does not hold anonymous ownership. This
changes the behavior of these variables:
• enforce_gtid_consistency
• gtid_mode
• gtid_purged
• session_track_gtids
(Bug #20865683)
• Replication: mysqlbinlog would apply any rewrite rules before applying the database filter. This
meant that in cases when statement-based replication transactions were mixed with row-based
replication transactions only one or the other type of transaction would be output. The fix changes
the behavior so that the rewrite rules also apply to the USE db_name clause, rewriting the database
specified by db_name according to the setting of the --rewrite-db parameter. This makes
it possible to use the --database option on the query and row events. In addition, it removes
the suppression of the USE db_name statement and ensures that the rewrite is done before the
database filter. (Bug #20810442)
• Replication: Row unpacking did not function correctly in some cases when running the server with
binlog_row_image set to minimal. (Bug #20468712)
• Replication: When slaves, and especially semisynchronous replication slaves, connected to
a master there was a chance they could encounter a SLAVE HAS MORE GTIDS THAN THE
MASTER HAS error. During connection the slave sends all replicated GTIDs to the master, and the
master checks if all the GTIDs matching its server_uuid are included in its gtid_executed
GTID set. There was a chance that a GTID was already in the slave's gtid_executed GTID set,
but not in the master's gtid_executed GTID set. This was due to the GTID being added into
gtid_executed after it was added to the binary log, meaning it was possible that a transaction
had been replicated and applied on the slave, but not committed on the master yet. The fix ensures
that the master checks if all GTIDs are in the union of gtid_executed and gtid_owned. (Bug
#20464737)
• Replication: A replication slave running with a gtid_mode other than OFF, log_bin=OFF and
relay_log_info_repository=TABLE was consuming the GTID of a transaction prematurely
when applying a transaction that spanned across distinct relay log files. This was caused when the
slave SQL thread was flushing the relay log information to the mysql.slave_relay_log_info
table while in the middle of a transaction, or immediately after the GTID of a transaction, because of
the rotation of the relay log. The fix skips saving the gtid_state for operations that save the relay
log information to the mysql.slave_relay_log_info table. (Bug #20451386)
• Replication: When gtid_mode=ON, issuing a SET gtid_next='UUID:NUMBER' statement and
then issuing a statement that caused an error, such as CREATE..SELECT, led to an assertion failure
on COMMIT. This was due to gtid_next being incorrectly set to undefined for implicitly committing
statements, even if the statement failed with an error before the implicit commit happened. (Bug
#20343644, Bug #20444828)
• Replication: If a slave was restarted with --relay-log-recovery enabled and the initialization
of the default replication channel had failed, a slave could refuse to start or cause an assert in debug
mode. (Bug #20191813, Bug #20236305)
• Replication: When using RESET MASTER, the GTID state (gtid_executed and gtid_purged)
is reset. On a server with log_bin=OFF, using RESET MASTER fails because the binary log is not
enabled. However, since MySQL 5.7.5, GTIDs can be enabled even when the binary log is disabled.
So in this case there was no way to reset the GTID state. The fix ensures that RESET MASTER can
116
MySQL 5.7 Release Notes
be executed on a server with GTIDs enabled and log_bin=OFF, enabling you to reset the GTID
state. (Bug #19706455)
• Replication: If statement based logging was in use, when updating multiple tables in a single
statement, a single transaction could be logged as two different transactions. This was due to the
binary logging process not properly identifying statements which were operating over transactional
tables. The fix ensures that they are correctly identified, even if such statements do not change the
contents of the tables. (Bug #16621582, Bug #21349028)
• Replication: When starting more than one instance of mysqld on the same host at the same time,
the instances could get the same server_uuid. The fix uses settings unique to each started
mysqld instance to ensure that each gets a unique UUID. (Bug #16459136)
• Replication: Some replication thread statuses were not being shown in the PROCESSLIST_INFO
column of the threads table. (Bug #77115, Bug #21127308)
• Replication: In MySQL 5.7.7 and earlier, GTIDs were automatically disabled whenever -initialize or --bootstrap were enabled. In MySQL 5.7.8 and later GTIDs are not disabled
when --initialize or --bootstrap are enabled. (Bug #76884, Bug #20980271)
• Replication: When using mysql-test-run.pl with the --ps-protocol option to run a test
against a server with log_bin=OFF, setting gtid_next and then executing a DDL statement
caused an error. This was due to the DDL statement not being correctly logged to consume the GTID
specified when setting gtid_next. (Bug #76820, Bug #20954452)
• Replication: When log_bin=ON, if a read-only XA transaction was prepared but had an empty
body, a subsequent XA ROLLBACK caused an assertion. (Bug #76734, Bug #20902763)
• Replication: explicit_defaults_for_timestamp has been changed from a global variable
to a global and session variable, and the session variable is now replicated. This means that you
can change the variable and still be guaranteed that every statement uses the same value for the
variable on master and slave, even if the variable is not changed synchronously on master and
slave. (Bug #76657, Bug #20866059)
• Replication: When a slave was stopped, replication_applier_status_by_worker showed
worker_id as 1 and did not show the correct number. (Bug #76637, Bug #20857660)
• Replication: Setting SESSION.GTID_NEXT=default immediately
after setting SESSION.GTID_NEXT='ANONYMOUS' causes an
ER_CANT_SET_GTID_NEXT_WHEN_OWNING_GTID error, but this also changes the gtid_next
type from ANONYMOUS to AUTOMATIC, meaning that the next transaction could potentially cause an
GTID_NEXT->TYPE != AUTOMATIC_GROUP || THD->OWNED_GTID.IS_EMPTY() assertion. To
avoid this possibility, the fix ensures that setting SESSION.GTID_NEXT=default does not change
the gtid_next type if it could cause an error. (Bug #76434, Bug #20753378)
• Replication: Additional replication channels could not be added if the server had been started with
server_id=0, the default. The fix ensures that a replication slave checks the server_id is greater
than 0 when CHANGE MASTER TO has been issued before continuing with the initialization of a
channel. (Bug #76432, Bug #20753463, Bug #20712720)
• Replication: When a server was configured with gtid_mode=ON, log-bin=OFF, and
with autocommit enabled, during commit it was possible to encounter an ASSERTION
`IS_STARTED()' FAILED error. This was possible when an applier thread committed a
transaction's GTID into the gtid_executed table before transaction prepare when binary logging
was disabled, or binary logging was enabled and log_slave_updates was disabled. The cause
was that when the server was saving a transaction's GTID into the gtid_executed table, the
calculated transaction context could be committed during the save phase when autocommit was
enabled. The fix ensures that the transaction context is calculated after saving the GTID's state, and
then commit is executed on any remaining transactions. (Bug #76425, Bug #20748570)
• Replication: When using row-based logging with autocommit disabled and
GTID_MODE=OFF_PERMISSIVE, if a transaction started with a CREATE TEMPORARY
117
MySQL 5.7 Release Notes
TABLE statement, then regardless of whether the table was transactional or nontransactional, the transaction began an automatic GTID violating transaction. However, if
GTID_NEXT='UUID:NUMBER' was issued immediately after executing the CREATE TEMPORARY
TABLE statement, which sets gtid_next type to GTID_GROUP, upon committing the transaction,
a check for possible violation of GTID consistency was causing an assertion failure because the
gtid_next type had been changed from AUTOMATIC_GROUP to GTID_GROUP.
The fix ensures that transactions with an empty owned GTID correctly check if they break
GTID consistency. As part of this fix, it was found that when autocommit was disabled, the
statement CREATE TEMPORARY TABLE did not start a transaction, so immediately setting
GTID_NEXT='UUID:NUMBER' could not cause an error. The fix ensures that when autocommit
is disabled, executing CREATE TEMPORARY TABLE or DROP TEMPORARY TABLE starts a
transaction, regardless of the state of log_bin, binlog_format and whether a transactional or
non-transactional storage engine is in use. This makes the behavior consistent, but is a change in
logging when log-bin=OFF. (Bug #76416, Bug #20748502)
• Replication: When using GTIDs with log-bin=OFF, a combination of statements which included a
BINLOG statement executing a Format_description_log_event would cause an assertion. The
reason was that the server would run the routine to handle the end of a GTID violating transaction,
which was incorrect because when --log-bin=OFF the transaction should not have been handled
as an offending transaction. The fix ensures that before the compatibility testing, the state of
log_bin is checked. If log_bin=OFF, then the compatibility checks are skipped. This makes
the server not activate flags that would then trigger the incorrect run of the routine to handle GTID
violating transactions that ultimately resulted in an assertion. (Bug #76406, Bug #20743468)
• Replication: When binary logging was enabled, using stored functions and triggers resulting in a
long running procedure that inserted many records caused the memory use to increase rapidly. This
was due to memory being allocated per variable. The fix ensures that in such a situation, memory is
allocated once and the same memory is reused. (Bug #75879, Bug #20531812)
• Replication: If an error occurred when using a multi-threaded slave, issuing a CHANGE MASTER
TO statement which resulted in an ER_MTS_CHANGE_MASTER_CANT_RUN_WITH_GAPS
error, and then issuing RESET SLAVE, made it impossible to change master due to repeated
ER_MTS_CHANGE_MASTER_CANT_RUN_WITH_GAPS errors. Running the debug version of mysqld
caused an unexpected exit in this case. The fix ensures that the recovery process for multi-threaded
slaves avoids this. (Bug #75574, Bug #20411374)
• Replication: When using semisynchronous replication performance was degrading when the
number of threads increased beyond a certain threshold. To improve performance, now only
the thread which is committing is responsible for deleting the active transaction node. All other
operations do not touch this active transaction list. (Bug #75570, Bug #20574628)
• Replication: When gtid_executed_compression_period is set to a number greater
than 0, there is a thread that wakes up after every number of transactions specified
by gtid_executed_compression_period to perform range compression on the
mysql.gtid_executed table. There was a small chance that the thread would miss a signal
and not wake up, so that one pass of the compression algorithm would be missed and the table
left uncompressed. The fix ensures that the thread wakes up consistently. (Bug #75014, Bug
#20104307)
• Replication: Using mysqlbinlog to process log events greater than 1.6GB failed with an out of
memory error. This was caused by an internal error converting the length variable. The fix upgrades
the length variable to avoid overflow in both encoding and decoding functions. (Bug #74734, Bug
#20350989)
• Replication: Setting gtid_next inside a stored procedure and committing an empty transaction
caused an error. This was due to the empty transaction not being correctly logged to consume the
GTID specified by setting gtid_next. (Bug #74253, Bug #19774317)
118
MySQL 5.7 Release Notes
• Replication: Some messages that were meant to be printed when log_warnings was greater than
1 started appearing in the error log. The information regarding the multi-threaded applier in particular
was too verbose and much of this information was very technical and development oriented. The fix
ensures that these messages are not logged. (Bug #74203, Bug #19729278)
• Replication: When using a multi-threaded slave with slave_preserve_commit_order=1, certain
combinations of transactions being applied in parallel could cause a deadlock and stop the slave
responding. The fix introduces a check for such deadlocks, so that when a transaction needs to wait
for another transaction to release a row lock, InnoDB checks if there is a deadlock caused by the
commit order. If it finds a deadlock caused by the commit order, it sets a deadlock flag for the slave
worker which is holding the row lock. Then the worker rolls back its transaction and tries again. (Bug
#74177, Bug #20136704)
• Replication: When relay_log_recovery is set, the error log entry that reports the new recovery
positions has been extended to also report the old relay log positions. (Bug #74089, Bug #21305976)
• Replication: When a master with --binlog_checksum=none and --gtid-mode=ON was
replicating to a slave with --binlog_checksum=crc32, restarting the slave's SQL thread caused
an Event crc check error. This was due to the Format_description_log_event from
the master not being correctly found in existing relay logs after restarting the slave's SQL thread.
The fix ensures that the Previous_gtids_log_event is correctly skipped and that the correct
Format_description_log_event is found in existing relay logs after restarting the slave's SQL
thread. (Bug #73806, Bug #20644100, Bug #76746, Bug #20909880)
• Replication: When gtid_mode=on, GTIDs are automatically added to the
mysql.gtid_executed table. If a GTID was manually inserted into the mysql.gtid_executed
table and then automatic update inserted the same GTID, the server crashed. Manually inserting
GTIDs into mysql.gtid_executed is an unsupported operation, but this fix ensures that the server
does not crash in such a situation. (Bug #73601, Bug #19451053)
• Replication: When using GTIDs, a multi-threaded slave which had relay_log_recovery=1 and
that stopped unexpectedly could encounter a relay-log-recovery cannot be executed
when the slave was stopped with an error or killed in MTS mode error upon
restart. The fix ensures that the relay log recovery process checks if GTIDs are in use or not. If
GTIDs are in use, the multi-threaded slave recovery process uses the GTID protocol to fill any
unprocessed transactions. (Bug #73397, Bug #19316063)
• Replication: When master_info_repository=TABLE the receiver thread stores received event
information in a table. The memory used in the process of updating the table was not being freed
correctly and this could lead to an out of memory error. The fix ensures that after an event is flushed
to the relay log file by a receiver thread, the memory used is freed. (Bug #72885, Bug #19390463,
Bug #69848, Bug #20124342)
• Replication: The status variables Rpl_semi_sync_master_net_wait_time and
Rpl_semi_sync_master_net_avg_wait_time were always 0 in MySQL 5.7.4 and later.
These variables are now deprecated and will be removed in a future version. (Bug #72627, Bug
#18750614)
• Replication: When two slaves with the same server_uuid were configured to replicate from a
single master, the I/O thread of the slaves kept reconnecting and generating new relay log files
without new content. In such a situation, the master now generates an error which is sent to the
slave. By receiving this error from the master, the slave I/O thread does not try to reconnect, avoiding
this problem. (Bug #72581, Bug #18731252)
• Replication: If a slave encountered a ER_NET_READ_INTERRUPTED or
ER_NET_WRITE_INTERRUPTED error while getting a timestamp or server ID from the master, setting
MASTER_HEARTBEAT_PERIOD and so on, the slave's receiver thread stopped. The fix ensures
that these errors are treated as transient network errors, and the slave receiver thread attempts to
automatically reconnect to the master in such a situation. (Bug #71374, Bug #18091217)
119
MySQL 5.7 Release Notes
• Replication: Using mysqlbinlog to replay a relay log which ended with GTID_LOG_EVENT could
cause the following error:
ERROR 1790 (HY000) @@SESSION.GTID_NEXT cannot be changed by a client that
owns a GTID. The client owns UUID:GTID. Ownership is released on COMMIT or
ROLLBACK.
If a relay log rotate happens (either through a receiver thread restart or after issuing the ROTATE
command) exactly after writing a GTID_LOG_EVENT, when replaying such a relay log's end
ROTATE_EVENT, it was mistakenly identified as being inside a transaction, whereas the transaction
was actually started after GTID_LOG_EVENT. This caused mysqlbinlog to append SET
@@SESSION.GTID_NEXT='AUTOMATIC', resulting in two GTID_NEXT statements one after the
other. The fix ensures that mysqlbinlog generates SET @@SESSION.GTID_NEXT='AUTOMATIC'
only outside of a transaction and when there has not been a previous GTID_LOG_EVENT.
Similarly, using mysqlbinlog to concatenate and replay a relay log which contained a partial
GTID transaction caused the above error. A relay log can contain a partial GTID transaction when
AUTO_POSITION is enabled if a receiver thread is restarted when it is in the middle of transferring
a transaction from a master. On restart the slave retrieves the full transaction again. In this case,
the first relay log contains a partial GTID transaction and the second relay log contains the full GTID
transaction again. When using mysqlbinlog to concatenate such a relay log, the partial transaction
was not being correctly detected and therefore a ROLLBACK was not being correctly generated. The
fix identifies partial GTID transactions using the format description event of the second relay log,
ensuring that a ROLLBACK is correctly added. (Bug #70711, Bug #17650326)
• Replication: The replication connection now sends the program_name attribute, “mysqld”, in line
with the behavior of other client connections. In addition, a _client_role attribute has been
added and is set to “binary_log_listener”, to clarify the replication connection's role, as well as the
_client_replication_channel_name attribute, which is set to the replication channel's name.
Similarly, mysqlbinlog now sets _client_role to “binary_log_listener”. These changes are
exposed through the session_connect_attrs Performance Schema table. (Bug #68782, Bug
#16555723)
• On platforms where char is unsigned, mysql_config_editor could fail to detect failed
operations. Affected platforms include ARM and PowerPC. (Bug #21355630)
• The Rewriter plugin linked against the mysys library, which is already linked into the server and
thus available at load time when the plugin is installed. (Bug #21255496)
• Memory leaks found by enabling AddressSanitizer were corrected in mysql, mysqlcheck,
mysqldump, mysqlshow, mysqlslap, mysqltest, mysql_client_test, mysql_upgrade, and
mysql_install_db. (Bug #21246627, Bug #21246842, Bug #21246964, Bug #21247377, Bug
#21250562, Bug #21250584, Bug #21250644, Bug #21250876, Bug #21250947, Bug #21253535,
Bug #21253653, Bug #21254060, Bug #21255860)
• Multiple definitions of key_memory_KEY_CACHE caused compilation failure when ASAN was
enabled. (Bug #21245718)
• For debug builds, failure of the range optimizer to properly propagate errors occurring during partition
pruning could raise an assertion. (Bug #21211492)
• A SET PASSWORD statement that failed with ER_MUST_CHANGE_PASSWORD could still change the
password_last_changed column for a row in the mysql.user table. (Bug #21192879)
• An optimizer hint assertion could be raised when a table was used in both parts of an INSERT
INTO ... SELECT statement. (Bug #21192857)
• The create_tmp_table() return value was not checked, which could lead to a server exit. (Bug
#21190532)
120
MySQL 5.7 Release Notes
• Incorrect cost calculation for the semi-join Duplicate Weedout strategy could result in a server exit.
(Bug #21184091)
• Some Valgrind warnings in Item_type_holder::join_types() were spurious and have been
silenced. (Bug #21156155)
References: This issue is a regression of: Bug #19471564.
• The optimizer hint parser could read freed memory. (Bug #21148405)
• For debug builds, VIRTUAL generated columns could be marked writable during read operations and
cause an assertion to be raised for partitioned tables. (Bug #21142905)
• For debug builds, a missing error test for full-text searches could cause an assertion to be raised.
(Bug #21140111)
• Outer references do not work as arguments to MATCH(), but the server did not properly detect them.
Now it does and raises an error. (Bug #21140088)
References: See also: Bug #20007383.
• EXPLAIN could raise an assertion trying to display very large full-text search rank values. (Bug
#21140067)
• For debug builds, full-text searches could raise an assertion if the optimizer tried to use a covering
index when that was not appropriate. (Bug #21140039)
• SHOW STATUS and SHOW VARIABLES failed to produce output if the server was started with the
Performance Schema disabled. (Bug #21139458)
• ST_Intersection() could produce areal and point intersection results, but was not able to
produce linear intersection results. (Bug #21109896)
• ALTER TABLE statements that defined a generated column using MATCH ... AGAINST in its
expression could raise an assertion. (Bug #21098119)
• The server could raise an assertion or produce an incorrect error message for inserts into a view if a
single table for insertion could not be identified. (Bug #21097485)
• open_files_limit could be set higher than permitted by the operating system. (Bug #21074643)
• systemd timeout logic could be triggered if InnoDB log rebuilding or recovery took too long.
Because the time this may take is unknown, systemd timeout during service start or stop is now
disabled. (Bug #21071740)
• Comparisons of table names in optimizer hints did not respect the value of the
lower_case_table_names system variable. (Bug #21056644)
• CMake configuration was adjusted to disable unnecessary warnings reported by Clang and display
them only if -DMYSQL_MAINTAINER_MODE=1 is used. (Bug #21041451)
• Multiple executions of a prepared SET statement that used a subquery could result in a server exit.
(Bug #20982756)
• With auto_generate_certs enabled, the server automatically created SSL files if any of ca.pem,
server-cert.pem, and server-key.pem were missing from the data directory. Now it creates
the files only if all of them are missing (the same test used by mysql_ssl_rsa_setup). (Bug
#20963082)
• The server compiled with Performance Schema support could not be started with
performance_schema=OFF due to a dependency on it for the sys schema, which expected to find
Performance Schema tables. The Performance Schema now creates its tables during startup even if
disabled. (Bug #20956599)
121
MySQL 5.7 Release Notes
• For CREATE TABLE ... SELECT, it was possible to assign values to generated columns in the
destination table. (Bug #20949226)
• The server could exit when the Performance Schema read thread status variables under load. (Bug
#20927157, Bug #20922218, Bug #21103103)
• CMake support was adjusted for the change of the -Wno-unused-local-typedefs option to Wno-unused-local-typedef in Clang 3.6. (Bug #20921370)
• For debug builds, XA PREPARE raised an assertion if a transaction contained at least one update
and none were InnoDB updates. (Bug #20920851)
• Using ST_Centroid() with a geometry collection containing an invalid polygon could cause a
server exit. (Bug #20918881)
• For small values of the read_rnd_buffer_size system variable, internal caching of temporary
results could fail and cause query execution failure. (Bug #20895852)
• Invalid memory pointer access could occur during access to the events_statements_history
Performance Schema table, resulting in a server exit. (Bug #20878306)
• For debug builds, passing EXPORT_SET() to VALIDATE_PASSWORD_STRENGTH() could raise an
assertion. (Bug #20863229)
• A failed FLUSH PRIVILEGES statement followed by statements to create or drop accounts could
cause a server exit. (Bug #20857652)
• Large values of the points_per_circle argument to the ST_Buffer_Strategy() function
could cause large amounts of memory to be used. To avoid inadvertent excessive memory
use, the maximum value of this argument is now constrained to be the value of the new
max_points_in_geometry system variable. This variable has default, minimum, and maximum
values of 65,536, 3, and 1,048,576, respectively. (Bug #20842030, Bug #21212788)
• For certain inputs, ST_Buffer() could raise an assertion. (Bug #20841874)
• An assertion could be raised if the server used a string column as the key of a temporary table. (Bug
#20835095)
References: This issue is a regression of: Bug #19695490.
• SHOW VARIABLES mutexes were being locked twice, resulting in a server exit. (Bug #20788853)
• ull2dec() was modified to avoid a problem with GCC 5 in optimized mode. (Bug #20768820)
• Using GCC 5, debug builds failed due to compiler warnings. (Bug #20768717)
• DDL operations on a server configured with InnoDB as read only caused a server exit due to invalid
memory access during error reporting. (Bug #20763179)
• ALTER TABLE could fail to prevent subqueries in the definition of generated columns, resulting in a
server exit. (Bug #20757211)
• Invalid use of the THD structure with generated columns could cause an assertion to be raised. (Bug
#20746926)
• Parser state was initialized incorrectly for parsing generated column expressions. (Bug #20745142)
• For large values of max_digest_length, the Performance Schema could encounter an overflow
error when computing memory requirements, resulting in a server exit. (Bug #20738072)
• Columns specified through JOIN ... USING or NATURAL JOIN that were resolved from a derived
table could raise an assertion. (Bug #20733540)
122
MySQL 5.7 Release Notes
• MySQL 5.7.6 restricted the list of symbols exported by the C client library. One of these
was mysql_get_parameters, but that is used by the DBD::mysql Perl module.
mysql_get_parameters is now exported. (Bug #20686665)
References: See also: Bug #18427840, Bug #20476596, Bug #20821550.
• Cleanup after a MATCH() operation could write to freed memory. (Bug #20685427)
• NDB could raise an assertion for failure to get the tablespace name when attempting to acquire a
metadata lock. (Bug #20676000)
• mysqlslap and mysql_client_test failed to use an SSL connection by default. (Bug
#20654023)
• The Spencer regex library used for the REGEXP operator could be subject to heap overflow in some
circumstances. (Bug #20642505)
• A missing error check after a call to find_field_in_tables() within the optimizer could cause
an assertion to be raised. (Bug #20615597)
• Optimization of x IN (SELECT y FROM DUAL WHERE ...) was treated the same as x IN
(SELECT y FROM DUAL), losing the WHERE clause and resulting in a server exit. (Bug #20615023)
• A buffer-overflow error could occur for mysqlslap during option parsing. (Bug #20605441)
• For debug builds, DROP DATABASE raised an assertion if there were non-database files in the
database directory. (Bug #20573701)
• For CREATE TABLE ... SELECT, an error occurred if a selected column was a generated column
that depended on a nonselected column. To handle this, the destination table does not preserve
information about whether selected columns are generated columns. (Bug #20566243)
• A user with an expired password could execute ALTER USER statements other than to assign a new
password. (Bug #20553132)
• An OpenSSL error queue associated with each thread was not freed on thread release, resulting in a
Valgrind error. (Bug #20551271)
• The property of whether a view is updatable was calculated when it was created. If the view referred
to another view that was dropped and recreated and the new definition of the referenced view had
different updatability than the original definition, that could affect the updatability of the referring view.
Not taking into account this change in updatability could cause an assertion to be raised. To avoid
this problem, the server now assesses updatability when reading a view definition rather than at view
creation time. (Bug #20515155)
• Built-in SQL functions could raise an assertion or cause a server exit if the wrong thread pointer was
used to produce an error or warning message. (Bug #20454979)
• Incorrect calculation of the length of strings written to the binary log could raise an assertion or cause
a server exit. (Bug #20444737)
References: This issue is a regression of: Bug #16066637.
• The range optimizer interpreted a hidden key part (InnoDB primary key) as a minimum bounding
rectangle (MBR) index. Such primary keys cannot be used as MBRs, and a server exit resulted..
(Bug #20430526)
• The WITH CHECK OPTION of a view was sometimes ignored if the view was included in another
view. For discussion of the implications of this fix, see The View WITH CHECK OPTION Clause.
(Bug #20407961)
• Calculation of “within” or “contains” relationships failed for some types of geometry collections. (Bug
#20379981)
123
MySQL 5.7 Release Notes
• Long path name values for some options could lead to stack overflow. (Bug #20376760)
• Setting the password for an account not using a built-in authentication plugin could cause the
account to become unusable.
The fix for this problem involves a change to the authentication plugin API to add a new
authentication_flags member to the server-side plugin descriptor. See Writing the Server-Side
Authentication Plugin (Bug #20364862)
• Spatial WKT export functions produced too-long string representations of coordinate values instead
of switching to exponential notation. (Bug #20363531)
• An off-by-one error in string-copying code could result in a buffer overflow. (Bug #20359808)
• The events_waits_summary_by_instance Performance Schema table could fail to return rows
for socket instruments. (Bug #20348824)
• Under certain conditions, the libedit command-line library could write outside an array boundary
and cause a client program crash. (Bug #20318154)
• Invalid linestring values with a single point and unclosed polygons with fewer than four points could
cause a server exit. Such invalid values now are rejected. (Bug #20316779)
• mysql_config_editor could exit abnormally while encrypting passwords. (Bug #20294225)
• A corrupt mylogin.cnf file could cause client programs to exit abnormally. (Bug #20294148)
• A deadlock error reported by InnoDB could cause rollback inside InnoDB while the transaction
continued at the SQL layer. (Bug #20262654)
• MySQL sometimes produced no warning when it was unable to interpret a character in a given
character set. (Bug #20238729)
• Host value matching for the grant tables could fail to use the most specific of values that contained
wildcard characters. (Bug #20181776)
• For MySQL distributions linked against yaSSL, a corrupt client key file could cause clients to exit.
(Bug #20168526)
• Use of SELECT COUNT(DISTINCT) in a subquery in the FROM clause could produce incorrect
results. (Bug #20145024)
References: This issue is a regression of: Bug #18766378.
• For join queries with a large number of tables, the server could exit converting the join to a semi-join.
(Bug #20109861)
• ALTER TABLE operations that changed only an index comment were not being treated as a fast/inplace alteration. (Bug #20106553)
• Following execution of a GRANT ... WITH GRANT OPTION statement, execution of a prepared
statement with a view could cause a server exit. (Bug #20030284)
• ADDTIME() could produce an out-of-range result with a year >= 10,000. (Bug #19900900)
• Within a stored procedure, access to view columns after DDL or FLUSH TABLES statements in the
procedure could cause a server exit. (Bug #19897405)
• References to select list columns of the outer query from the HAVING clause of a correlated
subquery in the inner query should, but did not, return an error, resulting in a server exit. (Bug
#19823076)
• Several ST_Envelope() problems were corrected:
124
MySQL 5.7 Release Notes
• If the mimimum bounding rectangle (MBR) of a geometry degrades to a Point or horizontal or
vertical LineString, ST_Envelope() returns that value rather than an invalid polygon.
• The return value for an empty geometry collection now is an empty geometry rather than NULL.
• If a geometry is geometrically invalid but has a valid WKB string, return a valid MBR rather than
NULL.
(Bug #19811953, Bug #20196720)
• For debug builds, an assertion could be raised when a top-level query had a HAVING clause that
contained a subquery referencing a column from the top-level query. (Bug #19811896)
• GROUP BY or ORDER BY on a CHAR(0) NOT NULL column could lead to a server exit. (Bug
#19660891)
• The server could exit if a grouped query had a nongrouped subquery that contained a reference to
an aggregate function. (Bug #19585938)
• Loading corrupt spatial data into a MyISAM table could cause the server to exit during index building.
(Bug #19573096)
• Some spatial functions converted -0 to 0. This no longer occurs. (Bug #19504183)
• For debug builds, certain UPDATE statements could raise an assertion. (Bug #19055268)
• The LooseScan execution strategy for semi-joins failed to evaluate the WHERE condition on rows
coming from the first inner table of an outer join. (Bug #18892055)
• An internal procedure that creates temporary tables and expected a flat list of expressions to map
onto table columns sometimes received a list that was not flat, causing an assertion to be raised.
(Bug #18745214)
• For MyISAM or MEMORY tables, a nested join with a subquery could product a result set with missing
rows when the optimizer_switch condition_fanout_filter flag was enabled. (Bug
#18717059)
• For some status variables that should monotonically increase, SHOW GLOBAL STATUS in one
session could show them as decreasing when other concurrent sessions changed user or
disconnected. (Bug #18591145)
• On Windows, setting query_cache_min_res_unit to too large a value could result in a value of 0
and a subsequent server exit. (Bug #18487951)
• For debug builds, SET statements that assigned a subquery value to a variable could raise an
assertion due to improper cleanup related to GROUP BY or ORDER BY clauses. (Bug #18486509)
• The validate_password plugin was not installed by RPM packages for platorms using systemd or
SysV-style initialization scripts. (Bug #18438833)
• Some queries involving spatial relation checks would produce correct results for MyISAM tables but
not InnoDB tables. (Bug #18422162)
• Deleting rows from an empty MyISAM table with a spatial index resulted in a spurious error message
about a corrupt index. (Bug #18412756)
• Boolean full-text searches for MyISAM tables could fail. (Bug #18279587)
• A client that attempted to establish SSL connections from a large number of threads simultaneously
could exit with a segmentation fault. (Bug #18052165)
• Deletes from CSV tables could cause a server exit. (Bug #17902624)
125
MySQL 5.7 Release Notes
• For HANDLER read statements that scanned a spatial index, type conversion errors of values read
from the index could cause a server exit. (Bug #17846865)
• A query with an IN subquery where the left-hand side was a scalar subquery might cause a server
exit. (Bug #17832047)
• The server could exit under conditions when a query contained the following construct but produced
an empty result:
literal-valued row constructor <=> (subquery containing UNION)
(Bug #17668844)
• If ownership of memory allocation was transferred between threads, Performance Schema memory
instrumentation could report memory use of the threads incorrectly. (Bug #17473077)
• For debug builds, statements including table-less subqueries could raise an assertion when executed
within scheduled events. (Bug #17435114)
• The --help message displayed by mysql_secure_installation did not show options related
to option-file processing, such as --defaults-file. (Bug #17339009)
• Memory usage values in the memory_summary_global_by_event_name Performance Schema
table could be negative. (Bug #17243619)
• For debug builds, an assertion could be raised in character-set conversion code due to an overly
strict condition. (Bug #13740934)
• An event scheduler thread could be freed improperly, potentially leading to a server exit. (Bug
#77593, Bug #21145277, Bug #21053167)
• mysql-systemd-start failed if datadir was set in /etc/my.cnf. (Bug #77357, Bug
#21262883)
• The unused and unmaintained BUILD/build_mccge.sh script has been removed from the source
tree. (Bug #77336, Bug #21246941)
• ST_IsValid() could return false for some valid MultiPolygon arguments. (Bug #77317, Bug
#21238969)
• ST_Buffer() with a LineString argument could produce a Polygon that self-intersected. (Bug
#77316, Bug #21238614)
• Compilation failed when building MySQL without the Performance Schema. (Bug #77292, Bug
#21229433)
• Updating the setup_consumers table to set history or long-history consumers had no affect on
historical event logging for existing threads. (Bug #77278, Bug #21223458)
• SHOW GLOBAL STATUS Com_xxx counters did not reflect SELECT statements. (Bug #77231, Bug
#21186946)
• The outdated and not-maintained plugin/daemon_example/ChangeLog file was removed. (Bug
#77188, Bug #21168681)
• ST_ConvexHull() could return incorrect results for MultiLineString arguments. (Bug #77167,
Bug #21153716)
• Executing a prepared EXPLAIN statement could cause the server to hang. (Bug #77144, Bug
#21139522)
• If the server was started with the --ssl-cipher option, autogeneration and autodetection of SSL
certificates did not work. (Bug #77078, Bug #21108296)
126
MySQL 5.7 Release Notes
• Optimizer hint query block names are identifiers, but the parser did not recognize valid identifer
names such as 123a when used in @query_block_name syntax. (Bug #77047, Bug #21095608)
• For mysqldump, the -T option is supposed to be the short form of the --tab option, but was
mistakenly associated with --debug-info instead. (Bug #77037, Bug #21088793)
References: This issue is a regression of: Bug #66854.
• SSL certificates autogenerated by the server could have CN values that exceeded 64 characters.
In that case, the server now omits the _server_version part of the CN values so the length falls
within 64 characters. (Bug #77036, Bug #21087159)
• The Common Name value written by mysql_ssl_rsa_setup to the client-cert.pem client
certificate file was MySQL_Server_suffix_Auto_Generated_Server_Certificate rather
than MySQL_Server_suffix_Auto_Generated_Client_Certificate. (Bug #77035, Bug
#21087116)
• Deallocation of Debug Sync structures within the InnoDB handlerton close connection method could
raise an assertion. (Bug #77005, Bug #21069721)
• Queries on a geometry column returned an error instead of a result if there existed a UNIQUE index
on the column. (Bug #77000, Bug #21067378)
• An assertion could be raised if a multiple-table UPDATE of a view, where the same column was used
in the SET and JOIN clauses, was used as a prepared statement. (Bug #76962, Bug #21045724)
• With row-based binary logging, automatic dropping of a scheduled event that had reached the end of
its lifetime could raise an assertion. (Bug #76958, Bug #21041908)
• If a single-table subquery had identical GROUP BY and ORDER BY clauses on a UNIQUE NOT NULL
column, the results could be incorrectly ordered. (Bug #76947, Bug #21038929)
• The PARSE_GCOL_EXPR keyword used internally by the parser was treated as a reserved word and
thus could not be used as an identifier without quoting it. (Bug #76943, Bug #21035515)
• When the directory specified for the secure_file_priv system variable did not exist, the server
produced a Failed to normalize the argument error message. It now produces a message
indicating that the directory did not exist. The same problem occurred for the --datadir option to
mysql_ssl_rsa_setup and was fixed the same way. (Bug #76918, Bug #21021894)
• For logging to the binary log, the server could rewrite CREATE USER and ALTER USER statements,
adding an ACCOUNT UNLOCK clause not present in the original statement. This could unlock locked
accounts and cause differences between master and slave servers. The clause is no longer written
unless present in the original statement. (Bug #76911, Bug #20996273)
• The INDEX_NAME column of the Performance Schema
table_io_waits_summary_by_index_usage table could sometimes show incorrect index
names for tables until they had been in use for some time. (Bug #76882, Bug #20980217)
• Compilation could fail in the query rewrite plugin code for some CMake options. (Bug #76800, Bug
#20937654)
• DO statements containing multiple expressions could result in a memory leak.
A consequence of the bug fix is that DO statement errors previously converted to warnings now are
returned as errors. (Bug #76779, Bug #20924241, Bug #17479887)
• Previously, SSL files created automatically by the server were valid for one year. The validity period
has been extended to ten years (the same as SSL files created by mysql_ssl_rsa_setup). (Bug
#76778, Bug #20923066)
• mysql_upgrade failed if the show_compatibility_56 system variable was enabled. (Bug
#76757, Bug #20914786)
127
MySQL 5.7 Release Notes
• Unaligned memory access could cause spatial operations to fail. (Bug #76748, Bug #20911624)
• Identifiers in normalized statements were sometimes quoted and sometimes not, an inconsistency
that caused matching failure for statement digests and digest texts. This caused problems for
Performance Schema aggregation by digest. Identifiers now are quoted consistently. (Bug #76723,
Bug #20896539)
• Ubuntu packages were missing dependencies for killall and psmisc. (Bug #76716, Bug
#20893836)
• SHOW GLOBAL VARIABLES and selecting from the INFORMATION_SCHEMA GLOBAL_VARIABLES
table resulted in a spurious warning about the sql_log_bin system variable. (Bug #76626, Bug
#20854952)
• mysqld --help --verbose was slow if the InnoDB buffer pool was configured to a large size.
Now with those options, buffer pool allocation is not performed. (Bug #76625, Bug #20856397)
• An assertion could be raised for queries with a GROUP BY clause and a table for which the optimizer
identified multiple candidate indexes. (Bug #76576, Bug #20819199)
• CREATE USER events written to the binary log included the new ACCOUNT syntax even with
log_backward_compatible_user_definitions enabled. (Bug #76560, Bug #20814051)
• The server rejected empty COM_SHUTDOWN packets. (Bug #76552, Bug #20810928)
References: This issue is a regression of: Bug #14525642.
• For some startup errors, the server could call exit() before shutting down plugins and thus failed to
invoke their atexit() handlers. (Bug #76532, Bug #20798617)
• In sql/handler.h, HA_ATTACHABLE_TRX_COMPATIABLE and HA_GENERATED_COLUMNS were
defined with the same value. (Bug #76503, Bug #20783191)
• mysqlimport --use-threads did not actually use multiple threads. (Bug #76480, Bug
#20772273)
• The mutex used for the optimizer cost model cost-constant cache was not instrumented by
the Performance Schema. This instrument is now available as wait/synch/mutex/sql/
Cost_constant_cache::LOCK_cost_const. (Bug #76460, Bug #20755430)
• These statement-timeout problems were corrected:
• An assertion could be raised with max_statement_time set greater than zero and multiple
concurrent sessions executing certain EXPLAIN statements.
• The error message indicating that statement execution was interrupted referred to the
max_statement_time system variable, even if the relevant timeout was a per-statement value.
The error message is now more generic.
• It was not possible to set the max_statement_time system variable at server startup.
• Setting max_statement_time to set a statement timeout could cause memory leaks or assertion
failures on Windows.
• Attempting to kill statements that use attachable transactions caused subsequent statements to
function improperly, resulting in assertion failures. A max_statement_time timeout on such
statements could produce a similar outcome.
Note
Subsequent to these changes, the max_statement_time system variable
was renamed to max_execution_time.
128
MySQL 5.7 Release Notes
(Bug #76446, Bug #20788811, Bug #76915, Bug #21021670, Bug #76916, Bug #21021754, Bug
#20705648, Bug #20705642, Bug #75782, Bug #20507804)
References: See also: Bug #77461, Bug #21306646.
• Attempts to create a foreign key matching a FULLTEXT index failed. For debug builds, attempts to
create a foreign key matching a SPATIAL index raised an assertion. (Bug #76445, Bug #20752436)
• The ORDER BY clause of a derived table was appended to an INSERT statement, but ordering for a
table being inserted into is irrelevant and caused a server exit. (Bug #76436, Bug #20753569)
• A failing ALTER TABLE tablespace operation (DISCARD TABLESPACE or IMPORT TABLESPACE
could produce an incorrect internal tablespace state, causing a succeeding statement to fail. (Bug
#76424, Bug #20748660)
• Enabling the sql_buffer_result system variable could cause a server exit for multiple-table
UPDATE statements. (Bug #76419, Bug #20748537)
• The value of secure_file_priv displayed as NULL for both --secure_file_priv=NULL
(correct) and --secure_file_priv="" (incorrect). (Bug #76401, Bug #20741572)
• A Provides rule in RPM .spec files misspelled “mysql-embedded” as “mysql-emdedded”. (Bug
#76385, Bug #20734434)
• Compiling using Clang 3.5 or higher with AddressSanitizer (ASAN) enabled caused the
gen_lex_hash utility to abort on Clang LeakSanitizer memory leak check failures. (Bug #76351,
Bug #20720615, Bug #22558597, Bug #80014)
• SHOW CREATE TABLE did not correctly display generated columns that had a character set defined.
(Bug #76328, Bug #20709462)
• The Com_stmt_reprepare status variable was missing from the global_status and
session_status Performance Schema tables. (Bug #76305, Bug #20697446)
• Attempts to establish SSL connections to a Community Edition server failed if the client had a
password and the server did not have the general query log enabled. (Bug #76286, Bug #20693153)
• Prepared statement execution statistics were not correctly tracked in the
prepared_statements_instances Performance Schema table. (Bug #76284, Bug #20692556)
• Some server warnings referred to the now-deprecated mysql_install_db command. (Bug
#76251, Bug #20681412)
• Compilation could fail due to a missing dependency on lex_token.h for sql_yacc.cc.o. (Bug
#76235, Bug #20678411)
• EXPLAIN for a query containing an uncorrelated subquery could attempt to materialize the subquery
twice, raising an assertion. (Bug #76205, Bug #20665051)
• Debian and Ubuntu package installers neglected to run mysql_ssl_rsa_setup during installation.
(Bug #76163, Bug #20650118)
• Global status variables related to SSL certificate metadata were available only within sessions
established using SSL. (Bug #76157, Bug #20648276)
• The mysql_real_escape_string_quote() C API function failed to escape backtick (`)
characters when the NO_BACKSLASH_ESCAPES SQL mode was disabled. (Bug #76146, Bug
#20645725)
• The message displayed to indicate that a password was expired and must be reset referred to
the deprecated SET PASSWORD statement. It now refers to ALTER USER. (Bug #76053, Bug
#20602572)
129
MySQL 5.7 Release Notes
• ALTER USER statements that named an authentication plugin did not check whether the plugin is
valid. (Bug #76052, Bug #20602525)
• If a proxy user expired the password of the proxied user, the current proxy user session was affected
(the server considered its password expired). To execute SQL statements again, it was necessary
for the proxy user to disconnect and reconnect again. (Bug #76043, Bug #20599280)
• mysqld --help --verbose tried to perform actions that have nothing to do with displaying a help
message: Locking files, initializing system files, and checking for a plugin table. (Bug #75995, Bug
#20581228)
• For a SET = (subquery) statement within a stored procedure, the server could exit if a subquery
transformation was performed. (Bug #75994, Bug #20583321)
• Code for reading and writing the grant tables assumed that these were MyISAM tables and did
not handle errors that can be thrown if the tables are handled by a different storage engine. (Bug
#75955, Bug #20561087)
• Several spatial function issues were resolved by use of Boost.Geometry for GIS algorithms:
• ST_Centroid() with a MultiPolygon argument could produce incorrect results.
• Multiple calls to ST_Intersection() could return inconsistent results for some arguments.
• ST_Within() and ST_Touches() could return incorrect results for some arguments.
(Bug #75829, Bug #20508769, Bug #69425, Bug #19270344, Bug #69538, Bug #19270334)
• Nonoptimal cost estimates for key lookups could cause some queries to be executed with a table
scan rather than key lookups. (Bug #75695, Bug #20443863)
• Operations on a string exceeding max_allowed_packet bytes could return NULL and incorrectly
replace an existing value in UPDATE statements with NULL rather than failing. (Bug #75539, Bug
#20376498)
• The MeCab full-text parser plugin was omitted from RPM and Debian packages. (Bug #75429, Bug
#20315007)
• EXPLAIN for INSERT ... SELECT statements into a multiple-table view always displayed the first
table of the view as the table being inserted into, even if it was not. (Bug #75424, Bug #20310257)
• The parser could dereference a null pointer after an out-of-memory error. (Bug #75372, Bug
#20294206)
• Some queries could return different results depending on whether the semijoin flag of the
optimizer_switch system variable was enabled or disabled. (Bug #75270, Bug #20239912)
• With a small thread stack, queries with many expressions could produce a thread stack overrun
error. (Bug #74985, Bug #20087571)
• On platforms where the char is unsigned, the server was unable to parse collation definitions that
included non-7-bit ASCII characters. Affected platforms include ARM and PowerPC. Thanks to
Alexey Kopytov for the patch. (Bug #74891, Bug #20928289, Bug #21682439)
• If the server was started with the explicit_defaults_for_timestamp system variable enabled,
CREATE TABLE statements that defined a column as TIMESTAMP NOT NULL failed. (Bug #74529,
Bug #19881933)
• In the threads Performance Schema table, the PROCESSLIST_STATE and PROCESSLIST_INFO
values did not change for the thread/sql/main main thread instrument as the thread state
changed. (Bug #74517, Bug #19887143)
130
MySQL 5.7 Release Notes
• On OS X 10.10 (Yosemite), mysqld failed to start automatically. The startup item has been replaced
with a launchd job, which enables the preference pane checkbox for automatic startup to work
again. (Bug #74434, Bug #19858350)
• Specifying a bad --init-file option value could cause the server to hang at startup. (Bug
#74402, Bug #19822257)
• mysql_install_db did not write a date to the .mysql_secret file. (Bug #74006, Bug
#19659004)
• Incorrect results could be produced tor views and derived tables on the inner side of an outer
join and from which non-nullable expressions such as literals were selected. (Bug #73953, Bug
#20841369, Bug #67014, Bug #15967464, Bug #65936, Bug #14358878, Bug #67300, Bug
#15936817, Bug #76327, Bug #20708288)
• If a spatial column contained invalid spatial data, creating a SPATIAL index on the column failed to
produce an error. (Bug #73871, Bug #19593342)
• Certain queries for the INFORMATION_SCHEMA TABLES and COLUMNS tables could lead to
excessive memory use when there were large numbers of empty InnoDB tables. (Bug #72322, Bug
#18592390)
• Large integer literals converted to floats for comparison with decimal data could lose precision and
produce incorrect results. (Bug #72056, Bug #18411494, Bug #21139707)
• When choosing join order, the optimizer could incorrectly calculate the cost of a table scan and
choose a table scan over a more efficient eq_ref join. (Bug #71584, Bug #18194196)
• The server interpreted --tc-heuristic-recover option values incorrectly due to an off-by-one
error. Thanks to Laurynas Biveinis for the patch. (Bug #70860, Bug #19771769)
• On OS X, the vio_io_wait() call could cause stack corruption for a large number of file
descriptors (more than FD_SETSIZE). (Bug #69903, Bug #17259750)
• Queries that included a HAVING clause based on nondeterministic functions could produce incorrect
results. (Bug #69638, Bug #17055185)
• MySQL failed to compile using OpenSSL 0.9.8e. (Bug #68999, Bug #16861371)
• For mysqlslap, the combination of --auto-generate-sql-secondary-indexes and -auto-generate-sql failed because it tried to insert 36-digit UUID values into a VARCHAR(32)
column. Thanks to Tsubasa Tanaka for the patch. (Bug #55265, Bug #11762644)
Changes in MySQL 5.7.7 (2015-04-08, Release Candidate)
• Compilation Notes
• Installation Notes
• Optimizer Notes
• Packaging Notes
• Performance Schema Notes
• Security Notes
• Spatial Data Support
• sys Schema Notes
• Functionality Added or Changed
131
MySQL 5.7 Release Notes
• Bugs Fixed
Compilation Notes
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Installation Notes
• Installers for more binary distribution types provide secure deployment. This includes installers for
SLES, Solaris, OS X, FreeBSD, and Linux generic binary compressed tar distributions. These
installers create a single 'root'@'localhost' account without other root or anonymoususer accounts, and do not create a test database accessible by any user. (Some installers may
provide options to create additional accounts or a test database, but only if selected by the user.)
Installers that run interactively and can ask the installing user for the initial root password do
so. Noninteractive installers generate a random root password that the administrator can use to
connect to the server the first time and choose a new password.
Optimizer Notes
• It is now possible to provide hints to the optimizer within individual SQL statements, which enables
finer control over statement execution plans than can be achieved using the optimizer_switch
system variable. Optimizer hints are specified as /*+ ... */ comments following the SELECT,
INSERT, REPLACE, UPDATE, or DELETE keyword of statements or query blocks. Hints are also
permitted in statements used with EXPLAIN, enabling you to see how hints affect execution plans.
Examples:
SELECT /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY, f2_idx) */ f1
FROM t3 WHERE f1 > 30 AND f1 < 33;
SELECT /*+ BKA(t1) NO_BKA(t2) */ * FROM t1 INNER JOIN t2 WHERE ...;
SELECT /*+ NO_ICP(t1, t2) */ * FROM t1 INNER JOIN t2 WHERE ...;
EXPLAIN SELECT /*+ NO_ICP(t1) */ * FROM t1 WHERE ...;
For more information, see Optimizer Hints.
Packaging Notes
• Several binary distribution types have been made more modular, to split out test components into a
separate distribution file. This reduces the size of the main download. In addition to the previously
available test/debug distributions already available for Windows Zip archives, RPM packages, and
Debian packages, the current release makes separate test distributions available for Solaris PKG
files, and generic binary Linux and OS X compressed tar packages. These separate distributions
have “test” in the distribution file name.
Generally, use of a test distribution requires that the main distribution is also installed. Additionally,
for Solaris, the main and test distributions must be for the same version of MySQL.
References: See also: Bug #20613327, Bug #20546298.
Performance Schema Notes
• The events_statements_history and events_transactions_history consumers now are
enabled by default.
References: See also: Bug #71207, Bug #18376132.
Security Notes
• Previously, proxy user mapping was available only for authentication plugins that implemented that
capability for themselves. The MySQL server itself now can map proxy users according to granted
132
MySQL 5.7 Release Notes
proxy privileges. If the new check_proxy_users system variable is enabled, the server performs
proxy user mapping for any authentication plugin that requests it. By default, check_proxy_users
is disabled, so the server performs no proxy user mapping even for authentication plugins that
request it.
In addition, the mysql_native_password and sha256_password built-in authentication
plugins have been modified to take advantage of this server capability, and thus now are
able to support proxy users. The new mysql_native_password_proxy_users and
sha256_password_proxy_users system variables control whether each plugin requests proxy
user mapping. By default, both variables are disabled, which produces behavior that is backward
compatible with previous releases.
For information about user proxying, see Proxy Users.
• The C client library now attempts to establish an encrypted connection by default if the server
supports encrypted connections. This affects client programs as follows:
• In the absence of an --ssl option, clients attempt to connect using encryption, falling back to an
unencrypted connection if an encrypted connection cannot be established.
• The presence of an explicit --ssl option or a synonym (--ssl=1, --enable-ssl) is
prescriptive: Clients require an encrypted connection and fail if one cannot be established.
• With an --ssl=0 option or a synonym (--skip-ssl, --disable-ssl), clients use an
unencrypted connection.
For more information, see Command Options for Encrypted Connections.
This change affects these standard MySQL client programs: mysql, mysql_config_editor,
mysql_install_db, mysql_plugin, mysql_secure_installation, mysql_upgrade,
mysqladmin, mysqlbinlog, mysqlcheck, mysqldump, mysqlimport, mysqlshow, and
mysqlslap. It will also affect new releases of MySQL Connectors that are based on the C client
library: Connector/C, Connector/C++, and Connector/ODBC.
Spatial Data Support
• The ST_Buffer(), ST_Difference(), ST_Distance(), ST_Intersection(),
ST_IsSimple(), ST_SymDifference(), and ST_Union() functions have been reimplemented
to use the functionality available in Boost.Geometry. The functions may raise an exception for invalid
geometry argument values when the previous implementation may not have.
In addition, ST_Buffer() now takes up to three optional arguments to specify point, join, and end
strategies that influence buffer computation. Values for strategy arguments are produced using the
new ST_Buffer_Strategy() function. See Spatial Operator Functions.
sys Schema Notes
• MySQL distributions now include the sys schema, a set of objects that helps DBAs and developers
interpret data collected by the Performance Schema. sys schema objects can be used for typical
tuning and diagnosis use cases.
For new installations, the sys schema is installed by default during data directory initialization if
you use mysqld with the --initialize or --initialize-insecure option, or if you use
mysql_install_db. To permit this behavior to be suppressed, mysql_install_db now has a
--skip-sys-schema option. mysqld has no such option, but if you initialize the data directory
using mysqld --initialize (or --initialize-insecure) rather than mysql_install_db,
you can drop the sys schema manually after initialization if it is unneeded.
For upgrades, mysql_upgrade installs the sys schema if it is not installed, and upgrades it to the
current version otherwise. To permit this behavior to be suppressed, mysql_upgrade now has a -skip-sys-schema option.
133
MySQL 5.7 Release Notes
mysql_upgrade returns an error if a sys schema exists but has no version view, on the
assumption that absence of this view indicates a user-created sys schema. To upgrade in this case,
remove or rename the existing sys schema first.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade to
install the sys schema.
For more information, see MySQL sys Schema.
Functionality Added or Changed
• Important Change; InnoDB: The following changes were made to InnoDB configuration parameter
default values:
• The innodb_file_format default value was changed to Barracuda. The previous default
value was Antelope. This change allows tables to use Compressed or Dynamic row formats.
• The innodb_large_prefix default value was changed to ON. The previous default was OFF.
When innodb_file_format is set to Barracuda, innodb_large_prefix=ON allows
index key prefixes longer than 767 bytes (up to 3072 bytes) for tables that use a Compressed or
Dynamic row format.
• The innodb_strict_mode default value was changed to ON. The previous default was OFF.
When innodb_strict_mode is enabled, InnoDB raises error conditions in certain cases,
rather than issuing a warning and processing the specified statement (perhaps with unintended
behavior).
The configuration parameter default changes described above may affect replication and
mysqldump operations. Consider the following recommendations when using the new default
settings:
• When replicating or replaying mysqldump data from older MySQL versions to MySQL 5.7.7 or
higher, consider setting innodb_strict_mode to OFF to avoid errors. Target settings should not
be more strict than source settings.
• When replicating from MySQL 5.7.7 or higher to older slaves, consider setting
innodb_file_format=Barracuda and innodb_large_prefix=ON on the slave so that the
target and source have the same settings.
The following file format related configuration parameters are deprecated and will be removed in a
future release:
• innodb_file_format
• innodb_file_format_check
• innodb_file_format_max
• innodb_large_prefix
These four configuration parameters were provided for creating tables compatible with earlier
versions of InnoDB in MySQL 5.1. Now that MySQL 5.1 has reached the end of its product lifecycle,
the parameters are no longer required. Also, the file format scheme, by which named file formats
would be introduced as new features were added, was not used after introduction of the Barracuda
file format. InnoDB formats have changed since the introduction of the Barracuda file format, but
new named file formats have not been added.
If non-default values are used for any of the four deprecated parameters, InnoDB prints a
deprecation and removal warning to the server error log. The same warning is issued to the client if
the parameters are set dynamically using a SET statement.
134
MySQL 5.7 Release Notes
• Important Change; InnoDB: The innodb_buffer_pool_dump_at_shutdown and
innodb_buffer_pool_load_at_startup configuration options are now enabled by
default. With this change, a percentage of most-recently-used buffer pool pages is dumped at
server shutdown and restored at server startup. This behavior helps avoid a lengthy buffer pool
warmup period after restarting the server, particularly for instances with large buffer pools. The
innodb_buffer_pool_dump_pct option defines the percentage of buffer pool pages that are
dumped. The default value for innodb_buffer_pool_dump_pct is reduced from 100 to 25.
These configuration option default value changes represent a change in behaviour at server
shutdown and startup. If you prefer the previous default values, it is recommended that you configure
the options explicitly in your MySQL configuration file after upgrading to MySQL 5.7.7 or later, and
before restarting the server.
For more information, see Saving and Restoring the Buffer Pool State.
• Important Change; InnoDB: The innodb_checksum_algorithm default value is
now crc32. The previous default setting was innodb. This change also means that
innodb_checksums=ON is now equivalent to innodb_checksum_algorithm=crc32 instead of
innodb_checksum_algorithm=innodb.
• InnoDB: The InnoDB MeCab full-text parser plugin now supports the eucjpms, cp932, and
utf8mb4 character sets. (Bug #20534096)
• InnoDB: To address a scalability bottleneck for some workloads where LOCK_grant is locked
in read-mode, LOCK_grant locks are now partitioned. Read lock requests on LOCK_grant now
acquire one of multiple LOCK_grant partitions. Write locks must acquire all partitions.
To address another scalability bottleneck, the server no longer performs unnecessary lock
acquisitions when creating interal temporary tables.
References: See also: Bug #72829, Bug #20023139.
• Replication: The defaults of some replication related variables have been modified. The following
changes have been made:
• binlog_gtid_simple_recovery=TRUE
• binlog-format=ROW
• binlog_error_action=ABORT_SERVER
• sync_binlog=1
• slave_net_timeout=60
Additionally, the session scope of gtid_executed has been deprecated. The global scope of
gtid_executed remains supported.
• Replication: The XA implementation in MySQL has been made much more compatible with the XA
specification. A prepared XA transaction is no longer rolled back at disconnect. Now when replicating
using the binary log, an XA transaction in PREPARED state persists in the binary log until an explicit
XA COMMIT or XA ROLLBACK statement is issued. In prior versions, an XA transaction that was in
PREPARED state would be rolled back on clean server shutdown or client disconnect. Similarly, an
XA transaction that was in PREPARED state would still exist in PREPARED state in case the server
was shut down abnormally and then started again, but the contents of the transaction could not
be written to the binary log. As part of this feature, a new event, XA_prepare_log_event, has
been added to track XA transactions in the PREPARED state and enable them to be replicated. To
finalize a two-phase XA transaction, the XA COMMIT or XA ROLLBACK is recorded separately in the
binary log, possibly interleaving with other transactions. XA transactions committed with the new XA
COMMIT ONE PHASE syntax are logged as one part using XA_prepare_log_event.
135
MySQL 5.7 Release Notes
References: See also: Bug #12161, Bug #11745231, Bug #75204, Bug #20214365.
• Performance Schema stage event instruments that provide statement progress information now are
enabled and timed by default. The affected instruments are those displayed by this statement:
SELECT * FROM performance_schema.setup_instruments WHERE
ENABLED='YES' AND NAME LIKE "stage/%";
(Bug #20685859)
• The XID column of Performance Schema transaction tables (for example,
events_transactions_current) has been split into three columns to permit access to
the component parts of XID values. The new columns are XID_FORMAT_ID, XID_GTRID, and
XID_BQUAL. (Bug #18320361)
• In MySQL 5.7.6, the NO_AUTO_CREATE_USER was deprecated. (It is preferable to create
MySQL accounts with CREATE USER rather than GRANT.) Now the default SQL mode includes
NO_AUTO_CREATE_USER and assignments to sql_mode that change the NO_AUTO_CREATE_USER
mode state produce a warning, except assignments that set sql_mode to DEFAULT.
NO_AUTO_CREATE_USER will be removed in a future MySQL release, at which point its effect will be
enabled at all times (GRANT will not create accounts).
• Previously, view definitions were not permitted to contain derived tables (subqueries) in the FROM
clause. This restriction has now been lifted.
Previously, derived tables (subqueries) or views in the FROM clause could not be merged into the
outer query if they contained subqueries in the SELECT list. Instead, they were processed using
materialization. This restriction has now been lifted so that queries previously executed using
materialization can be executed more quickly using merging. (Bug #12755, Bug #11745276, Bug
#60417, Bug #11865600)
Bugs Fixed
• InnoDB: FLUSH TABLES ... FOR EXPORT, which is an unsupported operation for tables residing
in a general tablespace, failed to report a warning message. (Bug #20631305)
• InnoDB: The MeCab parser accessed the byte beyond the length of the document resulting in an
Invalid read of size 1 Valgrind error. Document allocation size is now length + 1 byte. (Bug
#20589432)
• InnoDB: A debug assertion should not be raised for static mutexes. (Bug #20588765)
• InnoDB: Tablespace and file path data updates to internal system tables during startup caused undo
log corruption. The updates were made before calling truncate::fixup_tables(), which does
not expect to encounter changed pages. (Bug #20534616)
• InnoDB: A TRUNCATE TABLE operation on a temporary table raised an assertion. The temporary
table object was incompletely constructed when reloaded from SYS_TABLES. (Bug #20527363, Bug
#72080)
• InnoDB: Return value 16 when calling pthread_mutex_destroy() warnings were
returned during atexit() processing. (Bug #20513522)
• InnoDB: A debug variable used to modify the first page of a tablespace raised an assertion when set
to a nonexistent tablespace ID. (Bug #20511314, Bug #75833, Bug #19865274, Bug #74481)
• InnoDB: A buffer pool load operation raised an assertion when attempting to read pages that were
placed out of tablespace bounds by a preceding TRUNCATE TABLE operation. (Bug #20474542)
• InnoDB: Removal of a foreign key object from the data dictionary cache during error handling
caused the server to exit. (Bug #20442523)
136
MySQL 5.7 Release Notes
• InnoDB: An assertion was raised during a redo log resize operation that was triggered by a file size
mismatch encountered during recovery. Code introduced in MySQL 5.6.8 to automatically handle
redo log file size mismatches failed to ensure that the buffer pool was clean prior to recreating redo
log files. (Bug #20425387)
• InnoDB: An InnoDB memcached extra_col_value[] array was freed without checking the
allocated flag, causing a server exit. (Bug #20400373)
• InnoDB: A DML operation performed while a flushing operation was in progress raised a
memcached-related assertion. (Bug #20390277)
• InnoDB: A CHECK TABLE operation on a table with a spatial index raised an assertion. The
row_sel_sec_rec_is_for_clust_rec function failed to handle an externally stored field. (Bug
#20311344)
• InnoDB: CHECK TABLE reported misplaced rows after an in-place ALTER TABLE operation on a
“partitioned by key” table. An in-place operation that drops and adds the primary key should not be
permitted for tables that are partitioned by key. (Bug #20190520)
• InnoDB: Estimates that were too low for the size of merge chunks in the result sorting algorithm
caused a server exit. (Bug #20049521)
• InnoDB: An ALTER TABLE ... RENAME operation raised an invalid assertion. The assertion code
used an incorrect transaction object. (Bug #18523599)
References: This issue is a regression of: Bug #17447500.
• InnoDB: Running mysql_upgrade after a binary upgrade to MySQL 5.7.6 caused a server exit
on a system with tablespace data files that were created in MySQL 5.1 or earlier. The fix for Bug
#17345513 in MySQL 5.7.6 failed to address all instances of garbage FIL_PAGE_TYPE values in
tablespace data files created in MySQL 5.1 or earlier.
With this patch, the manual process described in the MySQL 5.7.6 release notes entry for Bug
#17345513 for repairing non-index pages that contain invalid FIL_PAGE_TYPE values is no longer
necessary.
The patch for Bug #17345513 also failed to recompute page checksums after resetting invalid
FIL_PAGE_TYPE values. Upon restarting the server, a failure would occur due to an apparent page
corruption. The page checksum is now recomputed before the new FIL_PAGE_TYPE value is written
to the data file. (Bug #76262, Bug #20691930)
References: This issue is a regression of: Bug #17345513.
• InnoDB: For full-text searches, the optimizer could choose an index that does not produce correct
relevancy rankings. (Bug #74686, Bug #19950568)
• Partitioning: The MySQL Server unnecessarily requested the default number of partitions for a
table whenever it opened a partitioned table. This was unnecessary since the server already has
this information about the table to be opened. Now the server requests this information only when
needed—that is, only if it is creating or altering a partitioned table. (Bug #76007, Bug #20585753)
• Partitioning: A number of ALTER TABLE statements that attempted to add partitions, columns, or
indexes to a partitioned table while a write lock was in effect for this table were not handled correctly.
(Bug #74451, Bug #74478, Bug #74491, Bug #74560, Bug #74746, Bug #74841, Bug #74860, Bug
#74869, Bug #19856162, Bug #19864284, Bug #19873019, Bug #19891663, Bug #19990815, Bug
#20026661, Bug #20031966, Bug #20033503, Bug #19827845)
• Partitioning: Executing an ALTER TABLE on a partitioned table on which a write lock was in effect
could cause subsequent SQL statements on this table to fail. (Bug #74288, Bug #74634, Bug
#19784790, Bug #19918805)
References: See also: Bug #19856162, Bug #74451.
137
MySQL 5.7 Release Notes
• Replication: Some memory copy operations being performed on the
replication_connection_status Performance Schema table were using an incorrect length,
which could lead to a buffer overflow error or truncated output. The fix ensures that the correct length
is used. (Bug #20535692)
• Replication: When using multi-source replication on a multi-threaded slave (where
slave_parallel_workers is greater than 1), and slave_transaction_retries was greater
than 1, the slave would fail to open the relay log file. This was due to the slave worker incorrectly
constructing the relay log file path for its replication channel. (Bug #20448413)
• Replication: When the automatic_sp_privileges variable is set, the server automatically
grants the EXECUTE and ALTER ROUTINE privileges to the creator of a stored routine, if the user
does not already have these privileges. When a privileged user creates a procedure with DEFINER
as a non privileged user on a master, the current user is considered to be a privileged user and the
mysql.procs_priv table is not updated. When such a statement was replicated to slave, the
non-privileged DEFINER was considered as the current user on the slave and privileges were being
allocated. This caused a difference in the privileges that were being allocated on the master and
the slave. The fix ensures that creater of the stored routine is added to the binary log, and the slave
now checks first if the user exists before granting privileges. To maintain compatibility with previous
versions, the DEFINER is used when the INVOKER is not available. As part of this fix, anonymous
users can be used to replicate from master to slave. (Bug #20049894)
• Replication: If the I/O thread on a replication slave failed while it was in the initialization phase,
it was not providing this information in the Last_IO_Error field after issuing SHOW SLAVE
STATUS. The fix ensures that such errors are reported correctly in the Last_IO_Error field. (Bug
#18909984)
• Replication: After issuing RESET SLAVE, the RECEIVED_TRANSACTION_SET field in the
performance_schema.replication_connection_status table showed incorrect values.
This could cause an incorrect string value error. (Bug #18751585, Bug #19840342)
• Replication: When gtid_mode=ON and slave_net_timeout was set to a low value, the slave I/
O thread could appear to hang. This was due to the slave heartbeat not being sent regularly enough
when the dump thread found many events that could be skipped. The fix ensures that the heartbeat
is sent correctly in such a situation. (Bug #74607, Bug #19975697)
• CMake failed to detect the OpenSSL version properly for recent versions of OpenSSL (the format of
the version string changed). (Bug #20756770)
• GRANT and ALTER USER could clear the password-expiration flag for operations not related to
resetting the password. (Bug #20634154)
• For upgrades from MySQL 5.6 to 5.7 that involve moving mysql.user table passwords from the
Password column to the authentication_string column, mysql_upgrade neglected to
handle rows with an empty plugin value and a pre-4.1 password hash. (Bug #20614545)
• For table-modifying statements, the parser could dereference the parse tree without checking for outof-memory conditions or null pointers. (Bug #20607407)
• mysql_stmt_prepare() could leak memory allocated to metadata. (Bug #20598261)
• Debian packages were missing some dependencies. (Bug #20561621)
• A server exit could be caused by a query that contained a HAVING clause, which itself contained an
IN() subquery predicate, where the subquery referenced a column of the query. (Bug #20558891)
• In MySQL 5.7.6, the PASSWORD() function was deprecated, but no warning was produced when it
was invoked. Similarly, the old_passwords system variable was deprecated, but no warning was
produced when it was set. (Bug #20545464)
• The server could exit if a client using the cleartext authentication plugin attempted to connect with an
empty password. (Bug #20537246)
138
MySQL 5.7 Release Notes
• A query cache invalidation function used a too-small buffer for holding encoded database names,
which could result in a server exit. (Bug #20528928)
• Valgrind warnings were silenced for display of GTID-related debug information. (Bug #20506672)
• Some queries that had a derived table (subquery) in the FROM clause could raise an assertion. (Bug
#20487336)
• A table-modifying statement that followed a failed table-modifying could result in a server exit. (Bug
#20460208)
• Union queries over views containing ENUM or SET values were not handled properly. (Bug
#20456178)
• A natural left join between between a derived table and a regular table, joined with another natural
left join to another regular table could cause a server exit. (Bug #20455184)
• The optimizer could try to create an index of the wrong data type on internal temporary tables. (Bug
#20454833)
• A multiple-table UPDATE statement where one of the specified tables was a derived table could
cause a server exit. (Bug #20454533)
• Mishandling of SRID values within ST_GeomFromGeoJSON() could cause an assertion to be raised.
(Bug #20416705)
• Under certain conditions, LCASE(), DECODE(), and ENCODE() could have source and destination
overlap in memory-copying operations. (Bug #20315088, Bug #75931, Bug #20554017)
• ST_Distance() could return incorrect results on 32-bit platforms. (Bug #20259578)
• If a view was processed using the MERGE algorithm and had an ORDER BY clause, an error
occurred if the view was queried using GROUP BY with the ONLY_FULL_GROUP_BY SQL mode
enabled, unless the query selected all view columns. (Bug #20210742)
• For debug builds, the optimizer could reject use of LooseScan for eq_ref access joins and raise an
assertion. The optimizer now permits this combination for query execution. (Bug #20119743)
• An out-of-range error in a subquery could raise an assertion. (Bug #20035071)
• Renaming the mysql.procs_priv table and executing SHOW GRANTS resulted in a server exit.
(Bug #20006361)
• Ordering by a GROUP_CONCAT() result could cause a server exit. (Bug #19880368, Bug #20730220)
• The server could exit due to an inappropriate full-text lookup using a full-text predicate within a
subquery that contained an outer reference. (Bug #19828320)
• For a prepared statement with an ORDER BY that refers by column number to a GROUP_CONCAT()
expression that has an outer reference, repeated statement execution could cause a server exit.
(Bug #19814337)
• For a materialized internal temporary table used with semi-joins, the optimizer could add an index
to it but then use an inappropriate lookup strategy, causing a server exit. (Bug #19695490, Bug
#21782943)
• The optimizer could raise an assertion due to incorrectly associating an incorrect field with a
temporary table. (Bug #19612819, Bug #20730129)
• Specifying --general_log_file= (with an empty value) at server startup caused the server to fail
and exit. (Bug #19392264)
• Improper propagation of ORDER BY for a derived table or view used within a multiple-table UPDATE
could raise an assertion. (Bug #18439019)
139
MySQL 5.7 Release Notes
• The thd_proc_info() function defined in plugin.h was not actually implemented. This has been
changed to set_thd_proc_info(). (Bug #11844974)
• For debug builds, an assertion was raised when calculating the symmetric difference between a
MultiLineString and a MultiPoint. (Bug #77580, Bug #21355906)
• The query rewrite framework introduced in MySQL 5.7.6 produced excesssive mutex acquisition that
caused performance degradation under some conditions. (Bug #76509, Bug #20785598)
• mysql_install_db started mysqld in bootstrap mode, but failed to wait for it to finish, causing
premature shutdown and the need for crash recovery. (Bug #76344, Bug #20728488)
• SHOW CREATE USER did not work for clients older than MySQL 5.7. (Bug #76093, Bug #20627890)
• The deprecated IDENTIFIED BY PASSWORD syntax is supported only for CREATE USER and
GRANT, but ALTER USER failed to reject it. ALTER USER now produces a syntax error. (Bug #76048,
Bug #20600865)
• Inappropriate -Werror options could appear in mysql_config --cflags output. (Bug #76019,
Bug #20590904)
• With InnoDB as the default temporary table storage engine, InnoDB sometimes made incorrect
assumptions about temporary table key part lengths. (Bug #76016, Bug #20590162)
• Selecting from the global_variables Performance Schema table resulted in a spurious warning
about the sql_log_bin system variable. (Bug #75980, Bug #20575529)
• For the embedded server, proper deprecation warning were not produced for SHOW VARIABLES and
SHOW STATUS statements that included a WHERE clause. (Bug #75951, Bug #20559828)
• A subquery that contained a user-defined variable could cause an assertion to be raised. (Bug
#75934, Bug #20554585)
• SET PASSWORD ... = PASSWORD('auth_string') syntax was to be deprecated in MySQL
5.7.6, but was made illegal. This syntax is now available again, but generates a warning due to its
deprecated status. These alternatives remain available, the first of which now should be considered
the preferred form:
ALTER USER ... IDENTIFIED BY 'auth_string';
SET PASSWORD ... = 'auth_string';
(Bug #75927, Bug #20552143)
• AddressSanitizer compilation errors were silenced. (Bug #75739, Bug #20459338, Bug #75740, Bug
#20459363)
• Corrections were made for a number of code issues that resulted in compiler warnings about array
bounds, possibly uninitialized variables, and variables being set but not used. (Bug #75735, Bug
#20458574)
• The mysql client could exit prematurely when invoked with the --quick option. (Bug #74182, Bug
#19723750)
• CHECK TABLE ... FOR UPGRADE did not report temporal columns that use the old datetime
format (from before MySQL 5.6.4). Consequently, mysql_upgrade did not know to issue REPAIR
TABLE statements to rebuild tables that contain such columns, and subsequent ALTER TABLE
statements were unable to perform fast alterations to the extent possible had the tables been
repaired. Now, if the avoid_temporal_upgrade system variable is disabled, CHECK TABLE
reports old temporal columns and REPAIR TABLE upgrades tables from old temporal format to the
new format. (Bug #73008, Bug #18985579)
• With the offline_mode system variable enabled, the server sometimes failed to accept connection
from a user with the SUPER privilege due to a race condition. (Bug #72760, Bug #18842228)
140
MySQL 5.7 Release Notes
• Information written to the slow query log for HANDLER ... READ statements always had
rows_sent and rows_examined values of 0. (Bug #71892, Bug #18335504)
• mysql_real_connect() could close a file descriptor twice if the server was not running. (Bug
#69423, Bug #19226740)
• Some key descriptors used by the optimizer were uninitialized. Thanks to Sergei Glushchenko for the
patch. (Bug #68713, Bug #16512701)
• EXPLAIN could show incorrect filtered values for queries that included a LIMIT clause. (Bug
#34124, Bug #11747810)
Changes in MySQL 5.7.6 (2015-03-09, Milestone 16)
Note
This is a milestone release, for use at your own risk. Upgrades between
milestone releases (or from a milestone release to a GA release) are not
supported. Significant development changes take place in milestone releases
and you may encounter compatibility issues, such as data format changes that
require attention in addition to the usual procedure of running mysql_upgrade.
For example, you may find it necessary to dump your data with mysqldump
before the upgrade and reload it afterward.
• Account Management Notes
• Compilation Notes
• Configuration Notes
• Deprecation and Removal Notes
• Generated Columns
• Installation Notes
• Optimizer Notes
• Packaging Notes
• Performance Schema Notes
• Plugin Notes
• Security Notes
• Spatial Data Support
• Functionality Added or Changed
• Bugs Fixed
Account Management Notes
• Incompatible Change: The CREATE USER and ALTER USER statements have additional accountmanagement capabilities. Together, they now can be used to fully establish or modify authentication,
SSL, and resource-limit properties, as well as manage password expiration and account locking and
unlocking. For example, ALTER USER can assign passwords, and it can modify the authentication
plugin for users, with no need for direct manipulation of the mysql.user table. For details, see
CREATE USER Syntax, and ALTER USER Syntax.
Account locking control is a new feature that permits administrators to completely disable an account
from being used to connect to the server. Account locking state is recorded in the account_locked
column of the mysql.user table. See User Account Locking.
141
MySQL 5.7 Release Notes
A new statement, SHOW CREATE USER, shows the CREATE USER statement that creates the named
user. The accompanying Com_show_create_user status variable indicates how many times the
statement has been executed.
A new system variable, log_backward_compatible_user_definitions, if enabled, causes
the server to log CREATE USER, ALTER USER, and GRANT statements in backward-compatible
(pre-5.7.6) fashion. Enabling this variable promotes compatibility for cross-version replication.
The authentication_string column in the mysql.user table now stores credential information
for all accounts. The Password column, previously used to store password hash values for accounts
authenticated with the mysql_native_password and mysql_old_password plugins, is
removed.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate the changes to the mysql database. mysql_upgrade moves
Password column values to the authentication_string column and removes the Password
column. For nonupgraded installations that have no account_locked column, the server treats all
accounts as unlocked, and attempts to lock or unlock and account produce an error.
The preceding changes make the following features obsolete. They are now deprecated and support
for them will be removed in a future MySQL release:
• Using GRANT to create users. Instead, use CREATE USER. Following this practice makes the
NO_AUTO_CREATE_USER SQL mode immaterial for GRANT statements, so it too is deprecated.
• Using GRANT to modify account properties other than privilege assignments. This includes
authentication, SSL, and resource-limit properties. Instead, establish such properties at accountcreation time with CREATE USER or modify them afterward with ALTER USER.
• IDENTIFIED BY PASSWORD 'hash_string' syntax for CREATE USER and GRANT. Instead,
use IDENTIFIED WITH auth_plugin AS 'hash_string' for CREATE USER and ALTER
USER, where the 'hash_string' value is in a format compatible with the named plugin.
• The PASSWORD() function is deprecated and should be avoided in any context. Thus,
SET PASSWORD ... = PASSWORD('auth_string') syntax is also deprecated. SET
PASSWORD ... = 'auth_string' syntax is not deprecated; nevertheless, ALTER USER is
now the preferred statement for assigning passwords.
Warning
The changes in this release result in a semantic incompatibility for one SET
PASSWORD syntax:
SET PASSWORD ... = 'literal string';
Previously, SET PASSWORD interpreted the string as a password hash
value to be stored directly. Now, SET PASSWORD interprets the string as a
cleartext string and hashes it appropriately for the account authentication
plugin before storing it.
Note
Any application that uses PASSWORD() to create hash values (a practice
that has been discouraged for some time) should be modified to use a
different hash-generation method. For suggestions, see the description of
PASSWORD() in Encryption and Compression Functions.
• The old_passwords system variable. Account authentication plugins can no longer be left
unspecified in the mysql.user table, so any statement that assigns a password from a cleartext
142
MySQL 5.7 Release Notes
string can unambiguously determine the hashing method to use on the string before storing it in
the mysql.user table. This renders old_passwords superflous.
Note
It is a known issue in this release that the following SET PASSWORD syntax
produces an error:
SET PASSWORD ... = PASSWORD('auth_string');
That syntax was to be deprecated, not removed. It will be restored in the
next release, but generate a warning due to its deprecated status. These
alternatives are available, the first of which is the preferred form:
ALTER USER ... IDENTIFIED BY 'auth_string';
SET PASSWORD ... = 'auth_string';
The change in mysql.user table structure has compatibility implications for upgrading and
downgrading:
• You can perform a binary (in-place) upgrade to MySQL 5.7.6 or later and run mysql_upgrade to
migrate the Password column contents to the authentication_string column.
• If you plan to upgrade by loading a mysqldump dump file from an older (pre-5.7.6) MySQL
installation, you must observe these conditions for the mysqldump command used to generate the
file:
• You must include the --add-drop-table option
• You must not include the --flush-privileges option
Load the pre-5.7.6 dump file into the 5.7.6 server before running mysql_upgrade.
• Because the Password column is gone in 5.7.6 and up, downgrading to a version older than 5.7.6
requires a special procedure. See Changes Affecting Downgrades from MySQL 5.7.
References: See also: Bug #67449, Bug #14845612, Bug #18140348.
Compilation Notes
• The required version of the Boost library for server builds has been raised from 1.55.0 to 1.57.0.
(Bug #74666, Bug #19940297, Bug #73432, Bug #19320102)
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Configuration Notes
• mysqld now supports a --daemonize option that causes it to run as a traditional, forking daemon.
This permits the server to work with operating systems that use systemd for process control.
Advantages include automatic restarts after failure, handling of the user and group used to run the
daemon, resource control, and temporary-file cleanup.
The new WITH_SYSTEMD CMake option, when enabled, causes installation of systemd support files.
In addition, scripts such as mysqld_safe and the System V initialization script are not installed. On
platforms where systemd is not available, enabling WITH_SYSTEMD results in an error from CMake.
When WITH_SYSTEMD is enabled, the new SYSTEMD_SERVICE_NAME and SYSTEMD_PID_DIR
options may also be used to specify the MySQL service name and directory in which the server
creates the PID file, respectively.
143
MySQL 5.7 Release Notes
Support files for systemd are installed when you install MySQL using an RPM distribution for these
Linux platforms:
• Red Hat Enterprise Linux 7; Oracle Linux 7; CentOS 7
• SUSE Linux Enterprise Server 12
• Fedora 20, 21
You also obtain systemd support by installing from a source distribution that is configured with the DWITH_SYSTEMD=1 CMake option.
To provide better information to management processes, the server now returns one of the exit
codes described in the following list. The phrase in parentheses indicates the action taken by
systemd in response to the code.
• 0 = successful termination (no restart done)
• 1 = unsuccessful termination (no restart done)
• 2 = unsuccessful termination (restart done)
Note
Any management script written for older servers should be revised to handle
three exit values if it checks only for 1 as a failure exit value.
For more information, see Managing MySQL Server with systemd. That section also includes
information about specifying options previously specified in [mysqld_safe] option groups.
Because mysqld_safe is not installed when systemd is used, such options must be specified
another way.
Deprecation and Removal Notes
• Replication: The global scope for the sql_log_bin system variable has been deprecated, and
this variable can now be set with session scope only. The statement SET GLOBAL SQL_LOG_BIN
now produces an error. It remains possible to read the global value of sql_log_bin, but doing so
produces a warning. You should act now to remove from your applications any dependencies on
reading this value; the global scope sql_log_bin is removed in MySQL 8.0. (Bug #67433, Bug
#15868071)
Generated Columns
• MySQL now supports the specification of generated columns in CREATE TABLE and ALTER TABLE
statements. Values of a generated column are computed from an expression included in the column
definition. Generated columns can be virtual (computed “on the fly” when rows are read) or stored
(computed when rows are inserted or updated). The INFORMATION_SCHEMA.COLUMNS table shows
information about generated columns.
Uses for generated columns include simplifying queries when applications select from a table using
a complex expression, simulating functional indexes, or substituting for views. For more information,
see CREATE TABLE and Generated Columns.
Installation Notes
• The mysqld server and mysql_upgrade utility have been modified to make binary (in-place)
upgrades from MySQL 5.6 easier without requiring the server to be started with special options. The
server checks whether the system tables are from a MySQL version older than 5.7 (that is, whether
the mysql.user table has a Password column). If so, it permits connections by users who have an
empty authentication plugin in their mysql.user account row, as long as they have a Password
value that is empty (no password) or a valid native (41-character) password hash.
144
MySQL 5.7 Release Notes
This means that you can connect as root and upgrade your system tables even with an older
mysql.user table for which root has no authentication plugin named. In particular, you can run
mysql_upgrade, connecting as root, with no need to start the server with any special options.
Previously, if the root account had an empty plugin value, a procedure involving starting the server
with --skip-grant-tables and multiple restarts was required. The procedure now is simpler.
1. Stop the old (MySQL 5.6) server
2. Upgrade the MySQL binaries in place (replace the old binaries with the new ones)
3. Start the MySQL 5.7 server normally (no special options)
4. Run mysql_upgrade to upgrade the system tables
5. Restart the MySQL 5.7 server
• Previously, for a new MySQL installation on Unix and Unix-like systems, initialization of the data
directory (including the tables in the mysql system database) was done using mysql_install_db.
On Windows, MySQL distributions included a data directory with prebuilt tables in the mysql
database.
mysql_install_db functionality now has been integrated into the MySQL server, mysqld. To
use this capability to initialize a MySQL installation, if you previously invoked mysql_install_db
manually, invoke mysqld with the --initialize or --initialize-insecure option,
depending on whether you want the server to generate a random password for the initial
'root'@'localhost' account.
As a result of this change, mysql_install_db is deprecated, as is the special --bootstrap
option that mysql_install_db passes to mysqld. These will be removed in a future MySQL
release. Also, the $HOME/.mysql_secret file written by mysql_install_db is no longer
needed. If it is present on your system, you can remove it.
Initializing a MySQL installation using mysqld works on all platforms, including Windows. In
particular, it is possible to initialize a Windows installation without the set of prebuilt tables for
the mysql database. (However, it is unnecessary to do so for this release because Windows
distributions still include the pre-built tables.)
For more information, see Initializing the Data Directory Manually Using mysqld.
Optimizer Notes
• To handle a derived table (subquery in the FROM clause) or view reference, the optimizer can
materialize the derived table or view reference to an internal temporary table or merge it into the
outer query block. Previously, derived tables were always materialized, whereas equivalent view
references were sometimes materialized and sometimes merged. This inconsistent treatment of
equivalent queries could lead to performance problems: Unnecessary derived table materialization
takes time and prevents the optimizer from pushing down conditions to derived tables.
The optimizer now handles derived tables in consistent fashion; that is, the same as view references.
This better avoids unnecessary materialization and enables use of pushed-down conditions
that produce more efficient execution plans. For an example, see Optimizing Subqueries with
Materialization.
The optimizer also better handles propagation of an ORDER BY clause in a derived table or view
reference to the outer query block, doing so only when this makes sense. Previously, the optimizer
always propagated ORDER BY, even if it was irrelevant or resulted in an invalid query.
For statements such as DELETE or UPDATE that modify tables, using the merge strategy for a
derived table that previously was materialized can result in an ER_UPDATE_TABLE_USED error:
145
MySQL 5.7 Release Notes
mysql> DELETE FROM t1
-> WHERE id IN (SELECT id
->
FROM (SELECT t1.id
->
FROM t1 INNER JOIN t2 USING (id)
->
WHERE t2.status = 0) AS t);
ERROR 1093 (HY000): You can't specify target table 't1'
for update in FROM clause
The error occurs when merging a derived table into the outer query block results in a statement
that both selects from and modifies a table. (Materialization does not cause the problem because,
in effect, it converts the derived table to a separate table.) To avoid this error, disable the
derived_merge flag of the optimizer_switch system variable before executing the statement:
mysql> SET optimizer_switch = 'derived_merge=off';
The derived_merge flag controls whether the optimizer attempts to merge derived tables and view
references into the outer query block, assuming that no other rule prevents merging. By default,
the flag is on to enable merging. Setting the flag to off prevents merging and avoids the error
just described. (Other workarounds include using SELECT DISTINCT or LIMIT in the subquery,
although these are not as explicit in their effect on materialization.) If an ER_UPDATE_TABLE_USED
error occurs for a view reference that uses an expression equivalent to the subquery, adding
ALGORITHM=TEMPTABLE to the view definition prevents merging and takes precedence over the
current derived_merge value.
For more information, see Optimizing Derived Tables and View References.
References: See also: Bug #20073366, Bug #59203, Bug #11766159.
Packaging Notes
• Microsoft Windows: For Windows, the noinstall Zip archive was split into two separate Zip archives.
The MySQL test suite, MySQL benchmark suite, and debugging binaries/information components
(including PDB files) were moved into their own Zip archive named mysql-VERSION-winx64debug-test.zip for 64-bit and mysql-VERSION-win32-debug-test.zip for 32-bit. This
change was made to reduce the file size of the more common download.
• Packaging scripts such as those included in RPM or Debian packages have been modified per the
principle that files installed from MySQL distributions should have the most restrictive permissions
possible. In the following description, assume that the account used to administer MySQL has owner
(user) = mysql, group = mysql.
• Installers that create the mysql account do so with a shell of /bin/false to prevent direct login
to the account.
• The data directory and its contents are owned by and accessible only to owner/group
mysql/mysql, with permissions of 750 for directories, 755 for executable files, 640 for other files.
• Others files (including executables and libraries) have owner/group of root/root, with these
permissions:
• Executables: 755
• Man pages, character set files, header files, test suite files: 644
• Library files: Conventions appropriate for the host system
Packaging scripts that perform the preceding actions for installation also perform them for upgrades,
with the exceptions that if the mysql account exists, it is left unchanged, and if the data directory
exists, its permissions and ownership are left unchanged.
146
MySQL 5.7 Release Notes
Performance Schema Notes
• The Performance Schema incorporates these changes:
• The Performance Schema now allocates memory incrementally, scaling its memory use to actual
server load, instead of allocating all the memory it needs during server startup. Consequently,
configuration of the Performance Schema is easier; most sizing parameters need not be set at
all. A server that handles a very low load will consume less memory without requiring explicit
configuration to do so.
These system variables are autoscaled:
performance_schema_accounts_size
performance_schema_hosts_size
performance_schema_max_cond_instances
performance_schema_max_file_instances
performance_schema_max_index_stat
performance_schema_max_metadata_locks
performance_schema_max_mutex_instances
performance_schema_max_prepared_statements_instances
performance_schema_max_program_instances
performance_schema_max_rwlock_instances
performance_schema_max_socket_instances
performance_schema_max_table_handles
performance_schema_max_table_instances
performance_schema_max_table_lock_stat
performance_schema_max_thread_instances
performance_schema_users_size
There are new instruments named with the prefix memory/performance_schema/ that expose
how much memory is allocated for internal buffers in the Performance Schema. These instruments
are displayed in the memory_summary_global_by_event_name table.
For more information about how Performance Schema allocates memory and how to assess the
amount currently in use, see The Performance Schema Memory-Allocation Model.
• Instrumentation for table indexes and table locks is more flexible and less memory intensive.
For a table for which index and table lock instrumentation is disabled (as specified in the
setup_objects table), the Performance Schema allocates no memory for statistics collection.
For a table for which index and table lock instrumentation is enabled, memory allocation for
statistics collection is deferred until the table begins to be used.
Configuration for instrumentation of table indexes and table locks now is exposed explicitly:
• The performance_schema_max_table_lock_stat and
performance_schema_max_index_stat system variables configure how many indexes
per table and how many table locks are subject to statistics collection. These variables are
autoscaling by default, reducing memory allocation for MySQL installations where the default
allocation was greater than necessary for a server's workload (for example, when databases
contain large numbers of tables). They can be set at startup to place explicit limits on memory
allocation.
• The Performance_schema_table_lock_stat_lost and
Performance_schema_index_stat_lost status variables enable assessing whether the
corresponding system variable settings are so low as to result in loss of instrumentation.
• System and status variable information is now available in Performance Schema tables:
• System variables: global_variables, session_variables, and variables_by_thread
contain individual system variable values.
147
MySQL 5.7 Release Notes
• Status variables: global_status, session_status, and status_by_thread,
contain individual status variable values. status_by_account, status_by_host, and
status_by_user contain session status variable values aggregated per account, host name,
and user name.
These Performance Schema tables contain information similar to that available from
the SHOW VARIABLES and SHOW STATUS statements and the GLOBAL_VARIABLES,
SESSION_VARIABLES, GLOBAL_STATUS, and SESSION_STATUS INFORMATION_SCHEMA
tables.
The Performance Schema tables offer these advantages:
• By using the variables_by_thread and status_by_thread tables, it is possible to obtain
session variables for any session, not just the current session. It is also possible to obtain only
session variables, rather than a mix of session and global variables such as returned by SHOW
SESSION VARIABLES and SHOW SESSION STATUS.
• Requests for global variables produce only global variables, whereas for the SHOW GLOBAL
STATUS statement and the GLOBAL_STATUS INFORMATION_SCHEMA table, requests produce
not only global variables, but also session variables that have no global counterpart.
• Access to the Performance Schema tables requires the SELECT privilege, whereas the SHOW
statements and INFORMATION_SCHEMA tables do not.
For more information, see Performance Schema System Variable Tables, Performance Schema
Status Variable Tables, and Status Variable Summary Tables.
The value of the new show_compatibility_56 system variable affects the output produced
from and privileges required for system and status variable statements and tables. For details, see
the description of that variable in Server System Variables.
The INFORMATION_SCHEMA tables now are deprecated in preference to the Performance Schema
tables and will be removed in a future MySQL release. For advice on migrating away from the
INFORMATION_SCHEMA tables to the Performance Schema tables, see Migrating to Performance
Schema System and Status Variable Tables.
Note
It is a known issue in this release that the session_variables and
session_status tables do not fully reflect all variable values in effect for
the current session; they include no rows for global variables that have no
session counterpart. This is corrected in MySQL 5.7.8.
• Previously, the Performance Schema enabled instrumentation for new foreground threads
if there was a row in the setup_actors table that matched the thread user and host. Now,
the setup_actors table has an ENABLED column that indicates whether or not to enable
instrumentation for matching foreground threads. This permits instrumentation for matching
threads to be disabled explicitly. For more information, see Pre-Filtering by Thread, The
setup_actors Table, and The threads Table.
• Two previously hardcoded limits on SQL statement handling are now configurable:
• The maximum number of bytes from SQL statements to display in the SQL_TEXT column of
statement event tables, such as events_statements_current.
• The number of bytes available for computing statement digests. Statement digests appear in the
DIGEST_TEXT column of statement event tables.
148
MySQL 5.7 Release Notes
Previously, both values were fixed at 1024. It is now possible to change them at server startup
using the performance_schema_max_sql_text_length and max_digest_length system
variables. (The name max_digest_length does not begin with performance_schema_
because statement digesting is now done at the SQL level even if the Performance Schema
is disabled and is available to other aspects of server operation that could benefit from it. For
example, query rewrite plugins now make use of statement digests, even if the Performance
Schema is disabled.)
The defaults remain at 1024, but the values can be reduced to use less memory or increased to
permit longer statements to be distinguished for display and digesting purposes. Each variable has
a range from 0 to 1024 × 1024.
Any bytes in excess of performance_schema_max_sql_text_length are discarded and do
not appear in the SQL_TEXT column. Statements differing only after that many initial bytes are
indistinguishable in this column.
Any bytes in excess of max_digest_length during digest computation do not factor into digest
values. Statements differing only after that many bytes of parsed statement tokens produce the
same digest and are aggregated for digest statistics.
For applications that generate very long statements that differ only at the end, the ability to change
max_digest_length variables enables computation of digests that distinguish statements that
previously were aggregated to the same digest. Conversely, administrators can devote less server
memory to digest storage by reducing the values of this variable. Administrators should keep in
mind that larger values result in correspondingly increased memory requirements, particularly for
workloads that involve large numbers of simultaneous sessions. (max_digest_length bytes are
allocated per session.)
For more information, see Performance Schema Statement Digests.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
References: See also: Bug #71057, Bug #68514, Bug #16414081.
Plugin Notes
• MySQL Server now supports query rewrite plugins:
• A preparse query rewrite plugin enables rewriting of SQL statements arriving at the server before
the server processes them. The plugin receives a statement string and may return a different
string.
• A postparse query rewrite plugin enables statement rewriting based on parse trees. The server
parses each statement and passes its parse tree to the plugin, which may traverse the tree. The
plugin can return the original tree to the server for further processing, or construct a different tree
and return that instead.
MySQL distributions now include a postparse query rewrite plugin named Rewriter. This plugin is
rule based. You can add rows to its rules table to cause SELECT statement rewriting.
One application of query rewrite plugins is to enable use of newer server capabilities with
applications that might not be subject to modification. For example, the plugin can add optimizer
hints to statements produced by an older application that cannot be changed.
For more information, see Query Rewrite Plugins, and The Rewriter Query Rewrite Plugin.
Security Notes
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MySQL 5.7 Release Notes
• Security Fix: Due to the LogJam issue (https://weakdh.org/), OpenSSL has changed the DiffieHellman key length parameters for openssl-1.0.1n and up. OpenSSL has provided a detailed
explanation at http://openssl.org/news/secadv_20150611.txt. To adopt this change in MySQL, the
key length used in vio/viosslfactories.c for creating Diffie-Hellman keys has been increased
from 512 to 2,048 bits. (Bug #77275, Bug #21221862, Bug #18367167, Bug #21307471, Bug
#21449838)
• Incompatible Change: The secure_file_priv system variable is used to limit the effect of data
import and export operations. The following changes have been made to how the server handles this
variable:
• secure_file_priv can be set to NULL to disable all import and export operations.
• The server checks the value of secure_file_priv at startup and writes a warning to the
error log if the value is insecure. A non-NULL value is considered insecure if it is empty, or the
value is the data directory or a subdirectory of it, or a directory that is accessible by all users. If
secure_file_priv is set to a nonexistent path, the server writes an error message to the error
log and exits.
• Previously, the secure_file_priv system variable was empty by default. Now the default value
is platform specific and depends on the value of the INSTALL_LAYOUT CMake option, as shown in
the following table.
INSTALL_LAYOUT Value
Default secure_file_priv Value
STANDALONE, WIN
empty
DEB, RPM, SLES, SVR4
/var/lib/mysql-files
Otherwise
mysql-files under the CMAKE_INSTALL_PREFIX value
• To specify the default secure_file_priv value explicitly if you are building from source, use the
new INSTALL_SECURE_FILE_PRIVDIR CMake option.
(Bug #24679907, Bug #24695274, Bug #24707666)
• yaSSL was upgraded to version 2.3.7. (Bug #19695101, Bug #20201864)
• To make it easier to produce the files required to support encrypted connections using SSL and
secure password exchange using RSA over unencrypted connections, MySQL distributions now
include the mysql_ssl_rsa_setup utility. This utiliy uses the openssl command, so its use is
contingent on having OpenSSL installed on your machine. When invoked, mysql_ssl_rsa_setup
checks the data directory for SSL and RSA files and uses openssl to create them if they are
missing. For more information, see mysql_ssl_rsa_setup — Create SSL/RSA Files.
Autodiscovery of key and certificate files in the data directory at startup now applies to servers
compiled using yaSSL. Previously, this applied only to servers compiled using OpenSSL. See
Configuring MySQL to Use Encrypted Connections.
If the server automatically enables encrypted connections, it writes a message to the error
log. If the server finds that the CA certificate is self-signed, it writes a warning to the error log.
(The certificate will be self-signed if created automatically by the server or manually using
mysql_ssl_rsa_setup.)
Spatial Data Support
• Spatial functions now allocate memory in larger chunks to reduce number of allocation calls and
reduce overhead. (Bug #20073459, Bug #74949)
• A new set of spatial convenience functions is available:
• ST_Distance_Sphere(): Returns the mimimum spherical distance in meters between Point or
MultiPoint arguments on a sphere.
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MySQL 5.7 Release Notes
• ST_IsValid(): Checks whether a geometry is valid.
• ST_MakeEnvelope(): Returns the rectangle that forms the envelope around two points.
• ST_Simplify(): Returns a simplified geometry.
• ST_Validate(): Returns a validated geometry, or NULL if it is invalid.
For details, see Spatial Convenience Functions.
• The spatial function namespace is being made more consistent, with the ultimate goal that each
spatial function name begins with ST_ if it performs an exact operation, or with MBR if it performs an
operation based on minimum bounding rectangles.
Currently, some functions have two implementations and up to three related names: A name with an
ST_ prefix, and a name with an MBR prefix, and a name with no prefix:
• The name with an ST_ prefix performs an exact operation.
• The name with an MBR prefix performs an operation based on minimum bounding rectangles.
• The name with neither prefix sometimes is an alias for the ST_ name (as with Area() and
ST_Area()), sometimes an alias for the MBR name (as with Contains() and MBRContains()),
This release implements the following changes in spatial function naming:
• A function with an ST_ prefix is added for each non-MBR function that has no ST_ name.
• Each function that does not begin with ST_ or MBR is deprecated.
• The exceptions are the geometry object construction functions, which remain unchanged:
Point(), LineString(), Polygon(), MultiPoint(), MultiLineString(),
MultiPolygon(), and GeometryCollection().
• These functions are deprecated in favor of the MBR names: Contains(), Disjoint(),
Equals(), Intersects(), Overlaps(), Within().
• These functions are deprecated in favor of the ST_ names: Area(), AsBinary(),
AsText(), AsWKB(), AsWKT(), Buffer(), Centroid(), ConvexHull(), Crosses(),
Dimension(), Distance(), EndPoint(), Envelope(), ExteriorRing(),
GeomCollFromText(), GeomCollFromWKB(), GeomFromText(), GeomFromWKB(),
GeometryCollectionFromText(), GeometryCollectionFromWKB(),
GeometryFromText(), GeometryFromWKB(), GeometryN(), GeometryType(),
InteriorRingN(), IsClosed(), IsEmpty(), IsSimple(), LineFromText(),
LineFromWKB(), LineStringFromText(), LineStringFromWKB(), MLineFromText(),
MLineFromWKB(), MPointFromText(), MPointFromWKB(), MPolyFromText(),
MPolyFromWKB(), MultiLineStringFromText(), MultiLineStringFromWKB(),
MultiPointFromText(), MultiPointFromWKB(), MultiPolygonFromText(),
MultiPolygonFromWKB(), NumGeometries(), NumInteriorRings(), NumPoints(),
PointFromText(), PointFromWKB(), PointN(), PolyFromText(), PolyFromWKB(),
PolygonFromText(), PolygonFromWKB(), SRID(), StartPoint(), Touches(), X(), Y().
• These ST_ names are added and are preferred over the corresponding non-ST_ names, which
now are deprecated: ST_MLineFromText(), ST_MLineFromWKB(), ST_MPointFromText(),
ST_MPointFromWKB(), ST_MPolyFromText(), ST_MPolyFromWKB(),
ST_MultiLineStringFromText(), ST_MultiLineStringFromWKB(),
ST_MultiPointFromText(), ST_MultiPointFromWKB(), ST_MultiPolygonFromText(),
ST_MultiPolygonFromWKB().
• ST_GeomCollFromTxt() is added as a synonym for ST_GeomCollFromText().
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MySQL 5.7 Release Notes
• ST_Length() is added to implement the same operation as the now-deprecated GLength(),
which has a nonstandard name because a function named Length() already existed (to calculate
string lengths).
Use of deprecated functions produces a warning. The deprecated functions will be removed in a
future MySQL release.
• Functions for checking spatial relations now use functionality available in Boost.Geometry 1.56 and
up: ST_Contains(), ST_Crosses(), ST_Disjoint(), ST_Equals(), ST_Intersects(),
ST_Overlaps(), ST_Touches(), ST_Within(). Specifically, these functions now:
• Are able to test the relationship between all pairs of argument types handled by Boost.Geometry.
• Raise an exception for invalid argument types when the previous implementation may not have.
This work also corrected issues that ST_Overlaps() returned 1 and ST_Intersects() returned
0 for two polygons that shared only a boundary, and that ST_Intersects() sometimes incorrectly
calculated the result for intersections of LineString and Polygon.
References: See also: Bug #68091, Bug #16174580, Bug #71076, Bug #17894858.
• GIS code now uses Boost.Geometry.Rtree to improve handling of geometry collection
arguments in binary GIS functions. The minimum bounding rectangles (MBRs) of geometry collection
components are used to set up an rtree index, which is used to search for possible matching
components using each MBR of the components of the other geometry collection. The results from
the rtree index search are provided to precise computation algorithms to avoid unnecessary (and
much more expensive) precise computation. As a result, the time complexity of handling geometry
collection arguments in GIS algorithms is reduced from O(N^2) to O(NlogN).
• These changes have been made for spatial functions that operate on minimum bounding rectangles
(MBRs) of geometry values:
• Two new functions test the covering relationship of two geometries using their MBRs.
MBRCovers() indicates whether the MBR of one geometry covers that of another.
MBRCoveredBy() tests the opposite, indicating whether the MBR of one geometry is covered by
that of another.
• The spatial function MBREquals() has been implemented. It should be used in preference to
MBREqual(), which is now deprecated. (The new name is more consistent with the similar
Equals() function.)
• MBRTouches() now correctly uses the geometry MBRs, not the geometries themselves.
• MBRTouches() and MBRWithin() better conform to the Open Geospatial Consortium
specification: When a point lies on the boundary of a line segment or polygon, or when a line
segment lies totally on the boundary of a polygon, it is not considered “within” but instead
“touches.” Also, two identical points are not considered “touches.”
Functionality Added or Changed
• Incompatible Change; InnoDB: The MERGE_THRESHOLD value for index pages is now configurable
using a COMMENT clause with CREATE TABLE, ALTER TABLE, and CREATE INDEX statements. If
the page-full percentage for an index page falls below the MERGE_THRESHOLD value when a row
is deleted or when a row is shortened by an UPDATE operation, InnoDB attempts to merge the
index page with a neighboring index page. The default MERGE_THRESHOLD value is 50, which is the
previously hard-coded value.
This feature adds a MERGE_THRESHOLD column to the internal SYS_INDEXES table. SYS_INDEXES
records for tables that were originally created in 5.7.5 or earlier do not include this column.
Rebuilding or importing these tables after upgrading to MySQL 5.7.6 or later properly updates
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MySQL 5.7 Release Notes
SYS_INDEXES records with the new MERGE_THRESHOLD column. Otherwise, TRUNCATE TABLE
or ALTER TABLE ... RENAME INDEX operations followed by a server restart or a table reload
causes errors. This bug is fixed in MySQL 5.7.8 (Bug #20882432).
For more information, see Configuring the Merge Threshold for Index Pages.
• Incompatible Change: A new C API function, mysql_real_escape_string_quote(), has
been implemented as a replacement for mysql_real_escape_string() because the latter
function can fail to properly encode characters when the NO_BACKSLASH_ESCAPES SQL mode is
enabled. In this case, mysql_real_escape_string() cannot escape quote characters except by
doubling them, and to do this properly, it must know more information about the quoting context than
is available. mysql_real_escape_string_quote() takes an extra argument for specifying the
quoting context. For usage details, see mysql_real_escape_string_quote().
Note
Applications should be modified to use
mysql_real_escape_string_quote(), instead of
mysql_real_escape_string(), which now fails and produces an
CR_INSECURE_API_ERR error if NO_BACKSLASH_ESCAPES is enabled.
References: See also: Bug #19211994.
• InnoDB: All remaining code related to the innodb_file_io_threads system variable, which was
removed in MySQL 5.5, was removed from the source code. (Bug #19843885)
• InnoDB: InnoDB system tablespace data is now exposed in the INNODB_SYS_TABLESPACES and
INNODB_SYS_DATAFILES Information Schema tables.
• InnoDB: To modularize and decouple the partitioning engine from the server code base, partitioning
operations in the storage engine handler class were moved to a new partition_handler base
class, which is now the interface for partitioning-specific storage engine functionality.
• InnoDB: InnoDB now supports the creation of general tablespaces using CREATE TABLESPACE
syntax.
CREATE TABLESPACE `tablespace_name`
ADD DATAFILE 'file_name.ibd'
[FILE_BLOCK_SIZE = n]
General tablespaces can be created outside of the MySQL data directory, are capable of holding
multiple tables, and support tables of all row formats.
Tables are added to a general tablespace using CREATE TABLE tbl_name ... TABLESPACE
[=] tablespace_name or ALTER TABLE tbl_name TABLESPACE [=] tablespace_name
syntax.
For more information, see CREATE TABLESPACE Syntax.
• InnoDB: InnoDB now supports native partitioning. Previously, InnoDB relied on the ha_partition
handler, which creates a handler object for each partition. With native partitioning, a partitioned
InnoDB table uses a single partition-aware handler object. This enhancement reduces the amount of
memory required for partitioned InnoDB tables.
The following changes accompany InnoDB native partitioning support:
• Partition definition (.par) files are no longer created for partitioned InnoDB tables. Partition
definitions are stored in the InnoDB internal data dictionary. Partition definition (.par) files
continue to be used for partitioned MyISAM tables.
• For partitioned InnoDB tables, FLUSH TABLES does not reset the “next” AUTO_INCREMENT
value. Instead, the next AUTO_INCREMENT value is kept and used after the FLUSH TABLES
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MySQL 5.7 Release Notes
operation. If the highest AUTO_INCREMENT value is deleted before a FLUSH TABLES operation, it
is not reused afterwards.
• Minor changes to statistics could result in changed execution plans.
• The minimum number of rows estimated for a partitioned InnoDB table is 1 instead of 2.
• The minimum number of rows estimated for range read on a partitioned InnoDB table index is 0
per partition instead of 1.
• Instead of only including the largest partitions when calculating matching rows in an index range,
all partitions in the read set (after pruning is completed) are included. As a result, statistics for
matching index rows are more accurate, but time spent during the Optimizer phase may increase
for tables with numerous partitions.
• InnoDB: The following buffer pool flushing-related enhancements are included in MySQL 5.7.6:
• The adaptive flushing algorithm flushes all pages at the end of the flush list if there is a high
distribution of pages associated with the oldest LSN.
• Once redo space reaches 30% full, a pre-scan on buffer pool instances determines the oldest
modified pages in each buffer pool instance. Based on this information, the adaptive flushing
algorithm determines the number of pages to flush from each buffer pool instance during a single
flush pass. This approach helps ensure that the oldest modified pages are flushed first.
• On Linux platforms where it is possible and where the mysqld execution user is authorized, the
setpriority() system call is used to give page_cleaner threads priority over other MySQL/
InnoDB threads to help page flushing keep pace with the current workload. mysqld execution
user authorization can be configured in /etc/security/limits.conf. Refer to your Linux
operating system documentation for more information.
• When the oldest modification LSN is close to the defined maximum (max_modified_age_sync),
a synchronous preflush of buffer pool pages is initiated which may result in a “flush wait”
scenario for user threads. To smooth throughput, user threads are only required to wait for a
target LSN to be reached instead of waiting for an entire flushing batch to finish. User thread
waits are reported as sync flush waits by the buffer_flush_sync_waits metric of the
INFORMATION_SCHEMA.INNODB_METRICS table.
• A block was added to prevent the log write mechanism from overwriting last checkpoint LSN.
• A message is printed to the server error log if the innodb_io_capacity_max setting is too high.
• New metrics for monitoring page_cleaner thread activity were added to the INNODB_METRICS
table:
• buffer_flush_adaptive_avg_pass: Number of adaptive flushes passed during the recent
Avg period.
• buffer_flush_adaptive_avg_time_est: Estimated time (ms) spent for adaptive flushing
recently.
• buffer_flush_adaptive_avg_time_slot: Avg time (ms) spent for adaptive flushing
recently per slot.
• buffer_flush_adaptive_avg_time_thread: Avg time (ms) spent for adaptive flushing
recently per thread.
• buffer_flush_avg_pass: Number of flushes passed during the recent Avg period.
• buffer_flush_avg_time: Avg time (ms) spent for flushing recently.
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MySQL 5.7 Release Notes
• buffer_flush_n_to_flush_by_age: Number of pages targeted by LSN Age for flushing.
• buffer_LRU_batch_flush_avg_pass: Number of LRU batch flushes passed during the
recent Avg period.
• buffer_LRU_batch_flush_avg_time_est: Estimated time (ms) spent for LRU batch
flushing recently.
• buffer_LRU_batch_flush_avg_time_slot: Avg time (ms) spent for LRU batch flushing
recently per slot.
• buffer_LRU_batch_flush_avg_time_thread: Avg time (ms) spent for LRU batch flushing
recently per thread.
• buffer_LRU_get_free_loops: Total loops in LRU get free.
• buffer_LRU_get_free_waits: Total sleep waits in LRU get free.
• InnoDB: The Performance Schema now instruments stage events for monitoring InnoDB ALTER
TABLE and buffer pool load operations. The new stage events include:
• stage/innodb/alter table (read PK and internal sort)
• stage/innodb/alter table (merge sort)
• stage/innodb/alter table (insert)
• stage/innodb/alter table (flush)
• stage/innodb/alter table (log apply index)
• stage/innodb/alter table (log apply table)
• stage/innodb/alter table (end)
• stage/innodb/buffer pool load
For more information, see InnoDB Integration with MySQL Performance Schema, and Saving and
Restoring the Buffer Pool State.
• InnoDB: Replication-related support was added to InnoDB which enables prioritization of slave
applier transactions over other transactions in deadlock scenarios. This transaction prioritization
mechanism is reserved for future use.
• InnoDB: CHECK TABLE functionality was enhanced for InnoDB SPATIAL indexes. Previously,
CHECK TABLE only performed minimal checks on InnoDB SPATIAL indexes. Enhanced
functionality includes an R-tree validity check and a check to ensure that the R-tree row count
matches the clustered index.
• InnoDB: The default setting for the internal_tmp_disk_storage_engine option, which defines
the storage engine the server uses for on-disk internal temporary tables, is now INNODB. With this
change, the Optimizer uses the InnoDB storage engine instead of MyISAM for internal temporary
tables. For related information, see Internal Temporary Table Use in MySQL.
• InnoDB: InnoDB now supports 32KB and 64KB page sizes. For both page sizes, the maximum
record size is 16KB. ROW_FORMAT=COMPRESSED is not supported when innodb_page_size is set
to 32k or 64k. For innodb_page_size=32k, extent size is 2MB. For innodb_page_size=64k,
extent size is 4MB. The innodb_log_buffer_size default value was increased from 8M to 16M
to support the new page sizes. innodb_log_buffer_size should be at least 16M when using a
32k or 64k page size.
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MySQL 5.7 Release Notes
• InnoDB: To support future development, the code that initializes, validates and handles tablespace
and table flags was refactored. Also, the fil_create_ibd_tablespace function was refactored,
and some functions and variables related to single tablespaces were renamed.
• Replication: The variable binlogging_impossible_mode has been renamed
binlog_error_action. binlogging_impossible_mode is now deprecated. (Bug #19507567)
• Replication: When using InnoDB with binary logging enabled, concurrent transactions
written in the InnoDB redo log are now grouped together before synchronizing to disk when
innodb_flush_log_at_trx_commit is set to 1, which reduces the amount of synchronization
operations. This can lead to improved performance. (Bug #19424075)
• Replication: Added a number of features and enhancements relating to Performance Schema and
group replication. These additions are listed here:
• The replication_group_members and replication_group_member_stats Performance
Schema tables.
• The START GROUP_REPLICATION and STOP GROUP_REPLICATION SQL statements.
• A GROUP_NAME column to the replication_connection_status table.
• The transaction_write_set_extraction system variable.
• A number of errors and error mesages.
• Replication: There is now a Previous_gtids event in every binary log, regardless of the value of
gtid_mode. In previous versions, it was only generated when gtid_mode=on. Similarly, there is
now an Anonymous_gtid event before every transaction when gtid_mode=off. These changes
ensure that similar per-transaction events are generated regardless of the type of binary logging
in use. As well as enabling the newly added ability to change gtid_mode online, this also has a
positive impact on the recovery of gtid_purged and gtid_executed.
• Replication: A new more general purpose parallelization algorithm is now used when
slave_parallel_type=LOGICAL_CLOCK, replacing the previous algorithm that was limited to
transactions on different databases. This improves throughput when transactions on the master do
not depend on each other. Now even two concurrent transactions on a master can execute in parallel
on a slave, if they hold all of their locks on the master. Additionally, transaction dependency is now
tracked on the slave through extra fields added to replication transactions in the binary log.
• Replication: It is now possible to change replication mode without having to shut down the server or
synchronize the topology. As part of this feature, the following changes have been made:
• The variable gtid_mode is now dynamic. It can be set by SUPER from a top-level statement. The
states OFF_PERMISSIVE and ON_PERMISSIVE have been added.
• The variable enforce_gtid_consistency is now dynamic. It can be set by SUPER from a toplevel statement.
• The status variable Ongoing_anonymous_transaction_count has been introduced. This
shows the number of ongoing transactions which have been marked as anonymous.
• The status variables Ongoing_anonymous_gtid_violating_transaction_count
and Ongoing_automatic_gtid_violating_transaction_count have been
introduced in debug-enabled builds. They are not available in non-debug builds. These
variables count the number of ongoing transactions that violate GTID consistency, which use
gtid_next=ANONYMOUS and gtid_next=AUTOMATIC, respectively.
For more information, see Changing Replication Modes on Online Servers
• Replication: MySQL Multi-Source Replication adds the ability to replicate from multiple masters to
a slave. MySQL Multi-Source Replication topologies can be used to back up multiple servers to a
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MySQL 5.7 Release Notes
single server, to merge table shards, and consolidate data from multiple servers to a single server.
See MySQL Multi-Source Replication.
As part of MySQL Multi-Source Replication, replication channels have been added. Replication
channels enable a slave to open multiple connections to replicate from, with each channel being
a connection to a master. To enable selection of particular channels, replication-related SQL
statements now support an optional FOR CHANNEL channel clause. See Replication Channels.
• Undocumented functions in the C client library are now hidden. This helps minimize namespace
pollution, and permits linking for applications that require functions both from yaSSL (in the client
library) and from OpenSSL. (Bug #20476596, Bug #18427840)
• CMake support was updated to handle CMake version 3.1. (Bug #20344207)
• Previously, debug builds on Windows were built with /Ob0, which disables function inlining. Builds
now use /Ob1 to enable inlining. The new WIN_DEBUG_NO_INLINE CMake option can be used
to control inlining. The default value is OFF (inlining enabled); if set to ON, inlining is disabled. (Bug
#20316320)
• The new -DWITH_UBSAN=ON CMake option enables the Undefined Behavior Sanitizer. This feature
is supported by GCC 4.9 and up, and Clang 3.4 and up. (Bug #19587393)
• The valid date range of the SSL certificates in mysql-test/std_data has been extended to the
year 2029. (Bug #18366947)
• Overhead was reduced for queries such as tested by the sysbench “order-by-range” test. (Bug
#75390, Bug #20296891)
• The mysql client program now supports \C in the prompt command to signify the current
connection identifier. Thanks to Tsubasa Tanaka for the patch. (Bug #75242, Bug #20227145)
• The server now includes its version number when it writes the initial “starting” message to the error
log, to make it easier to tell which server instance error log output applies to. This value is the same
as that available from the version system variable. (Bug #74917, Bug #20052694)
• Previously, the auth_socket authentication plugin checked the socket user name only against
the MySQL user name specified by the client program to the server. Now, if those names do
not match, the plugin also checks whether the socket user name matches the name specified in
the authentication_string column of the mysql.user table row. The plugin permits the
connection for a match in either case. Thanks to Daniël van Eeden for the patch. (Bug #74586, Bug
#20041925)
• The libmysqlclient version number has been incremented to 20.0.0. (Bug #74206, Bug
#19729266)
• A new CMake option, WITH_MSCRT_DEBUG, is available to control Visual Studio CRT memory leak
tracing. The default is OFF. (Bug #73064, Bug #19031370)
• Beginning with MySQL 5.7.2, the server disables at startup any account that has no authentication
plugin. The server now writes a more extensive message to the error log in this case to indicate how
to reenable such accounts. (Bug #73026, Bug #19011337)
• ALTER TABLE did not take advantage of fast alterations that might otherwise apply to the operation
to be performed, if the table contained temporal columns found to be in pre-5.6.4 format (TIME,
DATETIME, and TIMESTAMP columns without support for fractional seconds precision). Instead, it
upgraded the table by rebuilding it. Two new system variables enable control over upgrading such
columns and provide information about them:
• avoid_temporal_upgrade controls whether ALTER TABLE implicitly upgrades temporal
columns found to be in pre-5.6.4 format. This variable is disabled by default. Enabling it causes
ALTER TABLE not to rebuild temporal columns and thereby be able to take advantage of possible
fast alterations.
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MySQL 5.7 Release Notes
• show_old_temporals controls whether SHOW CREATE TABLE output includes comments to
flag temporal columns found to be in pre-5.6.4 format. Output for the COLUMN_TYPE column of the
INFORMATION_SCHEMA.COLUMNS table is affected similarly. This variable is disabled by default.
Both variables are deprecated and will be removed in a future MySQL release. (Bug #72997, Bug
#18985760)
• The minimum value of the stored_program_cache system variable has been changed from 256
to 16, to enable configuration of a smaller amount of memory devoted to the stored program cache.
(Bug #72451, Bug #18661573)
• The code in my_strnxfrm_simple() was suboptimal and was improved. Thanks to Alexey
Kopytov for the patch. (Bug #68476, Bug #16403708)
• The metadata locking subsystem (see Metadata Locking) has been extended to cover concurrent
access to tablespaces. This includes DDL statements that explicitly affect tablespaces: ALTER
TABLESPACE, CREATE TABLESPACE, and DROP TABLESPACE. It also includes DDL statements
that affect tablespace contents: ALTER TABLE, CREATE INDEX, CREATE TABLE, DROP INDEX,
DROP TABLE, LOCK TABLES, RENAME TABLE, and TRUNCATE TABLE.
• For queries that combine ORDER BY with LIMIT, the optimizer may switch to an index that applies to
the ORDER BY. In some cases, the decision to switch was based on a heuristic rather than on cost.
The optimizer now uniformly makes the decision whether to switch on a cost basis. This should result
in better performanance when switching would cause a query to read an entire index or a large part
of it to find qualifying rows.
References: See also: Bug #78993, Bug #22108385, Bug #73837, Bug #19579507, Bug #16522053.
• Server and client errors are numbered in ranges beginning from 1000 and 2000, respectively.
However, server error numbers are approaching 2000, leading to a potential conflict with client error
numbers. To deal with this, server error numbers for MySQL 5.7 now have a range beginning with
3000. This is implemented by permitting multiple start-error-number N lines in sql/share/
errmsg-utf8.txt, with each such line resetting the numbering to N.
• Refactoring within the optimizer resulted in the following improvements to EXPLAIN output:
• Output that showed ORDER BY col_name for implicitly grouped queries no longer does so.
• Output for INSERT statements involving partition pruning now shows only the partitions actually
used, not all partitions in the table.
• Output for UPDATE, INSERT, or DELETE statements no longer shows “Using join buffer” in cases
when join buffering was not used.
In addition, for killed queries where the previously returned error was “Unknown error”, the error is
now “Query execution was interrupted”.
References: See also: Bug #70553, Bug #17575172.
• MySQL now provides a built-in ngram full-text parser plugin that supports Chinese, Japanese, and
Korean (CJK), and an installable MeCab full-text parser plugin for Japanese. The parser plugins can
be used with InnoDB and MyISAM tables.
The built-in MySQL full-text parser uses the white space between words as a delimiter to determine
where words begin and end, which is a limitation of the built-in MySQL full-text parser for ideographic
languages that do not use word delimiters. The addition of ngram and MeCab full-text parser plugins
address this limitation.
For more information see ngram Full-Text Parser, and MeCab Full-Text Parser Plugin.
158
MySQL 5.7 Release Notes
• The plugin and servers tables in the mysql system database now are InnoDB (transactional)
tables. Previously, these were MyISAM (nontransactional) tables.
In consequence of this change, INSTALL PLUGIN and UNINSTALL PLUGIN are now included
among the statements that cause an implicit commit (see Statements That Cause an Implicit
Commit).
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the mysql database.
• The following items are deprecated and will be removed in a future MySQL release. Where
alternatives are shown, applications should be updated to use them.
• The ENCRYPT(), DES_ENCRYPT(), and DES_DECRYPT() functions, the --des-key-file
option, the have_crypt system variable, the DES_KEY_FILE option for the FLUSH statement,
and the HAVE_CRYPT CMake option. Consider using AES_ENCRYPT() and AES_DECRYPT()
instead.
• The sync_frm system variable. This variable will be removed when .frm files become obsolete.
• The global character_set_database and collation_database system variables are
deprecated and will be removed in a future version of MySQL.
Assigning a value to the session character_set_database and collation_database
system variables is deprecated and assignments produce a warning. The session variables will
become read only in a future version of MySQL and assignments will produce an error. It will
remain possible to access the session variables to determine the database character set and
collation for the default database.
• Conversion of pre-MySQL 5.1 database names containing special characters to 5.1 format with
the addition of a #mysql50# prefix. (For information about these conversions, see Mapping of
Identifiers to File Names.) Because such conversions now are deprecated, the --fix-db-names
and --fix-table-names options for mysqlcheck and the UPGRADE DATA DIRECTORY NAME
clause for the ALTER DATABASE statement are also deprecated.
Upgrades are supported only from one major version to another (for example, 5.0 to 5.1, or 5.1
to 5.5), so there should be little remaining need for conversion of older 5.0 database names to
current versions of MySQL. As a workaround, upgrade a MySQL 5.0 installation to MySQL 5.1
before upgrading to a more recent release.
• The session_track_gtids system variable was added, which enables a tracker that captures
GTIDs and appends them to the OK packet.
From the C API, GTID information can be obtained by passing SESSION_TRACK_GTIDS as the
type argument to the mysql_session_track_get_first() function.
Bugs Fixed
• Incompatible Change; InnoDB: If your system contains tablespace data files created prior to
MySQL 5.1, read this note carefully before upgrading to MySQL 5.7.6.
Tablespace data files created prior to MySQL 5.1 sometimes contain garbage
FIL_PAGE_TYPE values in some pages. To address this issue, a new file page type constant
(FIL_PAGE_TYPE_UNKNOWN) was added, and unknown FIL_PAGE_TYPE values are now reset to
FIL_PAGE_TYPE_UNKNOWN.
However, you may still encounter a failure when a non-index page that contains an invalid
FIL_PAGE_INDEX or FIL_PAGE_RTREE value in the FIL_PAGE_TYPE field is written to disk. You
can address the failure by modifying the data file to replace the invalid FIL_PAGE_TYPE values with
FIL_PAGE_UNKNOWN. The error log message provides the tablespace ID and page number of the
page with the invalid FIL_PAGE_TYPE value.
159
MySQL 5.7 Release Notes
Before MySQL 5.6, InnoDB page size is always 16384 bytes. FIL_PAGE_TYPE is defined as 24.
So, if page number P of a tablespace data file is affected, the data at byte offset 16384*P+24 should
contain the bytes 0x45 0xbf (FIL_PAGE_INDEX) or 0x45 0xbe (FIL_PAGE_RTREE). Replace
these bytes with 0x00 0x0d (FIL_PAGE_UNKNOWN).
If the page contains the strings infimum and supremum at byte offset 99 or 101 (75 or 77 bytes
after the start of the FIL_PAGE_TYPE), the page could be an index page, and there may be actual
corruption.
Warning
Do not attempt to modify data files directly unless you know exactly what you
are doing and fully understand the implications. Manually modifying the data
file is no longer required in MySQL 5.7.7 with the fix for Bug #20691930.
If FIL_PAGE_TYPE is reset to FIL_PAGE_TYPE_UNKNOWN in your pre-MySQL 5.5 data file, you may
encounter a page corruption error when restarting the server. The error is due to a FIL_PAGE_TYPE
field in the InnoDB page checksum that is still set to the previous FIL_PAGE_TYPE value. To
address the error, rewrite the page checksum using the innochecksum tool. The patch for Bug
#20691930 in MySQL 5.7.7 addresses this problem by recomputing the page checksum after
resetting the FIL_PAGE_TYPE value. (Bug #17345513, Bug #17332603, Bug #19658698)
• InnoDB; Microsoft Windows: On Windows, renaming a FULLTEXT search file name raised an
assertion. (Bug #20001827)
• InnoDB; Microsoft Windows: The logic used to select native asynchronous I/O (AIO) on Windows
was simplified. All Windows versions supported by MySQL 5.7 now support native AIO. The logic
required to handle older Windows versions that do not support native AIO was no longer necessary.
(Bug #19803939)
• InnoDB: Opening and closing of optimized temporary tables caused a negative table reference
count in InnoDB Monitor output. (Bug #20608113)
• InnoDB: A duplicate database page corruption error message was removed from buf0buf.cc.
(Bug #20605167)
• InnoDB: The NAME column of the INFORMATION_SCHEMA.INNODB_TEMP_TABLE_INFO table was
incorrectly declared as 192 characters wide. The correct length is 64 characters. (Bug #20512578)
• InnoDB: A full-text phrase search returned an incorrect result. An empty string was handled
incorrectly when tokenizing a newly inserted row. (Bug #20465273, Bug #75755)
• InnoDB: A workaround introduced in MySQL 5.7.0, in the patch for Bug #14658648, was removed.
The workaround allowed MySQL to disable the query cache during crash recovery. Inconsistent
data could be produced during crash recovery if MySQL crashed while XA transactions were in a
PREPARED state with the query cache enabled. The bug was fixed in MySQL 5.7.2 by the patch for
Bug #16593427. (Bug #20461632)
• InnoDB: In debug builds, assertion code related to buffer pool resizing caused a significant increase
in Valgrind testing time. (Bug #20461123)
• InnoDB: The use of change buffering for a spatial index raised an assertion. Change buffer flags
should not be set for spatial indexes. (Bug #20452564, Bug #75718)
• InnoDB: On ALTER TABLE ... IMPORT TABLESPACE, there was a missing dictionary unlock call
on Out-Of-Memory(OOM) that could result in a failure when allocating memory for a .ibd file path
string. (Bug #20430105)
• InnoDB: An undefined reference error occurred when building MySQL with
DWITH_EXTRA_CHARSETS=none. (Bug #20429800)
160
MySQL 5.7 Release Notes
• InnoDB: Optimizing a FULLTEXT index raised an assertion. The last optimized word of a FULLTEXT
index is stored in the CONFIG table value column which is defined as CHAR(50). An assertion was
raised when the last optimized word was greater than 50 characters in length. The CONFIG table
value column is defined as CHAR(200) as of MySQL 5.6.24 and MySQL 5.7.6.
If your innodb_ft_max_token_size setting is greater than 50, it is recommended that you
recreate existing InnoDB FULLTEXT indexes after upgrading to MySQL 5.6.24 or MySQL 5.7.6 to
avoid this issue. FULLTEXT indexes created after upgrading to MySQL 5.6.24 or MySQL 5.7.6 are
unaffected. (Bug #20418326)
• InnoDB: The innodb_optimize_point_storage option and related internal data types
(DATA_POINT and DATA_VAR_POINT) were removed. (Bug #20415831)
• InnoDB: fts_optimize_thread() set a NULL exit_event when the server started to shut
down, and before fts_optimize_thread was started. (Bug #20389745)
• InnoDB: The memcached process_arithmetic_command raised an assertion. The wrong error
code was returned for a nonexistent decr key. (Bug #20386835)
• InnoDB: The expiration time (exptime) defined using the memcached set command was ignored.
InnoDB memcached set the expiration time to an interval value instead of a system time value. (Bug
#20381342, Bug #70055)
• InnoDB: A NaN value in the GIS-related mbr_join_square function raised an assertion. (Bug
#20379160)
• InnoDB: The innobase_close_thd function and related wrapper functions and pointers were
removed. The functions and pointers were introduced with the InnoDB memcached plugin but never
used. (Bug #20369370)
• InnoDB: An assertion was raised when the full-text search fts_savepoint_release() function
released a named transaction savepoint and all subsequent savepoints. Only the initial savepoint
should be released. (Bug #20341916)
• InnoDB: Table names were displayed inconsistently in diagnostic output for InnoDB tables that
store persistent statistics. (Bug #20330831)
• InnoDB: The INFORMATION_SCHEMA.TABLES UPDATE_TIME field, enabled for InnoDB tables in
MySQL 5.7.2, was not updated for XA COMMIT of recovered transactions that were in XA PREPARE
state. (Bug #20303205)
• InnoDB: An incorrect expression was used in /storage/innobase/trx/trx0trx.cc. trx>lock.rec_pool.empty() was used instead of trx->lock.table_pool.empty(). (Bug
#20294158, Bug #75373)
• InnoDB: In /storage/innobase/handler/ha_innodb.cc, a va_end() was missing in returns
that were added in MySQL 5.7.5. (Bug #20285744, Bug #75323)
• InnoDB: A full-text search optimization operation raised an assertion. (Bug #20281800)
• InnoDB: A tablespace export operation set the purge state to PURGE_STATE_STOP, but the purge
thread did not check the purge state until the current purge operation was completed. In the case
of a large history list, the tablespace export operation was delayed, waiting for the current purge
operation to finish. The purge state is now checked with every purge batch. (Bug #20266847, Bug
#75298)
• InnoDB: When a page is read from disk, there is a check for pending insert buffer entries which
involves acquiring a latch on the insert buffer page. If pending entries are found, they are merged.
Because the change buffer is only applicable to B-tree secondary leaf pages in non-temporary
tablespaces, insert buffer merge is not necessary for all page types. Using page_type, page_level,
and tablespace type information from the page that is read from disk, insert buffer merge is now
skipped for non-applicable page types. (Bug #20220909)
161
MySQL 5.7 Release Notes
• InnoDB: The name of the internal pseudo-tablespace that is created for the InnoDB redo log was
changed from ib_logfile101 to innodb_redo_log. The new name aligns with other MySQL 5.7
internal tablespace names that use an “innodb_” prefix. (Bug #20204978)
• InnoDB: An ALTER TABLE ... ADD INDEX operation raised an assertion due to assertion code
that did not allow an online index status of ONLINE_INDEX_ABORTED_DROPPED. The assertion code
was relaxed. (Bug #20198726)
• InnoDB: Attempting to access the table name for a table that was NULL due to a prior inconsistency
caused a crash in innobase_update_foreign_cache() when printing an error. (Bug
#20146176)
• InnoDB: An error occurred when the push_warning_printf function was invoked during
server recovery. This function was previously used to print a warning message to the client. Also,
current_thd was NULL when the server was restarted. (Bug #20144839)
• InnoDB: The last flushing loop on shutdown did not call buf_flush_wait_LRU_batch_end(),
resulting in an assertion failure. (Bug #20137435)
• InnoDB: The dict_index_t::auto_gen_clust_index flag, which was used inconsistently and
redundant, was removed. (Bug #20136192)
• InnoDB: A memory access violation in fts_optimize_thread caused the server to halt. A table
was freed but not removed from the full-text search optimize queue. (Bug #20125560)
• InnoDB: An assertion was raised while updating statistics for referenced tables after a cascade
update. (Bug #20125466)
• InnoDB: A crash occurred in btr_cur_latch_leaves while performing a load operation.
Checking the page state without latching the page caused an inconsistency. The page state should
only be checked after the page is latched. (Bug #20111105, Bug #74596)
• InnoDB: The INNODB_METRICS adaptive_hash_searches_btree counter failed to report
counter data. (Bug #20080942, Bug #74511)
• InnoDB: Due to a regression introduced in MySQL 5.6.20, mysqld stop did not stop the mysqld
server process while the InnoDB memcached plugin was active. (Bug #20078646, Bug #74956)
References: This issue is a regression of: Bug #18409840.
• InnoDB: The commit_node member from the tab_node_t and ind_node_t query graph objects,
used during table and index creation, were removed. The commit_node member was initialized but
never used. Unused TABLE_COMMIT_WORK and INDEX_COMMIT_WORK execution steps were also
removed. (Bug #20060218)
• InnoDB: An ALTER TABLE ... RENAME failure on a table with a FULLTEXT index raised an
assertion. (Bug #20043707)
• InnoDB: A duplicate key error encountered during a REPLACE operation on a temporary table raised
an assertion. (Bug #20040791)
• InnoDB: An ALTER TABLE operation that changed the name of a foreign key column resulted in a
failure when reloading the foreign key constraint. The previous column name remained in the data
dictionary cache instead of being evicted. (Bug #20031243)
• InnoDB: ALTER TABLE failed to check if the table is corrupted. An ALTER TABLE operation that
affects InnoDB metadata should be refused if the clustered index is corrupted or the table is marked
as corrupted. An ALTER TABLE operation should also be refused if the table is not rebuilt and a
corrupted secondary index would remain after the ALTER TABLE operation. (Bug #20015132, Bug
#74810)
• InnoDB: A row update operation raised an assertion in row_upd_sec_index_entry(). In
row_merge_read_clustered_index(), the cached spatial index was not inserted prior to the
162
MySQL 5.7 Release Notes
mini-transaction commit. Once the mini-transaction was committed, the clustered index page was
updated or freed, resulting in the primary key fields for cached spatial index entries pointing to invalid
addresses. (Bug #19999469)
• InnoDB: An assertion was raised in the btr_cur_search_to_nth_level function. Both shared
locks (s-locks) and shared-exclusive locks (sx-locks) should be permitted for all latch modes. (Bug
#19984494)
• InnoDB: An ALTER TABLE operation on a table with a FULLTEXT index raised an assertion. The
table was already present in the cache and the FULLTEXT indexes were already initialized. When
the table was reloaded, the FULLTEXT indexes were initialized again, causing the assertion. (Bug
#19978288)
• InnoDB: An UPDATE operation on a compressed temporary table raised an assertion. Shared
temporary tablespace attributes were used when extending the tablespace for a compressed
temporary table. (Bug #19976331)
• InnoDB: Error messages regarding a size limitation on BLOB or TEXT data inserted in a single
transaction were revised. (Bug #19975322)
• InnoDB: Server logs reported a vector subscript out of range error. (Bug #19955501)
• InnoDB: CHECK TABLE failed to check if the table is in a corrupt state before performing validation,
resulting in an assertion. (Bug #19954054)
• InnoDB: To avoid I/O on tablespaces that are rarely written to, the
fsp_get_available_space_in_free_extents function now accesses metadata from cached
fields instead of the tablespace header page in the buffer pool.
This patch also includes the following optimizations:
• To avoid lookups, fsp_fill_free_list() and some other functions now take a fil_space_t
pointer instead of a numeric tablespace identifier.
• The fil_extend_space_to_desired_size function was renamed to fil_space_extend
and its API was simplified.
• A new method, undo::Truncate::was_tablespace_truncated, was added to avoid a
consistency check before flushing of truncated undo tablespace files.
(Bug #19949683)
• InnoDB: A failed DROP TABLE operation could leave a table in an inconsistent state without marking
the table as corrupted. (Bug #19946781, Bug #74676)
• InnoDB: A wrapper class was added to improve printing of quoted SQL identifiers, such as index,
column and tablespace names. (Bug #19933607)
• InnoDB: An ALTER TABLE operation raised an assertion. When a foreign key object was removed
from the dictionary cache, an incorrect foreign key object was removed from the rb-tree. (Bug
#19908343)
References: This issue is a regression of: Bug #18806829.
• InnoDB: DML operations on a table with full-text search indexes raised an invalid assertion. (Bug
#19905246)
References: This issue is a regression of: Bug #19314480.
• InnoDB: A missing DBUG_RETURN() in ha_innobase::update_row raised an assertion. (Bug
#19904800)
163
MySQL 5.7 Release Notes
• InnoDB: In debug builds, setting the innodb_limit_optimistic_insert_debug debug
configuration option to 1 caused an infinite B-tree page split. (Bug #19904003, Bug #74605)
• InnoDB: An ALTER TABLE ... DROP PRIMARY KEY, ADD PRIMARY KEY operation that
changed the prefix length of the primary key field raised an assertion in the bulk insert code. (Bug
#19896922)
• InnoDB: Some InnoDB diagnostic output to stderr included unnecessary line breaks and lines
without a preceding timestamp. Output from multiple threads could become interleaved due to
messages being written out in several non-atomic steps. (Bug #19895222)
• InnoDB: The innodb_create_intrinsic option, introduced in MySQL 5.7.5, was removed. (Bug
#19893327)
• InnoDB: As of MySQL 5.7.5, MySQL builds depend on atomic memory access primitives being
present on the target platform. To simplify the code, HAVE_ATOMIC_BUILTINS was removed from
the InnoDB source in MySQL 5.7.6. InnoDB now depends on Microsoft atomics on Windows, and
on GCC-style atomics on other platforms. (Bug #19856411)
• InnoDB: A severe error occurred during the log apply phase of an online ALTER TABLE operation
that was converting a table with a UTF-8 charset to ROW_FORMAT=REDUNDANT. (Bug #19843246,
Bug #19895661, Bug #20219871)
• InnoDB: A multiple-table delete operation caused the server to halt. (Bug #19815702)
• InnoDB: A buffer pool dump referred to a non-existing tablespace ID. (Bug #19814155)
References: This issue is a regression of: Bug #19149177.
• InnoDB: In debug builds, buf_block_align() could be called from debug assertion code while
the buffer pool is being resized, resulting in a race condition. (Bug #19803497)
• InnoDB: A FLUSH TABLES operation raised an assertion. (Bug #19803418)
• InnoDB: The dict_boot() function did not set the maximum length of columns used for index
fields, resulting in dict_index_node_ptr_max_size() returning incorrect values. (Bug
#19791849)
• InnoDB: When dummy tables are created, the autoinc_mutex member of the of the
dict_table_t object was created unnecessarily. Similarly, the zip_pad.mutex object of
dict_index_t object was created unnecessarily for dummy indexes. To avoid unnecessary mutex
contention, autoinc_mutex and zip_pad.mutex objects are now allocated and initialized on the
first lock attempt. (Bug #19788198, Bug #73361)
• InnoDB: log_sys->mutex was not held when reading the fil_space_t::max_lsn field,
causing a race condition. (Bug #19729855)
References: This issue is a regression of: Bug #18645050.
• InnoDB: btr_insert_into_right_sibling() could delete node pointers at the parent page.
To avoid latch order violations and deadlocks with other threads, lock intention is now checked for
leaf pages as well as upper non-leaf pages. (Bug #19729316)
• InnoDB: InnoDB performed unnecessary table lookups in the change buffer during tablespace
export operations. (Bug #19724300)
• InnoDB: The fil_tablespace_deleted_or_being_deleted_in_mem() function, added in
MySQL 4.1, was longer necessary and has been removed. There is a fallback check in fil_io()
that returns DB_TABLESPACE_DELETED. (Bug #19719727)
• InnoDB: To ease future development, the ha_innobase::create function was refactored. (Bug
#19718568)
164
MySQL 5.7 Release Notes
• InnoDB: Redundant conditional branching and a redundant a check for srv_read_only_mode
were removed from ha_innobase::create(). Redundant conditional branching and an unused
local variable were removed from ha_innobase::delete_table(). (Bug #19712822)
• InnoDB: Unused code related to UTF-8 handling for InnoDB FULLTEXT indexes was removed. (Bug
#19712059)
• InnoDB: The fil_index_tree_is_freed() function, which returned a false negative when
the index root page was reallocated, was replaced by improved logic for freeing index trees. This
patch also removed a redundant parameter that was passed to dict_drop_index_tree(). (Bug
#19710798)
• InnoDB: The InnoDB change buffer tree, which was created inside the InnoDB data dictionary
cache unnecessarily, is now created directly, bypassing the cache. This patch also removes the
DICT_UNIVERSAL flag, which was set in in connection with DICT_IBUF. Neither of the flags is used
for persistent data structures, which makes DICT_UNIVERSAL unnecessary. (Bug #19710650)
• InnoDB: The fil_space_t::tablespace_version field, introduced to keep track of ALTER
TABLE...DISCARD TABLESPACE followed by ALTER TABLE IMPORT TABLESPACE operations,
was removed. The tablespace_version field ensured that a change buffer merge would not
occur for old buffered entries while a tablespace with the same space_id was imported. The field
was redundant and no longer required. (Bug #19710564)
• InnoDB: Removed unused code related to index name lookup, and replaced a function that
permitted duplicate index names. (Bug #19710348)
• InnoDB: Column and index names were unnecessarily escaped in InnoDB diagnostic messages
and interfaces. This patch also adds a new function, innobase_quote_identifier, for quoting
FOREIGN KEY constraints and column names in SHOW CREATE TABLE output. (Bug #19704286)
• InnoDB: When using the MySQL thread pool, connections encountered long semaphore waits
during load testing. (Bug #19703758, Bug #19887285)
• InnoDB: Since the introduction of fast index creation in MySQL 5.1, index objects have been added
to the SYS_INDEXES internal data dictionary table before being committed. Uncommitted entries
were identified by a prefix (defined as TEMP_INDEX_PREFIX). TEMP_INDEX_PREFIX was also
used in the InnoDB data dictionary cache, resulting in complications when displaying or comparing
index names. To address this problem, a new dict_index_t::uncommitted flag was introduced
along with accessor methods is_committed() and set_committed(). Before this change,
some InnoDB INFORMATION_SCHEMA tables displayed uncommitted index names with a preceding
question mark. The question mark prefix is now omitted. (Bug #19702328)
• InnoDB: InnoDB displayed tables names inconsistently in diagnostic messages. Some messages
displayed table names using an internal representation while other messages displayed table names
in a translated form. (Bug #19694618)
• InnoDB: For FULLTEXT indexes, a lookup for the FTS_DOC_ID_INDEX was performed during DML
operations. To avoid the costly lookups, a pointer to FTS_DOC_ID_INDEX is now cached at DDL
time. (Bug #19693488)
• InnoDB: To simplify code, the is_redo_skipped flag, introduced in MySQL 5.7.5 with the CREATE
INDEX bulk load feature, was removed. The flag caused redo logging for page allocation to be
skipped. Redo logs are now generated for page allocation, even when creating a new tablespace.
(Bug #19693192)
• InnoDB: An MLOG_FILE_NAME redo log record, which provides the information necessary to
identify tablespace files that changed since the last checkpoint, were emitted on log checkpoint even
though there were no changes to tablespace files. If a tablespace file is missing or unreadable on
crash recovery, the inconsistency should be ignored if there are no redo logs to apply. For related
information, see Tablespace Discovery During Crash Recovery. (Bug #19685095)
165
MySQL 5.7 Release Notes
• InnoDB: An unused parameter, archive_space_id, that was passed and ignored in the
log_group_init function, was removed. (Bug #19669129)
References: See also: Bug #16296837.
• InnoDB: In read-only mode, a GIS data search using the MBRCONTAINS() function raised an
assertion. (Bug #19664678)
• InnoDB: Page reservation for the index tree was not performed before calling btr_page_alloc().
(Bug #19660261)
• InnoDB: Building MySQL 5.7.5 on a Debian 7 32-bit system with GCC resulted in a MySQL server
failure. The problem was due to a GCC bug (Debian Bug Report #764220) that causes incorrect
code to be emitted when a function that takes a pointer or reference as a parameter is declared
as attribute((const)) or attribute((pure)). The problem is known to occur on Debian
Wheezy 7.6 x86 with g++-4.6 (Debian 4.6.3-14) 4.6.3 or g++ (Debian 4.7.2-5) 4.7.2, and on Debian
Jessie/Sid amd64 with gcc (Debian 4.9.1-15) 4.9.1 or g++ (Debian 4.9.1-15) 4.9.1. The bug may
exist in other gcc-4.x versions as well any GCC version that accepts the attribute((const)) or
attribute((pure)) code.
To avoid the bug, problematic attributes have been removed from MySQL functions that take
pointers or references that they are dereferencing.
This patch also removed instances of attribute((nonnull)), which do not always generate
a warning when NULL is passed, and may not emit code for handling the NULL case. (Bug
#19632776)
• InnoDB: A rollback operation raised an assertion in
lock_rec_free_all_from_discard_page_low() due to stale records locks on empty pages
that were being removed from an index tree. (Bug #19628598)
• InnoDB: The modify_clock value is now stored to allow the buf_page_optimistic_get()
function, used to get optimistic access to a database page, to succeed in most cases. An
unnecessary PAGE_HEAP_TOP (record heap top pointer) and FIL_PAGE_TYPE (file page type) set
was removed from btr0bulk.cc. (Bug #19611367)
• InnoDB: The dict_set_corrupted() function attempted to update the clustered index of the
SYS_INDEXES data dictionary table incorrectly. (Bug #19584379)
• InnoDB: Compiling with the new Clang 3.5 release resulted in a number of InnoDB compilation
warnings. (Bug #19579603)
• InnoDB: Removed unused API definitions from api0api.h and api0api.cc source files. (Bug
#19579149)
• InnoDB: The DICT_TF2_USE_FILE_PER_TABLE flag should be tested by the
dict_table_use_file_per_table function to verify that the table uses a file-per-table
tablespace. (Bug #19578222)
• InnoDB: With innodb_create_intrinsic enabled, temporary tables created during ALTER
TABLE operations were marked as optimized temporary tables, resulting in an assertion. Enabling
innodb_create_intrinsic should only affect CREATE TABLE and CREATE INDEX operations.
(Bug #19565749)
• InnoDB: Valgrind testing returned a Conditional jump or move depends on
uninitialised value(s) at buf_page_is_zeroes error. The unread portion of the page
contained garbage values. (Bug #19536534)
• InnoDB: An INSERT operation on a spatial index resulted in a crash in split_rtree_node().
The mbr_join_square function failed to check for infinity and NaN (not a number) values. (Bug
#19533996, Bug #73776)
166
MySQL 5.7 Release Notes
• InnoDB: With change buffering enabled, a buffered sequence of operations that should not have
been buffered resulted in an Unable to purge a record error. (Bug #19528825, Bug #73767)
• InnoDB: Pages with a checksum value of zero were incorrectly treated as empty pages. A page
should only be considered empty if its checksum value and LSN field values are zero. (Bug
#19500258, Bug #73689)
References: This issue is a regression of: Bug #17335427.
• InnoDB: The C-style function, ib_logf(), used for writing log messages, has been removed in
favor of C++ style classes (ib::info, ib::warn, ib::error, and ib::fatal). (Bug #19495721)
• InnoDB: The InnoDB data dictionary was not updated when a ALTER TABLE ... CHANGE
COLUMN operation changed the case of the column name. (Bug #19465984)
• InnoDB: InnoDB returned a table not found error for a missing tablespace file. (Bug
#19419026)
• InnoDB: InnoDB shutdown stalled due to a user thread that was in a waiting state. (Bug
#19386426)
• InnoDB: After upgrading to MySQL 5.7, an ALTER TABLE operation on a tables created in MySQL
5.6 and containing GIS data would cause a serious error. (Bug #19368904)
• InnoDB: After an online ALTER TABLE ... ADD INDEX operation, crash recovery failed due to a
regression introduced with the CREATE INDEX bulk insert enhancement introduced in MySQL 5.7.5.
(Bug #19316315, Bug #19308426)
• InnoDB: On non-Windows platforms, os-file_pread and os_file_pwrite functions return -1
when an error occurs. This value was printed in an error message as the number of bytes read or
written. Instead of printing the -1 value in the error message, a separate error message indicating
a system call failure is now printed. Thanks to David Bennett for the patch. (Bug #19315210, Bug
#73365)
• InnoDB: A memory access violation caused fts_optimize_thread and mysqld to terminate.
(Bug #19314480)
• InnoDB: A procedure, called from a function to perform an operation on a temporary table, caused
the server to halt. (Bug #19306524)
• InnoDB: Attempting to shut down the server after starting the server with
innodb_force_recovery=6 resulted in a hang. (Bug #19265668, Bug #73341)
• InnoDB: The fil_inc_pending_ops() and fil_decr_pending_ops() functions
have been replaced by fil_space_acquire() and fil_space_release().
This change removes a space ID lookup. The new functions are implemented
in buf_load(), fsp_get_available_space_in_free_extents(), and
lock_rec_block_validate(), which is a debug function. The patch for this bug also removed
fil_tablespace_is_being_deleted(), which was an orphaned function. (Bug #19149177)
• InnoDB: If the log sequence number (LSN) has not increased, the log_write_up_to() function
should not initiate redo log writing. (Bug #19068569, Bug #73109)
• InnoDB: A CREATE TABLE operation failed with a table is full error when running a MySQL
server with innodb_flush_method=O_DIRECT on a Linux system with an ext3 file system. The
error was due to an internal posix_fallocate() failure that occurs when O_DIRECT is specified.
To allow the file operation to proceed, the internal posix_fallocate() failure now prints an error
message to the error log. (Bug #18903979)
• InnoDB: As part of a cleanup of InnoDB INSERT code paths, assertion code was added to
ha_innobase::end_stmt() and other places at the start of DDL. Debug code was added to
row_log_table_apply(). Assertion code was added to optimized temporary table-related
functions, and unused parameters were removed. (Bug #18894337)
167
MySQL 5.7 Release Notes
References: This issue is a regression of: Bug #11758237.
• InnoDB: A full-text search operation caused a segmentation fault. (Bug #18778259)
• InnoDB: Enhancements introduced in MySQL 5.7.5 related to tablespace discovery during crash
recovery caused a performance regression. (Bug #18645050)
• InnoDB: If a database is named using uppercase letters on a MySQL server with
lower_case_table_names=2 (which is default on OS X), InnoDB stores the database name as
specified in the InnoDB internal system table (SYS_TABLES) but stores the name in lowercase on
disk. During crash recovery, the case mismatch resulted in a conflict that marked the tablespace
.ibd file as missing. The patch for this bug converts database names to lowercase on crash
recovery. (Bug #18412598, Bug #72043)
• InnoDB: A full-text query expansion search using a search phrase plus wildcard operator resulted in
InnoDB: Did not find word ... for query expansion search errors. This patch also
addressed an issue related to full-text indexes being “unsynced” by DDL rollback. (Bug #18229097,
Bug #19831736)
References: This issue is a regression of: Bug #17373659.
• InnoDB: In debug builds, the InnoDB Lock Monitor asserted after a DROP TABLE operation, and the
InnoDB Monitor encountered an assertion in buf_page_get_gen. (Bug #18062698, Bug #71343,
Bug #18173184, Bug #68116)
• InnoDB: A CREATE TABLE operation that failed when innodb_strict_mode was enabled
succeeded without printing a warning when innodb_strict_mode was disabled. (Bug #17852083)
• InnoDB: buf_LRU_free_page() would call buf_page_set_sticky(bpage), needlessly
making removed pages sticky in some cases. (Bug #17407091, Bug #70228)
• InnoDB: A slow shutdown (innodb_fast_shutdown=0) after crash recovery raised an assertion.
Slow shutdown did not wait for background rollback operations to finish before proceeding. (Bug
#16862810)
• InnoDB: The criteria used to define a small tablespace was inconsistent. Thanks to Laurynas
Biveinis for the patch. (Bug #16696906, Bug #68970)
• InnoDB: For explicit cache coherency, a write barrier was added to the head of
os_thread_create_func(), and a read barrier was added to assertion code in
rw_lock_free_func(). (Bug #13364876, Bug #62692, Bug #18870970, Bug #72809)
• InnoDB: A memcached append operation on an INT column caused a segmentation fault. append
operations on INT columns are not supported and are now blocked. (Bug #75200, Bug #20209756)
• InnoDB: The integer column value was handled incorrectly for the memcached incr and decr
commands. (Bug #69415, Bug #20083106, Bug #74874, Bug #20044123)
• Partitioning: When multiple columns are used in KEY partitioning, their order may help determine
the partition in which the row is placed. Changing this order by means of an ALTER TABLE that
uses ALGORITHM=INPLACE can lead to inconsistency when placing rows in partitions; in other
words, a row inserted before such an operation is placed in one partition, but the same row inserted
afterwards is placed in a different one. For this reason, altering the order of a multicolumn index
online is no longer allowed when that index is also used as the base for partitioning the table by KEY;
instead, you must use a copying ALTER TABLE to perform the change. (Bug #17896265)
• Replication: When enforce_gtid_consistency was set to WARN, if a second GTID consistency
violating statement within a transaction was encountered, it was not raising a warning. This was
due to the fact that by design the transaction context was marked as GTID violating, hence no other
warnings were being issued until the transaction committed. The fix ensures that a warning is raised
for all statements inside a transaction correctly. (Bug #20414559)
168
MySQL 5.7 Release Notes
• Replication: After restarting a slave, the first relay log was missing the Previous_gtids log event.
Since MySQL version 5.7.6, a Previous_gtids log event is added to every log. This fix ensures
that a Previous_gtids log event is correctly added to the first relay log. (Bug #20106390)
• Replication: When purging binary logs and the first left binary log contained only a
Previous_gtids log event, a lost_gtids->is_empty() assertion was caused. This was
related to the fix for Bug#16741603 and has now been corrected. (Bug #20075721)
• Replication: When using a slave configured to use a special character set such as UTF-16, UTF-32,
or UCS-2, the receiver (I/O) thread failed to connect. The fix ensures that in such a situation, if
a slave's character set is not supported then default to using the latin1 character set. (Bug
#19855907)
• Replication: If a client thread on a slave executed FLUSH TABLES WITH READ LOCK while the
master executed a DML, executing SHOW SLAVE STATUS in the same client became blocked,
causing a deadlock. The fix ensures that the read lock is only held during the period that the relay log
is being updated and the deadlock is avoided. (Bug #19843808)
• Replication: When using multi-source replication with multiple channels and with a multi-threaded
slave enabled, resetting the slave and then executing RESET SLAVE ALL, START SLAVE or STOP
SLAVE resulted in a crash. This has now been fixed and the multi-threaded slave can be restarted in
a multi-source replication setup. (Bug #19784641)
• Replication: The CHANGE REPLICATION FILTER statement can be used to create an empty filter,
for example when clearing previously configured replication filters. This caused a crash in previous
versions when creating an empty filter for REPLICATE_DO_TABLE, REPLICATE_IGNORE_TABLE,
REPLICATE_WILD_DO_TABLE, or REPLICATE_WILD_IGNORE_TABLE. This fix ensures that these
replication filters can be safely cleared by setting the filter to be empty. (Bug #19711674)
• Replication: When using a MySQL version that had been compiled with the WITH_DEBUG option
enabled, using expire_logs_days to purge binary logs caused a restart to crash the server.
This problem arose after the fix for Bug #17283409. The fix ensures that current_thd is checked
before calling DEBUG_SYNC(). (Bug #19553099)
• Replication: When using a multi-threaded slave, the slave receiver (SQL) thread stopped with
an ER_MTS_CANT_PARALLEL error when issuing a LOAD DATA INFILE statement that tried to
load data into a non-transactional table on the master but failed, for example due to a primary key
violation. This was caused by the multi-threaded slave applier incorrectly handling DELETE_FILE
events. The fix ensures that a multi-threaded slave handles DELETE_FILE events correctly. (Bug
#19552923)
• Replication: Sometimes the slave I/O thread leaves a partial group in the current relay log, for
example when it is killed or stopped. After it is restarted, a new relay log is created on rotation
and a pair of ROTATE_EVENT and FORMAT_DESCRIPTION_EVENT is replicated from master and
written into the new relay log. When using a multi-threaded slave, problems such as error 1755 were
encountered when applying the remaining part of the group in the relay log. This fix ensures that if
MASTER_AUTO_POSITION is enabled, then the worker rolls back the partial group, finishes its work,
and then applies the new complete copy of the group. If MASTER_AUTO_POSITION is disabled, the
worker does not roll back the partial group. (Bug #19545298)
• Replication: Start log events were not checked by slaves for minimum size. (Bug #19145698)
• Replication: When using row-based replication with slave_type_conversions enabled, a
binary log with more than one Rows_log_event in succession caused a crash. This was due to the
temporary tables generated as part of the slave_type_conversions process being released too
early. This fix ensures that the temporary tables are not released too early, and also ensures that
long transactions do not cause an out of memory error. (Bug #18770469, Bug #19704825)
• Replication: When using binary log files that had been manually copied from the master, for
example to avoid I/O thread reading delay, a multi-threaded slave generated error 1755. Because
the Previous_gtids log event is logged using the master's server_id and not the slave's
169
MySQL 5.7 Release Notes
server_id, the previous events were not being skipped correctly. This fix ensures that the events
in Previous_gtids log event are always skipped, regardless of whether they are from the relay log
(generated on the slave) or from the binary log (generated on the master and manually copied to the
slave as the relay log). (Bug #17812024)
• Replication: When replicating from an earlier version MySQL master, such as version 4.1,
checksums are not used for events. Replicating to a slave running a newer version of MySQL, such
as version 5.6, which has slave_sql_verify_checksum enabled by default meant that the last 4
bytes of events from the older master were being incorrectly interpreted as the checksum. A warning
is now generated and to avoid such a situation, set slave_sql_verify_checksum=0 to disable
checksums on the slave. (Bug #17276183)
• Replication: When using multi-source replication and a multi-threaded slave in a situation
that required recovery of a channel, such as after a slave applier thread error, or after a crash,
the channel was not being recovered correctly. This meant there was no attempt to fix gaps in
transaction execution left by the stopped session, which led to some transactions being applied
repeatedly. The fix ensures that in such a situation, the correct channel is passed through to multithreaded slave recovery. (Bug #74906, Bug #20046222)
• Replication: Ignorable log events were introduced in MySQL 5.6, but were found to not be
functioning correctly. This has now been fixed. (Bug #74683, Bug #19949915)
• Replication: When an XA transaction was active, executing an internal rollback, for example using
the BINLOG statement, resulted in an assertion. The fix ensures that a rollback happens only for
a slave when a transaction spans multiple binary log files. Rollback does not happen now if the
Format_description comes from the BINLOG statement being executed in the MySQL client. (Bug
#74597, Bug #19928622)
• Replication: The GTIDs of transactions committed in a group were not added to gtid_executed in
order and this sometimes caused temporary gaps in gtid_executed. When these gaps occurred,
the server would have to add and remove intervals from the GTID set, and this requires a mutex,
which would cause contention and could reduce performance. The fix ensures that GTIDs are added
to gtid_executed in the same commit order without gaps. (Bug #74328, Bug #19982543)
• Replication: When gtid_mode=ON and log-bin=OFF, committed transaction GTIDs are added to
the mysql.gtid_executed table. In such a configuration, the committed transaction GTID was not
being correctly added to gtid_purged until the next time the server was restarted. The fix ensures
that committed transaction's GTIDs are added to gtid_purged at the time of commit. (Bug #74279,
Bug #19781336)
• Replication: In a replication topology where:
• the slave had GTID_MODE=ON and MASTER_AUTO_POSITION=1
• the master had GTID_MODE=ON and had not executed any transactions since it was started
if the slave used the MASTER_POS_WAIT function to wait until it had received the full binary log
from the master while the master had not executed any transactions, then the MASTER_POS_WAIT
function would never finish, or would time out. This was caused because after a server restart, the
master's binary log ends with a Previous_gtids log event but this event was not being replicated,
so the slave was not made aware of the master's binary log position. The fix ensures that the
Previous_gtids log event is replicated correctly, so that the slave becomes aware of the correct
binary log position on the master, ensuring that the MASTER_POS_WAIT function can finish. (Bug
#73727, Bug #19507923)
• Replication: When restarting MySQL with relay_log_recovery enabled to recover from a crash,
if the SQL thread had never been started, the position from which to start recovery was not correctly
initialized because Relay_Master_Log_File was missing. This fix ensures that in such a situation
each of the relay logs, starting from the first relay log file, is searched for a rotate event from the
master, which specifies where replication started from. This rotate event is then used to set the SQL
170
MySQL 5.7 Release Notes
thread's Relay_Master_Log_File and Relay_Log_Pos and recovery continues as normal. (Bug
#73039, Bug #19021091)
• Replication: When using GTIDs for replication and with MASTER_AUTO_POSITION enabled, if a
slave requested GTIDs which had been already been purged by the master, the master was sending
all available GTIDs. This happened because the master reads all available binary logs and searches
for a binary log which contains a GTID that is not contained in the union of gtid_executed and
gtid_retrieved. If such a GTID is found, the master starts sending the information starting from
that location. In a situation where the union of the slave's gtid_executed and gtid_retreived
set did not contain the master's gtid_purged set, the slave would expect GTIDs which had already
been purged by the master. This fix ensures that in such a situation, the slave's I/O thread is aborted
with an error "Master has purged binary logs containing GTIDs that the slave requires.". (Bug
#73032, Bug #19012085)
• Replication: When using a multi-threaded slave with GTID based replication, enabling -replicate-same-server-id caused the slave thread to stop with an error and replication could
not be started. This was caused by a Previous_gtids log event not being correctly filtered in
such a setup and reaching the worker thread. The fix ensures that Previous_gtids log event is
correctly processed by the coordinator thread. (Bug #72988, Bug #18967791)
• Replication: A kernel mutex contention was being caused because mysqlbinlog was calling
localtime() for every event read, which in turn called stat(/etc/localtime). This fix ensures that
mysqlbinlog uses localtime_r(), which is optimized to store the read only timezone internal
structure. This also means that mysqlbinlog now establishes the time zone at the beginning of
processing and you can not change it during processing. This is the same behavior as MySQL
server. (Bug #72701, Bug #18808072)
• Replication: In normal usage, it is not possible for a slave to have more GTIDs than the master.
But in certain situations, such as after a hardware failure or incorrectly cleared gtid_purged, the
master's binary log could be truncated. This fix ensures that in such a situation, the master now
detects that the slave has transactions with GTIDs which are not on the master. An error is now
generated on the slave and the I/O thread is stopped with an error. The master's dump thread is also
stopped. This prevents data inconsistencies during replication. (Bug #72635, Bug #18789758)
• Replication: When using a GTID based replication slave with auto positioning enabled, there was
a possibility that the last fully received transaction could be requested again by the slave I/O thread
when the GTID of the transaction was not in the slave's gtid_executed set. This situation could
occur for example if the SQL thread had not applied the transaction or a RESET MASTER statement
was issued on the slave to clean up its gtid_executed set. The fix ensures that a GTID based
replication slave using auto positioning does not ask for a fully received transaction twice, regardless
of the slave's gtid_executed set, and it now only adds a GTID to the Retrieved_Gtid_Set
when the whole transaction has been received. (Bug #72392, Bug #18629623, Bug #17943188)
• Replication: When using SHOW SLAVE STATUS to monitor replication performance,
Seconds_Behind_Master sometimes displayed unexpected lag behind the master. This was
caused by Previous_gtids log events being written to the slave's relay log with a timestamp
behind the master, and then being used to calculate the Seconds_Behind_Master. This fix
ensures that events generated on the slave that are added to the relay log and are not used when
calculating Seconds_Behind_Master. (Bug #72376, Bug #18622657)
• Microsoft Windows: On Windows, the replace utility did not work. (Bug #16581605)
• Solaris: Binary distributions for Solaris built with Sun Studio now ship with the stlport library due
to a dependency of client programs on that library. (Bug #19845068)
• Solaris: For 32-bit Solaris builds, alignment problems resulting from improper use of varargs function
arguments caused core dumps and incorrect output. (Bug #74395, Bug #19821617)
• For debug builds, an assertion could be raised during index selection if a spatial index used a column
that was also part of the primary index. (Bug #20451454)
171
MySQL 5.7 Release Notes
• On Linux, trying to install a .dll plugin (intended for Windows) resulted in a memory leak. (Bug
#20439894)
• On 32-bit platforms, byte-count calculations for utf8 arguments for RPAD() could overflow and
cause a server exit. (Bug #20316028)
• mysqltest had a memory leak if another process shut down the server. (Bug #20221262)
• The mysql_session_track_get_first() C API function returned 1 instead of 0 even after a
valid query was executed to change the session state. (Bug #20126551)
• On Ubuntu 14.10, MySQL install operations could fail to reload AppArmor. (Bug #20092641)
• For debug builds, the server could raise an assertion during DELETE processing due to failure to
handle a subquery that was required to be a scalar subquery but returned more than 1 row. (Bug
#20086791)
• mysql_list_fields() and mysql_stmt_prepare() could leak memory. This problem was
introduced in MySQL 5.7.5 as a result of the change to EOF packet handling. (Bug #20065461, Bug
#20065517)
• Some queries with argumentless functions, GROUP BY, and WITH ROLLUP caused an assertion to
be raised. (Bug #20034943)
• A user with a name of event_scheduler could view the Event Scheduler process list without the
PROCESS privilege. (Bug #20007583, Bug #20754369)
• The mysql client could exit prematurely when invoked with the --xml option. (Bug #19974879)
• InnoDB table checksum calculation could yield an incorrect result if the value of the
innodb_checksum_algorithm system variable was modified during the operation. (Bug
#19931177)
• The LIKE operator could produce unreliable results of the ESCAPE clause contained an expression
that was constant at execution time but unknown prior to that. (Bug #19931126)
• Execution of certain BINLOG statements while temporary tables were open by HANDLER statements
could cause a server exit. (Bug #19894987, Bug #20449914)
• A malformed mysql.proc table row could result in a server exit for DROP DATABASE of the
database associated with the proc row. (Bug #19875331)
• SHOW GRANTS after connecting using a proxy user could display the password hash of the proxied
user. (Bug #19817663)
• For debug builds, the optimizer could produce a bad index scan cost when creating a temporary
table for a derived table, and raise an assertion as a result. (Bug #19793998)
• Unlocking a temporary table after locking and truncating it could cause a server exit. (Bug
#19786309)
• IN predicates could be incorrectly flagged as candidates for semi-join flattening, causing an
assertion to be raised when flattening was attempted. (Bug #19779600, Bug #18932813)
• Large values of the transaction_prealloc_size system variable could cause the server to
allocate excessive amounts of memory. The maximum value has been adjusted down to 128K. A
similar change was made for transaction_alloc_block_size. Transactions can still allocate
more than 128K if necessary; this change reduces the amount that can be preallocated, as well as
the maximum size of the incremental allocation blocks. (Bug #19770858, Bug #20730053)
• RPM and DEB packages set the default sql_mode value incorrectly (they did not set
ONLY_FULL_GROUP_BY, which is now included in the default value). (Bug #19766800)
172
MySQL 5.7 Release Notes
• Source RPM packages were missing the proper dependency on the Boost library. (Bug #19714453)
• A server exit could occur for queries that compared two rows using the <=> operator and the rows
belonged to different character sets. (Bug #19699237, Bug #20730155)
• The Enterprise Encryption plugin could mishandle string arguments. (Bug #19688008, Bug
#20730103)
• The optimizer detected functional dependency for equality expressions of the form col_name =
expr, but not for expressions of the form (col_name, ...) = (col_name, ...). Now it
handles the latter as well. (Bug #19687724)
• Certain InnoDB errors caused stored function and trigger condition handlers to be ignored. (Bug
#19683834, Bug #20094067)
• On some 32-bit platforms, GET_LOCK(lock_name, -1) returned immediately due to timeout rather
than waiting for the lock. (Bug #19674349)
• If a DML statement containing a subquery caused a deadlock inside InnoDB, InnoDB would roll
back the transaction. This would not be noticed in the SQL layer, with the result that execution
continued, eventually leading to an assertion being raised inside InnoDB. (Bug #19670163)
• With default_authentication_plugin set to sha256_password, password hashes written to
the binary log were in the wrong format. (Bug #19660998)
• GROUP BY or ORDER BY on a CHAR(0) NOT NULL column could lead to a server exit. (Bug
#19660891)
• Under load, the server could exit while attempting to populate the OBJECT_TYPE column for selects
from the events_waits_current Performance Schema table. (Bug #19658933)
• ST_AsGeoJson() could fail when given an illegal max_dec_digits or options argument. (Bug
#19657747)
• Geohash spatial functions failed when given a geohash argument having a collation other than the
default collation. (Bug #19657725)
• Checks enforced by ONLY_FULL_GROUP_BY cannot reliably be run if a grouped query is part of
CREATE VIEW. The MySQL server tried to run those checks and could exit; now only statements
that actually use the view run the checks. (Bug #19636980)
• For debug builds, an assertion could be incorrectly raised when a grouped query referred to a view.
(Bug #19636409)
• For debug builds: Adding a unique index to a POINT NOT NULL column triggered a warning and the
key was not promoted to a primary key. Creating a unique index on a different non-NULL column in
the same table then raised an assertion. (Bug #19635706, Bug #24469860)
• When there is no change in session state, the OK packet sent from server to the client contained an
unneeded byte at the end of the packet. (Bug #19625718)
• Debug builds of mysql_install_db did not compile on Solaris 11 U2 due to use of the deprecated
vfork() function. (Bug #19603400)
• An assertion could be raised for either of these conditions: 1) A conversion to semi-join intended
for scalar subqueries was applied to multiple-row subqueries. 2) An IN predicate for which the lefthand side was a scalar subquery converted to a semi-join was checked to see whether it could use
materialization. (Bug #19586047)
• For debug builds, if an intermediate or final result produced NaN or a negative number,
ST_Distance() caused a server exit. This function now produces a ER_GIS_INVALID_DATA error
instead. (Bug #19584716)
173
MySQL 5.7 Release Notes
• CMake configuration was adjusted to handle new warnings reported by Clang 3.5, using the Wpointer-bool-conversion and -Wundefined-bool-conversion compiler options. (Bug
#19584183)
• If a CREATE TABLE or ALTER TABLE partitioning statement was executed in strict SQL mode and
an ER_WRONG_TYPE_COLUMN_VALUE_ERROR error occurred, the sql_mode was reset to '' and
the stack of error handlers was corrupted, leading to a server exit. (Bug #19584181)
• Attempting to start the server on a port that was already in use produced Valgrind errors. (Bug
#19566148)
• Session state was not included with the results of queries saved in the query cache. (Bug
#19550875)
• Illegal CREATE TABLE statements could fail to create the table (as expected), but still generate table
statistics in the Performance Schema. (Bug #19535945)
• Setting session_track_system_variables to NULL could lead to an eventual server exit. (Bug
#19514067)
• The client protocol tracing plugin did not account for the removal of the EOF packet from the client/
server protocol in MySQL 5.7.5. (Bug #19512199)
• The default value for the condition filtering effect for equality conditions on nonindexed columns was
adjusted from 0.005 to 0.1. The original value caused too-high estimates for the condition filtering
effect for columns with low cardinality. (Bug #19505175)
• A UNION statement for which the first query block returned a POINT column and the second returned
a geometric column with a non-POINT value failed if the query used InnoDB temporary tables or
stored the result in an InnoDB table. (Bug #19471564)
• An assertion could be raised for queries evaluated using a semi-join LooseScan if an index scan was
used on one index and a range scan on another index. (Bug #19465034)
• For client programs, --secure-auth is now deprecated and --skip-secure=auth is illegal, but
use of --skip-secure-auth resulted in a warning followed by the help message rather than an
error. (Bug #19438612)
• In strict SQL mode, some SELECT statements could execute differently within and without stored
procedures. (Bug #19418619)
• If the audit_log plugin encountered a disk-full error, the server would exit.
Now, if the file system to which the audit log is being written fills up, a “disk full” error is written to
the error log. Audit logging continues until the audit log buffer is full. If free disk space has not been
made available by the time the buffer fills, client sessions will hang, and stopping the server at the
time of client sessions hanging will result in audit log corruption. To avoid this if client sessions are
hung, ensure that free space is available on the audit logging file system before stopping the server.
(Bug #19411485)
• With the validate_password plugin activated and dictionary lookups enabled, passing a userdefined variable to PASSWORD() could cause a server exit. (Bug #19388163)
• Statements that used Geohash spatial functions could not be prepared. (Bug #19383904)
• The XPath number() function failed when invoked with no argument. Now MySQL treats number()
as if it had been invoked for the current context node (in other words, as if number(.) had
been used instead), which is the behavior called for in the XPath specification for this case. (Bug
#19323016)
References: This issue is a regression of: Bug #19056196.
174
MySQL 5.7 Release Notes
• With the query cache enabled, certain queries that began with comment sequences could cause
invalid memory read errors. (Bug #19322795)
• Certain GRANT PROXY statements affected only in-memory privileges and were reverted by FLUSH
PRIVILEGES or a server restart. (Bug #19309652)
• STR_TO_DATE() could mishandle conversion of numeric input to date, resulting in a server exit.
(Bug #19047644)
• Fixed a Valgrind warning for an out-of-bounds read while parsing '0E+'. (Bug #19047527)
• Under certain conditions, DATE_FORMAT() could use the same buffer for its format argument and
the function result, resulting in invalid memory reads. (Bug #19047488)
• Conversion of a string to an IPv6 address could raise a Valgrind warning. (Bug #19047425)
• For failure to create a temporary table due to being out of file descriptors, the server exited rather
than returning an error. (Bug #18948649)
• mysqldump failed to report a disk-full error if the dump destination was located on an NFS mount.
(Bug #18817867)
• Under certain conditions, a proxy user could expire the password of the proxied user. (Bug
#18815349)
• Previously, InnoDB permitted a foreign key to be created which referenced a parent table for which
the user did not have sufficient privileges. Now, the user must have the REFERENCES privileges for
the parent table to create a foreign key. (Bug #18790730)
• The server could exit due to an optimizer failure to allocate enough memory for resolving outer
references. (Bug #18782905, Bug #19892803)
• The mysql_session_track_get_first() and mysql_session_track_get_next() C API
functions could cause a client crash if passed invalid arguments. (Bug #18769620)
• If two internal temporary tables were created based on the same aggregate function, the server
could exit. (Bug #18766378)
• For some queries that contained a derived table (subquery in the FROM clause), delay of
materialization resulted in a suboptimal execution plan due to a less accurate row-count estimate.
(Bug #18607971)
• For some multiple-table UPDATE statements, the join order of the tables could incorrectly influence
the result. (Bug #18449085)
• ST_Touches() could cause a server exit for some inputs. (Bug #18304448)
• Copying InnoDB tables containing full-text columns from Windows to Linux caused a server exit on
Linux during full-text index initialization. (Bug #18285007, Bug #19864963, Bug #73155)
• A server running with --default-authentication-plugin=sha256_password rejected
connection attempts by MySQL 5.1 clients requiring a password. (Bug #18160400)
• The validate_password plugin did not properly enforce password constraints for accounts
authenticated by the sha256_password authentication plugin. (Bug #18140348)
• For UPDATE and DELETE statements, the server could exit after attempting to access an uninitialized
data structure. (Bug #18036143)
• Execution of a prepared statement with a nested IN subquery and a view could cause a server exit.
(Bug #17973601)
• Starting the server with start service or mysqld_safe could result in failure to use the correct
plugin directory. (Bug #17619241)
175
MySQL 5.7 Release Notes
• FLUSH TABLES on a FEDERATED table failed if the table had been idle longer than the
wait_timeout time plus the TCP keepalive time. (Bug #17599258)
• For FEDERATED tables, IGNORE handling for DELETE IGNORE statements was ignored. (Bug
#17564775)
• For debug builds, an assertion was raised for ALTER TABLE when accessing an indexed column for
which the operation modified the column length, if the length was 767 and was being increased. (Bug
#16886196)
• Selecting all columns from INFORMATION_SCHEMA.TABLES did not reopen tables if they were in the
table cache, but selecting a subset of those columns under the same conditions did reopen tables.
(Bug #16869534)
• Creating a FEDERATED table with an AUTO_INCREMENT column using a LIKE clause results in a
server exit. (Bug #12671631)
• For debug builds, a missing error check permitted certain ALTER TABLE statements that should fail
to continue processing. (Bug #76515, Bug #20788817)
• For RPM-based installation operations, no information was produced to indicate that
mysql_install_db wrote the initial root password to $HOME/.mysql_secret. These
operations now use mysqld --initialize, which writes the password to the standard error
output. (Bug #75859, Bug #20518217)
• For some full-text queries, incomplete optimizer cleanup regarding index use could affect subsequent
queries against the same table. (Bug #75688, Bug #20442572, Bug #20261601)
• For JSON-format EXPLAIN output, the filtered value was displayed to an unwarranted number of
digits precsion. This value is now limited to two digits following the decimal point. (Bug #75663, Bug
#20429156)
• Pushed joins were not working for NDB tables. (Bug #75256, Bug #20234994)
• For a slow network connection, the timeout for downloading Boost (600 seconds) could be too short.
A new CMake option, DOWNLOAD_BOOST_TIMEOUT, is now available to configure the timeout. (Bug
#75238, Bug #20223893)
• For some queries with LIMIT, EXPLAIN could indicate that execution would be done using
filesort, but execution actually was done using an index read. (Bug #75233, Bug #20219846)
• Several spelling errors in error messages and the source code were corrected. Thanks to Otto
Kekäläinen for the patch. (Bug #75084, Bug #20135835)
• A bulk INSERT followed by other statements followed by LOAD DATA could produce incorrect
AUTO_INCREMENT values. (Bug #75068, Bug #20126635)
• When CMake did not find the required version of Boost, the error message did not indicate the
required version. Now it does. (Bug #75026, Bug #20108908)
• Enabling the log_timestamps system variable incorrectly required binary logging to be enabled.
(Bug #75025, Bug #20108866)
• During token processing, the parser check whether a token contained 7-bit data could be applied to
the wrong token. (Bug #74984, Bug #20086997)
• For a privilege error on a table underlying a view, a more general error should be supplied for
attempts to access the view, so as not to provide information about the view contents. This did not
happen in strict SQL mode. (Bug #74868, Bug #20032855)
• For subqueries that used GET_LOCK() or RELEASE_LOCK() in decimal context, the server could
create ill-defined temporary tables, resulting in a raised assertion. (Bug #74859, Bug #20031761)
176
MySQL 5.7 Release Notes
• default_password_lifetime was marked volatile, unnecessarily because it is protected
with a mutex. Thanks to Stewart Smith for the patch. (Bug #74849, Bug #20029439)
• Removed the unused grant_option global variable from mysqld.cc. Thanks to Stewart Smith for
the patch. (Bug #74847, Bug #20029398)
• InnoDB boolean full-text searches incorrectly handled + combined with parentheses; for example,
+word1 +(>word2 <word3). (Bug #74845, Bug #20028323)
• NULL as an expression was not recognized as a literal for calculation of Performance Schema
statement digests. (Bug #74813, Bug #20015246)
• MySQL failed to compile with GCC 4.9.1 in debug mode. (Bug #74710, Bug #19974500)
• An optimizer cost model constructor allocated but did not destroy a cost constant object, resulting in
a memory leak. (Bug #74590, Bug #19895764)
• Certain queries could raise an assertion when a internal string operation produced a NULL pointer
rather than an empty string. (Bug #74500, Bug #19875294, Bug #13358486, Bug #79988, Bug
#22551116)
• For mysql_install_db, the --no-defaults option was not passed to mysqld. (Bug #74477,
Bug #19863782)
• For debug builds, the server could exit due to an optimizer failure to allocate enough memory for
group references. (Bug #74447, Bug #19855522)
• For the table_io_waits_summary_by_table Performance Schema table, there was an off-byone error for the COUNT_FETCH and COUNT_READ values. (Bug #74379, Bug #19814559)
• Depending on contents, geometry collection objects were not properly destroyed, resulting in a
memory leak. (Bug #74371, Bug #19813931)
• Using (row subquery1) NOT IN (row subquery2) with NULL values in the left argument
could cause an assertion failure. (Bug #74357, Bug #19805761)
• Any index comment specified for ALTER TABLE ... ADD INDEX was ignored. (Bug #74263, Bug
#19779365)
• Reading a system variable with a NULL value inside a stored program caused any subsequent reads
to return a NULL value even though the variable value might change across invocations of the stored
program. (Bug #74244, Bug #19770958)
• Storage engine API code and functions in the handler.h and handler.cc files that are never
called or referenced were removed. (Bug #74207, Bug #19729286)
• The -DENABLED_PROFILING=0 CMake option resulted in compilation errors. (Bug #74166, Bug
#19730970)
• With the change in MySQL 5.7.5 to InnoDB for the help tables in the mysql database,
mysql_install_db became much slower for loading the help-table content. This was due to the
INSERT statements loading with autocommit enabled. Now all the statements execute as a single
transaction, not one transaction per statement. (Bug #74132, Bug #19703580)
• On CentOS 6, specifying a relative path name for the --socket option caused MySQL startup script
failure. (Bug #74111, Bug #19775856)
• The group_concat_max_len system variable could be set to its maximum value at runtime, but
not in an option file. (Bug #74037, Bug #19670915)
• The server incorrectly wrote client-side error messages to the error log: Deadlock found when trying
to get lock; try restarting transaction. (Bug #73988, Bug #19656296)
177
MySQL 5.7 Release Notes
• The client part of the sha256_password plugin could not be specified as a default client plugin
(--default-auth=sha256_password) for users authenticating with other server plugins. (Bug
#73981, Bug #19651687, Bug #17675203)
• Miscalculation of memory requirements for qsort operations could result in stack overflow errors in
situations with a large number of concurrent server connections. (Bug #73979, Bug #19678930, Bug
#23224078)
• REPEAT() wasted time concatenating empty strings. (Bug #73973, Bug #19646643)
• The capabililty of using InnoDB for temporary tables in MySQL 5.7.5 resulted in certain queries
failing: Some queries involving multiple-table UPDATE, queries involving long PRIMARY KEY
values, and queries involving DISTINCT SUM(). (Bug #73927, Bug #19627741, Bug #73932, Bug
#19628808, Bug #73702, Bug #19497209)
• On Windows, setting the max_statement_time session variable greater than 0 resulted in a
memory leak. (Bug #73897, Bug #19605472)
• In Solaris 11.2, dtrace -V output changed from Sun D to Oracle D, causing detection of DTrace
availability to fail during MySQL configuration. (Bug #73826, Bug #19586917)
• DROP DATABASE failed if the database directory contained .cfg files (such as created by FLUSH
TABLES FOR EXPORT). (Bug #73820, Bug #19573998)
• On 32-bit systems, GLength() returned a non-INF value for LineString values of infinite length.
(Bug #73811, Bug #19566186)
• mysql_config --libs_r produces output containing link flags for libmysqlclient_r, even
though that library was removed in MySQL 5.5 and replaced with a symlink to the underlying
libmysqlclient library. The output now refers directly to libmysqlclient. (The implication
is that it is no longer necessary to maintain the symlink for the sake of being able to use
mysql_config --libs_r.) (Bug #73724, Bug #19506315)
• For statement digest calculation, the Performance Schema failed to recognize signed literal numbers
as values representable by ? and created multiple digests for statements that should have had the
same signature. Now all instances of unary plus and unary minus followed by a number reduce to ?
in digests. (Bug #73504, Bug #19389709)
• Compilation on Windows using Visual Studio 2013 resulted in “unresolved external symbol” errors.
(Bug #73461, Bug #19351573)
• OLD_PASSWORD() is deprecated, but no warning was produced when it was invoked. (Bug #73376,
Bug #19285177)
• A server warning error message referred to the obsolete table_cache system variable rather than
to table_open_cache. Thanks to Daniël van Eeden for the patch to fix some of the instances.
(Bug #73373, Bug #19285052, Bug #75081, Bug #20135780)
• Certain queries for which subquery materialization or UNION DISTINCT was used together with a
hash index on a temporary table could produce incorrect results or cause a server exit. (Bug #73368,
Bug #19297190)
• If a table had a NOT NULL column, for an INSERT statement on the table for which the column value
was not specified, the server produced ERROR 1048 "Column cannot be null" rather than
Warning 1364 "Field doesn't have a default value" if there was a BEFORE trigger with
an action type different from ON INSERT. (Bug #73207, Bug #19182009)
• The IS_FREE_LOCK() and IS_USED_LOCK() function implementations contained a race condition
due to which they could access freed memory when a user lock was concurrently checked and
freed. Accessing freed memory could result in an incorrect function return value or server exit. (Bug
#73123, Bug #19070633)
178
MySQL 5.7 Release Notes
• SHOW EVENTS in the performance_schema database returned an access-denied error, rather
than an empty result as is done for INFORMATION_SCHEMA. Now an empty result is returned. (Bug
#73082, Bug #19050141)
• LOCK TABLES sometimes acquired an insufficiently strong lock for implicitly locked tables. (Bug
#72887, Bug #18913551)
• Sort order of output from a view could be incorrect when the view definition includes an ORDER BY
clause but the view is selected from using a WHERE clause. (Bug #72734, Bug #18838002, Bug
#81235, Bug #23207758)
• The server no longer logs the following warnings because they are uninformative: Client failed
to provide its character set. 'charset' will be used as client character set. (Bug #72543, Bug
#18708334)
• The ENABLED_LOCAL_INFILE CMake option incorrectly was enabled by default. (Bug #72106, Bug
#18448743)
• The server could fail to parse inserted strings for SET columns for which the column definition had
exactly 64 elements. (Bug #71259, Bug #18020499)
• Use of ODBC-format date literals could produce incorrect query results. (Bug #69233, Bug
#16812821)
• mysql_setpermission failed to properly quote user names in SQL statements that it generated.
(Bug #66317, Bug #14486004)
• For FEDERATED tables, DELETE FROM tbl_name statements were sent to the remote server as
TRUNCATE TABLE tbl_name statements, with possible side effects on transaction handling and
AUTO_INCREMENT processing. (Bug #42878, Bug #11751864)
• A file created for an internal temporary table could cause problems if the file was orphaned for some
reason and the file name was reused for later queries. (Bug #32917, Bug #11747548)
• mysql_tzinfo_to_sql failed in STRICT_ALL_TABLES SQL mode if time zone tables contained
malformed information. (Bug #20545, Bug #11745851)
Changes in MySQL 5.7.5 (2014-09-25, Milestone 15)
Note
This is a milestone release, for use at your own risk. Upgrades between
milestone releases (or from a milestone release to a GA release) are not
supported. Significant development changes take place in milestone releases
and you may encounter compatibility issues, such as data format changes that
require attention in addition to the usual procedure of running mysql_upgrade.
For example, you may find it necessary to dump your data with mysqldump
before the upgrade and reload it afterward.
• Compilation Notes
• Configuration Notes
• DTrace Support
• Error Handling
• InnoDB Notes
• Optimizer Notes
179
MySQL 5.7 Release Notes
• Performance Schema Notes
• Security Notes
• Spatial Data Support
• SQL Mode Notes
• Functionality Added or Changed
• Bugs Fixed
Compilation Notes
• Important Change; Microsoft Windows: MySQL builds on Windows using Visual Studio now
require Visual Studio 2013 or later. The previous requirement was Visual Studio 2010 or later. (Bug
#18404381)
• Important Change: The atomic-operations API was simplified to use only the existing GCC builtin implementation or platform-provided implementations (for Windows, Solaris), and to remove the
custom mutex-based fallback implementation. The retained implementations are those able to use
CPU-native atomics. This simplifies the atomics APIs and related code and deals with bugs resulting
from the fallback implementation.
As part of this work, the (undocumented) WITH_ATOMIC_LOCKS and MY_ATOMIC_MODE_RWLOCKS
CMake options were removed.
On platforms where native atomics are supported, this change introduces no issues. For other
platforms, here are potential MySQL compilation issues, and solutions:
• 32-bit Linux variants that use GCC 4.1 will no longer work. This includes Red Hat 5, which is a
supported platform. The solution to this problem is to use a new GCC or set the -march compiler
option. For example, use GCC 4.4, which is available on Red Hat 5. For information about
specifying compiler options, see Compiler Flags.
• There may be issues on unsupported platforms. For example, 64-bit PowerPC, 32-bit ARM, and
64-bit ARM will not compile with older compilers. The solution for these cases is to use GCC 4.7 or
later.
• CMake now checks for minimum versions of supported compilers: gcc 4.4 (Linux, Solaris); Sun
Studio 12u2 (Solaris client library); Clang 3.3 (OS X, FreeBSD). This check can be disabled with the
-DFORCE_UNSUPPORTED_COMPILER=ON option. (Bug #19187034)
• Noisy compiler warnings on FreeBSD 10 were silenced. (Bug #18790490)
• CMake workarounds for older OS X and XCode versions were removed. On OS X, compilation
always uses Clang, even for 32-bit builds.
Compilation on OS X is now supported for OS X 10.8 and up, using XCode 5 and up. Compilation on
older versions may work but is unsupported. (Bug #18510941)
• Previously, the MYSQL_MAINTAINER_MODE CMake option was turned on by default for debug builds
and off for release builds, and MYSQL_MAINTAINER_MODE caused -Werror to be enabled when
building with GCC. This made it cumbersome to enable -Werror under certain conditions, such as
when compiling with Clang.
Now, MYSQL_MAINTAINER_MODE is on by default when compiling debug builds with GCC, and
MYSQL_MAINTAINER_MODE enbles -Werror regardless of whether GCC or Clang is used. Enabling
-Werror with Clang can be done simply by explicitly setting -DMYSQL_MAINTAINER_MODE=1 when
running CMake. In addition, some compilation warnings reported by Clang 3.4 were fixed, making it
possible to build the default debug build with -Werror. (Bug #18313717)
• Build support was modified to produce the same warnings for Clang as for gcc. (Bug #17959689)
180
MySQL 5.7 Release Notes
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Configuration Notes
• Incompatible Change: mysql_install_db has been rewritten from Perl into C++. This enables it
to be provided as an executable binary and eliminates its dependency on having Perl installed.
The new implementation involves several other differences as well. The following items list some of
the most significant changes. For more information, see mysql_install_db — Initialize MySQL
Data Directory.
• The executable binary version is located in the bin installation directory, whereas the Perl
version was located in the scripts installation directory. For upgrades from an older version of
MySQL, you may find a version of mysql_install_db in both directories. To avoid confusion,
remove the version from the scripts directory. For fresh installations of MySQL 5.7.5 or later,
mysql_install_db is only found in the bin directory, and the scripts directory is no longer
present. Applications that expect to find mysql_install_db in the scripts directory should be
updated to look in the bin directory instead.
• Some options are handled differently. For example, the --datadir option is mandatory.
• There are several new options. For example, there are options that afford explicit control over the
administrative account that is created. By default, this is 'root'@'localhost', but you can use
--admin-user and --admin-host to change the user and host parts of the account name.
• Several options have been removed or replaced. For example, --skip-random-passwords has
been replaced by --insecure.
• mysql_install_db always overwrites the .mysql_secret file, rather than appending to it if it
exists. It is assumed that immediately after installation, you will connect to the server using the file
contents and reset the administrative password before proceeding to another deployment.
• mysql_install_db no longer passes unrecognized options to mysqld. (But you can use -defaults-extra-file to specify an option file to be added to the mysqld bootstrapping
command.)
• mysql_install_db no longer creates a default my.cnf file.
DTrace Support
• MySQL now includes DTrace support on Oracle Linux 6 or higher with UEK kernel. If DTrace is
present, server builds will detect it with no special CMake options required. For information about
using DTrace on MySQL, see Tracing mysqld Using DTrace.
Error Handling
• The server was made more consistent and resilient with regard to handling of statements for which
the IGNORE keyword is specified.
• The server failed to report warnings for INSERT IGNORE statements.
• The server could fail to report warnings for multiple-table DELETE IGNORE statements.
• UPDATE triggers for a table were invoked even for UPDATE IGNORE statements for which a unique
index caused the update to be ignored.
• For debug builds, an assertion could be raised for errors occurring in DELETE IGNORE
statements.
181
MySQL 5.7 Release Notes
• For debug builds, an assertion could be raised for deadlocks resulting from DELETE IGNORE
statements.
• For DELETE IGNORE executed on the parent table in a foreign key relationship, foreign key
violation errors were treated as warnings (correct), but rows that did not produce foreign key
violations were not deleted.
The server was made more consistent and resilient with regard to handling of statements in strict
SQL mode.
• In strict SQL mode, triggers could permit operations not permitted in strict mode.
• In strict SQL mode, deprecation warnings about duplicate indexes were incorrectly promoted to
errors.
• Strict SQL mode was not applied to multiple-table DELETE statements.
For more information about IGNORE and strict SQL mode, see Comparison of the IGNORE Keyword
and Strict SQL Mode. (Bug #6196, Bug #11744960, Bug #43895, Bug #11752648, Bug #68726, Bug
#16522924, Bug #16860715, Bug #16860829, Bug #14786621, Bug #17550423, Bug #42910, Bug
#11751889, Bug #16976939, Bug #18526888)
InnoDB Notes
• Incompatible Change: The InnoDB storage engine can no longer be disabled. The --skipinnodb option is deprecated and has no effect, and its use results in a warning. It will be removed in
a future MySQL release. This also applies to its synonyms (--innodb=OFF, --disable-innodb,
and so forth).
A new innodb_lock_no_retry flag for the --debug option is now available. -debug='d,innodb_lock_no_retry' causes InnoDB to fail immediately during startup if locks
cannot be acquired, rather than making 100 attempts before failing. This may be useful during testing
or debugging to produce faster server exit when InnoDB cannot acquire its locks.
One reason for disabling InnoDB is to enable starting a server instance using the same data
directory as an existing instance. (MyISAM permits that, but InnoDB does not.) Because InnoDB can
no longer be disabled, the workaround is to stop the existing instance before starting another so that
there is only one active instance using a data directory at a time.
• Incompatible Change: A new log record type (MLOG_FILE_NAME) is used to identify file-pertable tablespaces that have been modified since the last checkpoint. This enhancement simplifies
tablespace discovery during crash recovery and eliminates scans on the file system prior to redo log
application. For more information about the benefits of this enhancement, see Tablespace Discovery
During Crash Recovery.
This enhancement changes the redo log format, requiring that MySQL be shut down cleanly before
upgrading to or downgrading from MySQL 5.7.5.
Optimizer Notes
• The optimizer computes more accurate costs for semi-join materialization. (Bug #18558561)
• Optimizer trace output for range access in the considered_access_path section has been
improved: Instead of always printing "access_type": "ref" for index lookup types, "eq_ref",
"ref", or "fulltext" is now printed. (Bug #18195373)
• During query execution plan construction, the optimizer now uses condition filtering to make better
use of all conditions on a table in determining the estimate of qualifying rows that will be joined to
the next table. For example, even though there might be an index that can be used to select rows,
there might also be additional conditions in the WHERE clause that can further restrict the estimate for
qualifying rows.
182
MySQL 5.7 Release Notes
Use of additional conditions is controlled by the condition_fanout_filter flag of the
optimizer_switch system variable. This flag is on by default but can be disabled to suppress use
of condition filtering (for example, for a query that is found to perform better without it).
• The optimizer now uses more exact index statistics. Currently, the improved values are used by
InnoDB, with these effects:
• In many cases, better execution plans result for queries for which previously a less optimal join
index or table join order was chosen.
• The row estimates in EXPLAIN output are more accurate, as well as the filter values in some
cases.
• Cardinality estimates in the index statistics displayed by SHOW INDEX are more accurate for
InnoDB tables.
• To generate execution plans, the optimizer uses a cost model that is based on estimates of the
cost of various operations that occur during query execution. The optimizer has a set of compiled-in
default “cost constants” available to it to make decisions regarding execution plans.
The optimizer now also has a database of cost estimates to use during execution plan construction.
These estimates are stored in the server_cost and engine_cost tables in the mysql system
database and are configurable at any time: Any non-NULL cost estimate stored in the cost model
tables overrides the corresponding compiled-in default estimate. Any NULL estimate indicates to the
optimizer to use the compiled-in default.
Implementation and testing is ongoing to make it safe for DBAs to change these values. Currently,
changing them should be considered at your own risk.
There is also a new FLUSH variant, FLUSH OPTIMIZER_COSTS, that causes the server to reread the
cost tables and apply any changed estimates to new sessions.
For more information, see The Optimizer Cost Model.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the mysql database.
Performance Schema Notes
• Incompatible Change: The Performance Schema now provides a user_variables_by_thread
table that exposes user-defined variables. For more information, see Performance Schema User
Variable Tables.
In consequence of this change, the server now limits user-defined variable names to a maximum of
64 characters, the length of the VARIABLE_NAME column in the table. Previously, the server did not
enforce a limit. The new limit is similar to the limit on the lengths of many other identifiers in MYSQL
(see User-Defined Variables). Queries that use very long user-defined variable names must be
rewritten to user shorter names.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate this change into the performance_schema database.
• Previously, for the wait event tables (such as events_waits_current), the NUMBER_OF_BYTES
column was NULL for table I/O waits; that is, for events for the wait/io/table/sql/handler
instrument. For table I/O waits, this value now indicates the number of rows processed.
In addition, for batch I/O operations (such as row fetches for table or index scans), the Performance
Schema now can report a single event for N rows, rather than reporting a single-row event N times.
This change significantly reduces Performance Schema overhead for table batch I/O by reducing
the number of reporting calls. The tradeoff is lesser accuracy for event timing. Rather than time
183
MySQL 5.7 Release Notes
for an individual row operation as in per-row reporting, timing for batch I/O includes time spent for
operations such as join buffering, aggregation, and returning rows to the client.
For more information on the conditions under which batch I/O reporting occurs, see the description of
the NUMBER_OF_BYTES column in The events_waits_current Table.
• The Performance Schema stage event tables (events_stages_current,
events_stages_history, and events_stages_history_long) contain two new columns that,
taken together, provide a stage progress indicator for each row:
• WORK_COMPLETED: The number of work units completed for the stage
• WORK_ESTIMATED: The number of work units expected for the stage
Each column is NULL if no progress information is provided for an instrument. Interpretation of the
information, if it is available, is entirely up to the instrument implementation. Initially, to demonstrate
the concept, the stage/sql/copy to tmp table instrument provides progress information if it is
enabled. In this case, the unit for interpretation of the columns is number of rows copied.
For more information, see Performance Schema Stage Event Tables.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate this change into the performance_schema database.
Security Notes
• Incompatible Change: MySQL 5.6 deprecated passwords that used the older pre-4.1 password
hashing format. Support for these passwords is now removed, which involves the following changes.
Applications that use any feature no longer supported must be modified.
• The server-side mysql_old_password authentication plugin is removed. Accounts that use this
plugin are disabled at startup and the server writes an “unknown plugin” message to the error
log. For instructions on upgrading accounts that use this plugin, see Migrating Away from Pre-4.1
Password Hashing and the mysql_old_password Plugin.
The client-side mysql_old_password authentication plugin is removed from the C client library.
• The --secure-auth option to the server and client programs is the default, but is now a no-op. It
is deprecated and will be removed in a future MySQL release.
• The --skip-secure-auth option to the server and client programs is no longer supported and
using it produces an error.
• The secure_auth system variable permits only a value of 1; a value of 0 is no longer permitted.
• For the old_passwords system variable, a value of 1 (produce pre-4.1 hashes) is no longer
permitted.
• The OLD_PASSWORD() function is removed.
• The mysqladmin old-password command is removed.
• MySQL now includes a server-side authentication plugin named mysql_no_login for setting up
accounts that accept no client connections. This plugin enables DBAs to implement the following use
cases:
• Stored program and view objects that perform sensitive or adminstrative operations must run with
elevated privileges. Less-privileged users must be able to execute these objects but not be able to
directly log in as the account that has the privileges. To implement this, create a no-login account
using mysql_no_login, grant it the required privileges, define objects with a DEFINER of that
account, and include SQL SECURITY DEFINER in the definitions.
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MySQL 5.7 Release Notes
• Access to a proxy account must always be by the usual proxy mechanism, never by users logging
in directly to the proxy account. To implement this, assign mysql_no_login as the authentication
plugin when you create the proxy account.
For more information, see No-Login Pluggable Authentication.
• MySQL distributions now attempt to deploy with SSL and RSA capabilities enabled by default.
To make it easier to support encrypted connections, MySQL servers compiled using OpenSSL now
can automatically generate SSL and RSA files at startup if they are missing:
• The server automatically generates server-side and client-side SSL certificate and key files in the
data directory if the new auto_generate_certs system variable is enabled, no SSL options
other than --ssl are specified, and the server-side SSL files are missing from the data directory.
These files enable encrypted client connections using SSL.
• The server automatically generates RSA private/public key-pair files in the data directory if the new
sha256_password_auto_generate_rsa_keys system variable is enabled, no RSA options
are specified, and the RSA files are missing from the data directory. These files enable secure
password exchange using RSA over unencrypted connections for accounts authenticated by the
sha256_password plugin.
The server-side --ssl option value now is enabled by default for all servers. For servers compiled
using OpenSSL, if --ssl is enabled and other SSL options are not given to configure SSL explicitly,
the server attempts to enable SSL automatically at startup:
• If the server finds valid SSL files named ca.pem, server-cert.pem, and server-key.pem in
the data directory, it enables SSL to permit SSL connections by clients. (These files need not have
been autogenerated; what matters is that they have the indicated names and are valid.)
• If the server does not find valid SSL files in the data directory, it continues executing but does not
enable SSL.
For any SSL and RSA files that the server finds and uses automatically, it uses the
file names to set the corresponding system variables (ssl_ca, ssl_cert, ssl_key,
sha256_password_private_key_path, sha256_password_public_key_path).
For more information, see Configuring MySQL to Use Encrypted Connections, and Creating SSL and
RSA Certificates and Keys using MySQL.
Spatial Data Support
• InnoDB: SPATIAL indexes can now be used for InnoDB tables. InnoDB supports indexing of
spatial data types, including use of ALTER TABLE ... ALGORITHM=INPLACE for online operations
(ADD SPATIAL INDEX). To support transaction isolation properties, InnoDB uses predicate
locking. A predicate lock locks the minimum bounding rectangle (MBR) used for a query so that other
transactions cannot insert or modify a row that would match the query condition.
For more information, see Optimizing Spatial Analysis. and Predicate Locks for Spatial Indexes. (Bug
#18674219)
• The Open Geospatial Consortium guidelines document the use of open polygons (polygons where
the start point is not equal to the end point) but the MySQL GIS implementation did not support them.
Now MySQL supports open polygons: An open polygon is converted to a closed one by appending
the starting point to the point sequence. Before:
mysql> SELECT AsText(PolygonFromText('POLYGON((10 10,20 10,20 20,10 20))'));
+---------------------------------------------------------------+
| AsText(PolygonFromText('POLYGON((10 10,20 10,20 20,10 20))')) |
+---------------------------------------------------------------+
185
MySQL 5.7 Release Notes
| NULL
|
+---------------------------------------------------------------+
After:
mysql> SELECT AsText(PolygonFromText('POLYGON((10 10,20 10,20 20,10 20))'));
+---------------------------------------------------------------+
| AsText(PolygonFromText('POLYGON((10 10,20 10,20 20,10 20))')) |
+---------------------------------------------------------------+
| POLYGON((10 10,20 10,20 20,10 20,10 10))
|
+---------------------------------------------------------------+
(Bug #17168699)
• GeometryCollection() returned NULL if the argument contained nonsupported geometries. Now
GeometryCollection() returns all the proper geometries contained in the argument even if a
nonsupported geometry is present. (Bug #17168643)
• This MySQL release makes increased use of the Boost.Geometry library to provide better reliability
and increased functionality for spatial functions. As a result, several previously unimplemented
functions have been implemented, and several previously existing functions now accept a wider
range of geometry argument types (or argument type combinations for functions that take multiple
geometries):
• These previously unimplemented spatial operator functions are now available: ST_ConvexHull,
ST_Difference(), ST_Intersection(), ST_SymDifference(), and ST_Union().
• These previously existing functions are more robust and return non-NULL values for more
geometry argument types: ST_Area(), ST_Centroid(), ST_Contains(), ST_Crosses(),
ST_Disjoint(), ST_Distance(), ST_Envelope(), ST_Equals(), ST_Intersects(),
ST_Overlaps(), ST_Touches(), and ST_Within(). These functions also exist as non-ST_
synomyms; for example, ST_Area() and Area() are synonyms.
• MySQL now includes functions for converting between GeoJSON documents and spatial values:
ST_AsGeoJSON() and ST_GeomFromGeoJSON(). For more information, see Spatial GeoJSON
Functions.
• MySQL now includes functions that enable manipulation of geohash values, which provides
applications the capabilities of importing and exporting geohash data, and of indexing and searching
geohash values:
• ST_GeoHash() returns a geohash string given a return value length and either longitude and
latitude values or a POINT value.
• ST_LongFromGeoHash() and ST_LatFromGeoHash() return the longitude or latitude value,
respectively, given a geohash string argument.
• ST_PointFromGeoHash() produces a POINT value from a geohash string argument.
SQL Mode Notes
• Incompatible Change: These SQL mode changes were made:
• Strict SQL mode for transactional storage engines (STRICT_TRANS_TABLES) is now enabled by
default.
• Implementation of the ONLY_FULL_GROUP_BY SQL mode has been made more sophisticated, to
no longer reject deterministic queries that previously were rejected.
• MySQL now recognizes when a nonaggregated selected column is functionally dependent on
(uniquely determined by) GROUP BY columns.
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MySQL 5.7 Release Notes
• MySQL has an extension to standard SQL that permits references in the HAVING clause to
aliased expressions in the select list. Previously, enabling ONLY_FULL_GROUP_BY disables this
extension, thus requiring the HAVING clause to be written using unaliased expressions. This
restriction has been lifted so that the HAVING clause can refer to aliases regardless of whether
ONLY_FULL_GROUP_BY is enabled.
In consequence, ONLY_FULL_GROUP_BY is now enabled by default, to prohibit nondeterministic
queries containing expressions not guaranteed to be uniquely determined within a group.
• The changes to the default SQL mode result in a default sql_mode system variable
value with these modes enabled: ONLY_FULL_GROUP_BY, STRICT_TRANS_TABLES,
NO_ENGINE_SUBSTITUTION.
• The ONLY_FULL_GROUP_BY mode is now included in the modes comprised by the ANSI SQL
mode.
• A new function, ANY_VALUE(), is available that can be used to force MySQL to accept queries
that it thinks should be rejected with ONLY_FULL_GROUP_BY enabled. The function return value
and type are the same as the return value and type of its argument, but the function result is not
checked for the ONLY_FULL_GROUP_BY SQL mode.
If you find that having ONLY_FULL_GROUP_BY enabled causes queries for existing applications to be
rejected, either of these actions should restore operation:
• If it is possible to modify an offending query, do so, either so that nondeterministic nonaggregated
columns are functionally dependent on GROUP BY columns, or by referring to nonaggregated
columns using ANY_VALUE().
• If it is not possible to modify an offending query (for example, if it is generated by a thirdparty application), set the sql_mode system variable at server startup to not enable
ONLY_FULL_GROUP_BY.
For more information about SQL modes and GROUP BY queries, see Server SQL Modes, and
MySQL Handling of GROUP BY. (Bug #18486310)
Functionality Added or Changed
• Incompatible Change: The GET_LOCK() function has been reimplemented using the metadata
locking (MDL) subsystem and its capabilities have been extended:
• Previously, GET_LOCK() permitted acquisition of only one named lock at a time, and a second
GET_LOCK() call released any existing lock. Now GET_LOCK() permits acquisition of more than
one simultaneous named lock and does not release existing locks.
Applications that rely on the behavior of GET_LOCK() releasing any previous lock must be
modified for the new behavior.
• The capability of acquiring multiple locks introduces the possibility of deadlock among clients. The
MDL subsystem detects deadlock and returns an ER_USER_LOCK_DEADLOCK error when this
occurs.
• The MDL subsystem imposes a limit of 64 characters on lock names, so this limit now also applies
to named locks. Previously, no length limit was enforced.
• Locks acquired with GET_LOCK() now appear in the metadata_locks Performance Schema
table. The OBJECT_TYPE column says USER LEVEL LOCK and the OBJECT_NAME column
indicates the lock name.
• A new function, RELEASE_ALL_LOCKS() permits release of all acquired named locks at once.
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MySQL 5.7 Release Notes
For more information, see Miscellaneous Functions.
• Incompatible Change: In MySQL 5.6.6, the YEAR(2) data type was deprecated. Support for
YEAR(2) has now been removed. Once you upgrade to MySQL 5.7.5 or newer, any remaining
YEAR(2) columns must be converted to YEAR(4) to become usable again. For conversion
strategies, see YEAR(2) Limitations and Migrating to YEAR(4). For example, run mysql_upgrade
after upgrading.
• Incompatible Change: Previously, mysql_upgrade performed an upgrade by invoking the mysql
and mysqlcheck clients. mysql_upgrade has been reimplemented to generate the required SQL
statements itself and execute them by communicating directly with server.
In consequence of this change, mysql_upgrade now supports the --bind-address option
enabling the network interface for connecting to the server to be chosen. It also supports -net-buffer-length and --max-allowed-packet options enabling the initial and maximum
communication packet size to be specified.
Also in consequence of this change, mysql_upgrade no longer supports the --tmpdir option.
This option specified the location of temporary files used to supply input to mysql, but it no longer
has any purpose because mysql_upgrade no longer invokes mysql. Any upgrade scripts that
invoke mysql_upgrade and use --tmpdir must be modified to remove that option.
• InnoDB: For optimal shutdown and recovery performance, shutdown and recovery phases are
now supported by the multi-threaded page cleaner feature (innodb_page_cleaners) that was
introduced in MySQL 5.7.4. (Bug #18805275)
• InnoDB: Work was done to introduce the notion of attachable transactions in InnoDB (for
AutoCommit / ReadOnly / ReadCommitted / NonLocking transactions). This is used to read from
InnoDB Data Dictionary tables. Along with this, attachable transactions were exposed to the server.
Data Dictionary access code will use them to read Data Dictionary data.
• InnoDB: You can now truncate undo logs that reside in undo tablespaces. This feature is enabled
using the innodb_undo_log_truncate configuration option. For more information, see
Truncating Undo Tablespaces.
• InnoDB: InnoDB memory allocations now are instrumented for the Performance Schema and will
appear in the memory summary tables.
• InnoDB: Instead of inserting one index record at a time, InnoDB now performs a bulk load when
creating or rebuilding indexes. This method of index creation is also known as a sorted index build.
This enhancement, which improves the efficiency of index creation, also applies to full-text indexes.
Is is not supported with spatial indexes.
A new global configuration option, innodb_fill_factor, defines the percentage of space on each
page that is filled with data during a sorted index build, with the remaining space reserved for future
index growth. For more information, see Sorted Index Builds.
• InnoDB: The FIL_PAGE_FLUSH_LSN field, written to the first page of each InnoDB system
tablespace file and to InnoDB undo tablespace files, is now only written to the first file of the InnoDB
system tablespace (page number 0:0).
As a result of this patch, if you have a multiple-file system tablespace and decide to downgrade from
MySQL 5.7 to MySQL 5.6, you may encounter an invalid message on MySQL 5.6 startup stating
that the log sequence numbers x and y in ibdata files do not match the log
sequence number y in the ib_logfiles. If you encounter this message, restart MySQL 5.6
to ensure that startup has run properly. The invalid message should no longer appear.
• InnoDB: The innodb_buffer_pool_size parameter is now dynamic, allowing you to resize
the buffer pool without restarting the server. The resizing operation, which involves moving pages
to a new location in memory, is performed chunks. Chunk size is configurable using the new
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MySQL 5.7 Release Notes
innodb_buffer_pool_chunk_size configuration option. You can monitor resizing progress
using the new Innodb_buffer_pool_resize_status status variable. For more information, see
Configuring InnoDB Buffer Pool Size Online.
See Configuring InnoDB Buffer Pool Size Online for more information.
• Replication: When replicating from a master running a version earlier than MySQL 5.6.0 to a
slave running MySQL 5.6.0 or later, the slave requires the master_uuid value, which is the
server_uuid value from the master. The master_uuid value is unsupported on the older
master, and in such a replication situation could become invalid on the newer slave. A check for
empty master_uuid now ensures that the slave uses an empty value for master_uuid. (Bug
#18338203)
• Replication: Retrying of transactions is now supported when multi-threading is enabled on a slave.
In previous versions, slave_transaction_retries was treated as equal to 0 when using multithreaded slaves. (Bug #16390504, Bug #68465)
• Replication: Global transaction identifiers (GTIDs) are now logged in a MySQL system table
whenever they are enabled on the server, which lifts a previous requirement to use binary logging
when replicating with GTIDs. If binary logging is disabled, the server stores the GTID for each
transaction in the mysql.gtid_executed table as the transaction is executed. If binary logging is
enabled, then, whenever the binary log is rotated or the server is shut down, the server also writes
into the new binary log the GTIDs for all transactions from the previous binary log.
Because the mysql.gtid_executed table can become filled with many rows with singletransaction GTIDs having the same originating server and sequential transaction IDs, the server
compresses this table periodically whenever GTIDs are enabled. You can control the frequency with
which the table is compressed by setting the executed_gtids_compression_period system
variable. This variable's default value is 1000, which means that compression of the table is applied
following each 1000 transactions. You can set the executed_gtids_compression_period to 0
to disable the compression altogether, but you should be aware that doing this may cause the space
required by this table to increase significantly. (See mysql.gtid_executed Table Compression.)
Compression of the mysql.gtid_executed table is performed by a dedicated thread. You can
obtain information about the state of this thread in the threads Performance Schema table. (Bug
#14730192)
• Replication: The new variable simplified_binlog_gtid_recovery can be used to change the
way binary log files are searched for previous GTIDs during recovery, speeding up the process when
a large number of binary log files exist. (Bug #69097, Bug #16741603, Bug #74071, Bug #19686914)
• Replication: The new system variable binlogging_impossible_mode controls what happens if
the server cannot write to the binary log, for example, due to a file error. For backward compatibility,
the default for binlogging_impossible_mode is IGNORE_ERROR, meaning the server logs the
error, halts logging, and continues updates to the database. Setting this variable to ABORT_SERVER
makes the server halt logging and shut down if it cannot write to the binary log. (Bug #51014, Bug
#11758766)
• Replication: To make monitoring of a replication setup easier, various replication related variables
have been moved to the performance_schema tables. This is particularly helpful for monitoring
multi-source replication.
• Replication: The new SQL function WAIT_FOR_EXECUTED_GTID_SET() makes the current
syncing option for the slave with master independent of the slave threads and improves the return
value.
• Replication: The new options binlog_group_commit_sync_delay and
binlog_group_commit_sync_no_delay_count provide a way to configure the synchronization
of the binary log. This enables more transactions to be synchronized together to disk at once,
reducing the overall time to commit a group of transactions because the larger groups require fewer
time units per group.
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MySQL 5.7 Release Notes
• Replication: Multi-threaded slaves can use the new slave_preserve_commit_order variable
to ensure that the order which transactions were committed on the master is preserved on the slave.
This prevents the slave from entering a state that the master was not in and is well suited to using
multi-threaded slaves for replication read scale-out.
• New Debian7, Ubuntu12.04, and Ubuntu14.04 distribution support that was introduced with 5.6.17
now comes with the platform-specific packaging source placed under the packaging directory, in
the deb-precise, deb-wheezy, and deb-trusty directories. (Bug #19020385)
• CMake support was updated to handle CMake version 3. (Bug #19001781)
• The rwlock used for the SAFE_HASH implementation is now instrumented for the Performance
Schema. The instrument name is wait/synch/rwlock/mysys/SAFE_HASH::lock. (Bug
#18991366)
• The (undocumented) binary-configure.sh script has been removed from MySQL distributions.
(Bug #18694238)
• RHEL 4 is not supported for 5.7, so the support-files/RHEL4-SElinux file was removed. (Bug
#18651087)
• The (undocumented) FEATURE_SET CMake option was removed. (Bug #18521389)
• Unused private fields reported by Clang's -Wunused-private-field compiler warning option
were removed. (Bug #18489724)
• thr_alarm.h and thr_alarm.c were removed because they contain dead code almost
exclusively. The remaining live code was moved to mysqld.cc. my_alarm.h and my_alarm.c
were also removed, and the code from them that is actually used was moved to my_lock.c. (Bug
#18411456)
• The deprecated timed_mutexes system variable has been removed. (Bug #18277305)
• CMake support was updated to handle the new directory layout for Sun C++ 5.13. (Bug #73034, Bug
#19010286)
• The obsolete and unmaintained charset2html utility has been removed from MySQL distributions.
(Bug #71897, Bug #18352347)
• mysqld help text for --general_log was clarified. Thanks to Andrew Gaul for the patch. (Bug
#71463, Bug #18127243)
• The fill_help_tables.sql file that is used to load server-side help table content now contains
the following statement to suppress binary logging and prevent table contents from replicating to
slaves:
SET sql_log_bin=0;
Because help table content is specific to the a particular server version, this prevents loading
incorrect content into the slaves, which do not necessarily run the same version of MySQL as
the master. For more information, see Replication of Server-Side Help Tables. (Bug #69564, Bug
#17015822)
• The empty string provided for numeric or enumeration options (for example, --port="") produced
inconsistent or confusing behavior. Such empty option values now are rejected with an error. (Bug
#68055, Bug #16102788)
• The mysqladmin flush-logs command now permits optional log types to be given, to specify
which logs to flush. Following the flush-logs command, you can provide a space-separated list
of one or more of the following log types: binary, engine, error, general, relay, slow. These
correspond to the log types that can be specified for the FLUSH LOGS SQL statement. Thanks to
Daniël van Eeden for the patch. (Bug #60878, Bug #12368203)
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MySQL 5.7 Release Notes
• A new status variable, Max_used_connections_time, indicates the time at which
Max_used_connections reached its current value. Thanks to Jordi Prats for the patch. (Bug
#59738, Bug #11766596)
• Previously, on Unix and Unix-like systems, MySQL support for sending the server error log to
syslog was implemented by having mysqld_safe capture server error output and pass it to
syslog. The server now includes native syslog support, which has been extended to include
Windows. Server error logging to syslog, Event Log, or a file, should be controlled using mysqld
options. Doing so using mysqld_safe options is now deprecated. For more information about
sending server error output to syslog, see The Error Log.
In addition, system log output control is distinct from sending error output to a file or the console, on
all platforms. Previously, this was true only for Windows. On Unix and Unix-like systems, error output
now can be directed to a file or the console in addition to or instead of the system log as desired.
This is true both for mysqld and mysqld_safe. Previously, mysqld_safe ignored its --syslog
option with a warning if --log-error was also given. (Bug #55370, Bug #11762739)
• If connection IDs went beyond the 32-bit limit and started over at 1, the server now ensures that IDs
still in use will not be reissued. (Bug #44167, Bug #11752851)
• Internally, spatial data types such as Geometry are represented as BLOB values, so when invoked
with the --hex-blob option, mysqldump now displays spatial values in hex. (Bug #43544, Bug
#11752369)
• Scalability for InnoDB tables was improved by avoiding THR_LOCK locks. As a result of this change,
DML statements for InnoDB tables that previously waited for a THR_LOCK lock will wait for a
metadata lock:
• Explicitly or implicitly started transactions that update any table (transactional or nontransactional)
will block and be blocked by LOCK TABLES ... READ for that table. This is similar to how LOCK
TABLES ... WRITE works.
• Tables that are implicitly locked by LOCK TABLES now will be locked using metadata locks
rather than THR_LOCK locks (for InnoDB tables), and locked using metadata locks in addition
to THR_LOCK locks (for all other storage engines). Implicit locks occur for underlying tables of a
locked view, tables used by triggers for a locked table, or tables used by stored programs called
from such views and triggers.
Multiple-table updates now will block and be blocked by concurrent LOCK TABLES ... READ
statements on any table in the update, even if the table is used only for reading.
• HANDLER ... READ for any storage engine will block and be blocked by a concurrent LOCK
TABLES ... WRITE, but now using a metadata lock rather than a THR_LOCK lock.
The preceding changes are visible several ways. For example, when a DML statement such as
INSERT INTO t1 in one session is blocked by LOCK TABLES t1 READ in another session:
• In the Performance Schema, THR_LOCK acquisitions and waits will be registered in the
metadata_locks table and for wait/lock/metadata/sql/mdl events rather than registered
in the table_handles table and for wait/lock/table/sql/handler events.
• In the process list (SHOW PROCESSLIST or INFORMATION_SCHEMA.PROCESSLIST), the state
value will be Waiting for table metadata lock rather than Waiting for table level
lock.
• The Table_locks_immediate and Table_locks_waited status variables will no longer be
incremented.
Issues that went away as a result of these locking changes:
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MySQL 5.7 Release Notes
• For debug builds, concurrent execution of LOCK TABLES ... READ and a DML statement
affecting the same InnoDB table might lead to Found lock of type 6 that is write and
read locked warnings in the error log.
• Execution of DDL statements under LOCK TABLES might have led to deadlock if 1) this LOCK
TABLES statement, in addition to the table to be changed by DDL, also had some tables readlocked or locked implicitly (for example, through triggers) and 2) there was some concurrent DML
which was blocked on a table-level lock held by LOCK TABLES and 3) there was a concurrent
PREPARE (or corresponding connector API call) which prepared a statement using tables to be
affected by the first DDL and some other table which was affected by another DDL statement
which had to wait for the DML statement.
(Bug #42147, Bug #11751331)
• The mysql client now indicates whether USE statements produced warnings. (Bug #29965, Bug
#11746951)
• In the MySQL client/server protocol, EOF and OK packets serve the same purpose, to mark the end
of a query execution result. Due to recent changes in the OK packet (such as session state tracking),
and to avoid repeating the changes in the EOF packet, the EOF packet is now deprecated.
• The server-side help tables and time zone tables in the mysql system database now are InnoDB
(transactional) tables. Previously, these were MyISAM (nontransactional) tables. The affected tables
are:
help_category
help_keyword
help_relation
help_topic
time_zone
time_zone_leap_second
time_zone_name
time_zone_transition
time_zone_transition_type
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the mysql database.
START TRANSACTION and COMMIT statements have been added to the output from
mysql_tzinfo_to_sql used to populate the time zone tables, to ensure that reload operations are
permanent.
• MySQL Server now supports an “offline mode” with these characteristics:
• Connected client users who do not have the SUPER privilege are disconnected on the next
request, with an appropriate error. Disconnection includes terminating running statements and
releasing locks. Such clients also cannot initiate new connections, and receive an appropriate
error.
• Connected client users who have the SUPER privilege are not disconnected, and can initiate new
connections to manage the server.
• Replication slave threads are permitted to keep applying data to the server.
Only users who have the SUPER privilege can control offline mode. To put a server in offline mode,
change the value of the new offline_mode system variable from OFF to ON. To resume normal
operations, change offline_mode from ON to OFF. In offline mode, clients that are refused access
receive an ER_SERVER_OFFLINE_MODE error.
• ALTER TABLE ... EXCHANGE PARTITION syntax now includes an optional {WITH|WITHOUT}
VALIDATION clause. When WITHOUT VALIDATION is specified, ALTER TABLE ... EXCHANGE
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MySQL 5.7 Release Notes
PARTITION does not perform row-by-row validation when exchanging a populated table with the
partition, permitting database administrators to assume responsibility for ensuring that rows are
within the boundaries of the partition definition. WITH VALIDATION is the default behaviour and
need not be specified explicitly. For more information, see Exchanging Partitions and Subpartitions
with Tables.
• mysqlslap now has a --sql-mode option that enables the SQL mode to be set for the client
session.
• It is now possible to specify the storage engine the server uses for on-disk internal
temporary tables (see Internal Temporary Table Use in MySQL), by setting the new
internal_tmp_disk_storage_engine system variable. Permitted values are MYISAM (the
default) and INNODB.
In consequence of this change, the server is no longer prevented from using an in-memory
temporary table for queries containing a string column in a GROUP BY or DISTINCT clause larger
than 512 bytes for binary strings or 512 characters for nonbinary strings.
• The custom rwlock implementation for Windows was replaced with standard Windows API calls. As
a result of this change, Windows binaries require Windows 7 / Windows Server 2008 R2 or newer. In
particular, Windows binaries no longer work on Windows Vista or Windows Server 2008 (plain, not
R2).
• The Boost.Geometry library now is required to build MySQL. Two new CMake options enable control
over the library source location, and whether to download it automatically:
• -DWITH_BOOST=path_name specifies the Boost library directory location. It is also possible to
specify the Boost location by setting the BOOST_ROOT or WITH_BOOST environment variable.
• -DDOWNLOAD_BOOST=bool specifies whether to download the Boost source if it is not present in
the specified location. The default is OFF.
For example, if you normally build MySQL placing the object output in the bld subdirectory of your
MySQL source tree, you can build with Boost like this:
mkdir bld
cd bld
cmake .. -DDOWNLOAD_BOOST=ON -DWITH_BOOST=$HOME/my_boost
This causes Boost to be downloaded into the my_boost directory under your home directory. If the
required Boost version is already there, no download is done. If the required Boost version changes,
the newer version is downloaded.
If Boost is already installed locally and your compiler finds the Boost header files on its own, it may
not be necessary to specify the preceding CMake options. However, if the version of Boost required
by MySQL changes and the locally installed version has not been upgraded, you may have build
problems. Using the CMake options should give you a successful build.
• The deprecated mysqlhotcopy utility has been removed from MySQL distributions. Alternatives
include mysqldump and MySQL Enterprise Backup.
• The deprecated mysqlbug, mysql_waitpid, and mysql_zap utilities have been removed from
MySQL distributions.
• The deprecated storage_engine system variable has been removed. Use
default_storage_engine instead.
Bugs Fixed
• Important Change; Partitioning: In an ALTER TABLE statement, the server accepted REBUILD
with the name of a subpartition as valid syntax even though the REBUILD keyword in this case did
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MySQL 5.7 Release Notes
nothing. Now REBUILD is rejected in such cases, and causes the statement to fail with an error. (Bug
#19075411, Bug #73130)
References: This issue is a regression of: Bug #14028340, Bug #65184.
• Important Change; Replication: A DROP TABLE statement may be divided into multiple statements
before it is sent to the binary log if it contains regular (not temporary) tables and temporary tables,
or if it contains temporary tables using both transactional and non-transactional storage engines.
Now, when using GTIDs, DROP TABLE statements affecting these combinations of tables are
no longer allowed unless the value of the gtid_next system variable is AUTOMATIC. This is
because, with GTIDs enabled on the server, issuing a DROP TABLE in the cases just described
while having only one GTID associated with each statement (the SQL thread does this following SET
gtid_next='uuid:number') causes problems when there are not enough GTIDs for assignment
to all the resulting statements following the division of the original DROP TABLE.
A DROP TABLE statement might be split due to the behavior of the statement with respect to the
current transaction varying, depending on table characteristics, as follows:
• DROP TABLE of a regular (not temporary) table is committed immediately
• DROP TABLE of a temporary table using a transactional storage engine is committed with the
current transaction (following COMMIT)
• DROP TABLE of a temporary table that uses a nontransactional storage engine is committed
immediately
Naming all three of these types of tables in a single DROP TABLE statement causes the MySQL
server to divide the original statement into three separate DROP TABLE statements in the binary
log. If GTIDs are enabled but the value of gtid_next is not AUTOMATIC, issuing a DROP TABLE
statement that mixes any of the table types described previously causes the server to have an
insufficient number of GTIDs to write with all of the resulting statements into the binary log. In
addition, DROP TABLE IF EXISTS is always written in the binary log for all tables specified in the
statement, even if some or all of the tables do not exist.
Because temporary tables are handled differently by DROP TABLE depending on whether they use a
transactional or nontransactional storage engine, any tables named by a DROP TEMPORARY TABLE
statement that do not exist are assumed to be transactional. This means that, if a DROP TEMPORARY
TABLE with two nontransactional temporary tables is issued on the master, it would writes only one
DROP TABLE statement naming both tables. If one of the temporary tables no longer exists on the
slave, then, when the SQL thread executes the statement, it tries to divide it into multiple statements
due to it affecting a nontransactional (but existing) temporary table and a nonexistent transactional
temporary table; this leads to problems because the SQL thread has only one GTID for the original
DROP TABLE statement but must write two DROP TABLE statements in the binary log.
In addition, when the slave dropped temporary tables after detecting that the master had restarted, it
logged one DROP TABLE statement per pseudo-thread and per database, but combined temporary
tables using transactional and nontransactional storage engines in a single DROP TABLE statement.
Now, we throw an error in the client session if gtid_next is set to a uuid:number value and a
DROP TABLE statement is issued mixing any of the table types described previously.
In addition, we now group the nonexistent temporary tables and assume them to be transactional
only if at least one transactional temporary table is dropped by the statement. If no transactional
temporary tables are dropped, any nonexistent temporary tables are assumed to be nontransactional
temporary tables.
The slave now also handles dropping of temporary tables correctly in the event of the restart by the
master. (Bug #17620053)
194
MySQL 5.7 Release Notes
• Important Change; Replication: The maximum length that can be used for the password in
a CHANGE MASTER TO statement is 32 characters. Previously, when a longer password was
employed, it was accepted, but any excess length was silently truncated by the server. Following
this fix, when the password's length exceeds 32 characters, CHANGE MASTER TO fails with an error.
(Bug #11752299, Bug #43439)
• Performance; Replication: When processing the dump thread, a semisynchronous replication
master checked whether or not the dump thread came from a semisynchronous slave by checking
the value of rpl_semi_sync_slave_enabled, but did so for every operation performed on
this thread, which had significant negative impact on performance. Now this check is made only
once, when the dump thread is started, which should noticeably improve the performance of
semisynchronous replication in most cases. (Bug #17932935)
• InnoDB; Partitioning: Large numbers of partitioned InnoDB tables could consume much more
memory when used in MySQL 5.6 or 5.7 than the memory used by the same tables used in previous
releases of the MySQL Server. (Bug #17780517, Bug #70641)
References: This issue is a regression of: Bug #11764622, Bug #57480.
• InnoDB; Linux: The TTASFutexMutex, the mutex implementation that uses the Linux futex, failed
to request m_lock_word alignment. (Bug #19525395, Bug #73760)
• InnoDB: If a crash occurs after a drop index action during a TRUNCATE TABLE operation, the root
page could be left in a free state. On crash recovery, an LSN check failed to check free pages when
attempting to pin the root page, resulting in an assertion. (Bug #19520482)
• InnoDB: Replaced a goto statement with an if statement in the
fil_mutex_enter_and_prepare_for_io function in fil0fil.cc. (Bug #19488149)
• InnoDB: An INSERT operation on a table with spatial data columns raised an assertion. (Bug
#19474851)
• InnoDB: Removed unused code related to binary log information stored in the InnoDB trx_sys
page. (Bug #19471743)
• InnoDB: An ALTER TABLE ... ADD FOREIGN KEY operation could cause a serious error. (Bug
#19471516, Bug #73650)
• InnoDB: Reduced mem_heap_zalloc calls in upd_create. Only a single call is necessary to
allocate memory for upd_t. (Bug #19297656, Bug #73272)
• InnoDB: In debug builds, an INSERT operation affecting compressed tables would raise a syncrelated assertion. (Bug #19295893)
• InnoDB: An ALTER TABLE operation raised an fk_tables.empty() assertion. After calling
dict_load_foreigns(), all associated tables that are linked by a foreign key should be loaded to
ensure that foreign keys are cached. (Bug #19267051)
References: This issue is a regression of: Bug #16244691.
• InnoDB: A transaction returned from the transaction pool was not in a clean state. (Bug #19244969)
• InnoDB: An MLOG_CHECKPOINT marker was incorrectly omitted when performing a log checkpoint.
(Bug #19233510, Bug #73304)
• InnoDB: On crash recovery, InnoDB would call exit() when encountering a corruption or
inconsistency. Some of the exit() calls have been removed to allow InnoDB to shut down
properly. (Bug #19229231, Bug #73300)
• InnoDB: When multiple daemon_memcached_option options are defined, the
INFORMATION_SCHEMA.GLOBAL_VARIABLES table and SHOW VARIABLES statement should only
195
MySQL 5.7 Release Notes
display the first daemon_memcached_option option that is defined in the command line string or in
the MySQL configuration file. (Bug #19204759, Bug #73287)
• InnoDB: Running SHOW ENGINE INNODB STATUS repeatedly under performance testing
conditions could result in a serious error. (Bug #19196052)
• InnoDB: Removed unused one_flush variable from storage/innobase/include/log0log.h.
(Bug #19192364, Bug #73269)
• InnoDB: Retrieval of multiple values with a single get command would return incorrect results
instead of an error message. The InnoDB memcached plugin does not currently support retrieval of
multiple values with a single get command. (Bug #19172212, Bug #72453)
• InnoDB: Attempting to perform operations on a timed out key would cause the memcached daemon
to crash and restart. (Bug #19172013, Bug #72586)
• InnoDB: An ALTER TABLE operation that does not perform a sort on the clustered index could
result in a duplicate record. (Bug #19163915)
References: See also: Bug #17657223.
• InnoDB: Improved error handling, diagnostics, and test coverage related to crash recovery error
handling. (Bug #19145637, Bug #73179)
• InnoDB: Improved error handling for calls to handler::records(). (Bug #19142753)
References: This issue is a regression of: Bug #16802288.
• InnoDB: With a transaction isolation level less than or equal to READ COMMITTED, gap locks were
not taken when scanning a unique secondary index to check for duplicates. As a result, duplicate
check logic failed allowing duplicate key values in the unique secondary index. (Bug #19140907)
References: This issue is a regression of: Bug #16133801.
• InnoDB: A race condition that occurred when dynamically disabling
innodb_adaptive_hash_index caused the purge thread to assert. (Bug #19069698)
• InnoDB: The INNODB_PAGE_ATOMIC_REF_COUNT CMake option is removed in MySQL 5.7.5.
This option was enabled by default but could be disabled for systems that do not support atomic
operations. As of MySQL 5.7.5, support for atomic operations is required to build MySQL, making the
INNODB_PAGE_ATOMIC_REF_COUNT option obsolete. (Bug #19061440)
• InnoDB: In debug builds, an invalid rw_latch == RW_NO_LATCH assertion would cause the server
to halt. (Bug #18977128)
• InnoDB: Added debug assertions to the adaptive hash index code to check that the tablespace ID in
buffer blocks match the index space. (Bug #18965518, Bug #72986)
• InnoDB: During recovery, a segmentation fault would occur when marking a table as corrupt. (Bug
#18942294)
References: This issue is a regression of: Bug #11830883.
• InnoDB: A code comment for the os_event_is_set function in storage/innobase/os/
os0event.cc was incorrect. (Bug #18940008, Bug #72919)
• InnoDB: A latching order violation would occur while inserting BLOB data. (Bug #18883885)
• InnoDB: For PowerPC, InnoDB now uses special PowerPC instructions for setting priority of
hardware threads in InnoDB mutex spin loops. Thanks to Stewart Smith for the contribution. (Bug
#18842925, Bug #72754)
• InnoDB: The innodb_memcached_config.sql configuration script failed after running
the mysql_secure_installation script, which removes the MySQL test database. The
196
MySQL 5.7 Release Notes
innodb_memcached_config.sql script now creates the test database if it does not exist. (Bug
#18816381, Bug #72678)
• InnoDB: Removed unused function definitions and declarations from the InnoDB memcached API.
(Bug #18815992, Bug #72723)
• InnoDB: CACHE_LINE_SIZE for PowerPC was changed from 64 bytes to 128 bytes. (Bug
#18814859, Bug #72718)
• InnoDB: Opening a parent table that has thousands of child tables could result in a long semaphore
wait condition. (Bug #18806829)
• InnoDB: trx_cleanup_at_db_startup failed to reset trx->rsegs->m-redo content in debug
code. (Bug #18795594)
• InnoDB: On mysqld start, specifying multiple data files using the innodb_data_file_path
option would return a Space id in fsp header error after data is written to the second file. (Bug
#18767811)
• InnoDB: When storing BLOB data, InnoDB failed to reserve the required tablespace pages prior to
allocating the pages, which raised an assertion on INSERT. (Bug #18756233)
• InnoDB: A failed in-place ALTER TABLE operation would leave behind non-unique temporary file
names in the data dictionary preventing future ALTER TABLE operations on the same table due
to temporary file name conflicts. To avoid this problem, temporary file names are made unique by
appending a static global number that is initialized to a random distributed 32-bit number using
ut_time() and ut_crc32(). The number is then incremented atomically for each assigned
temporary file name. Previously, temporary files were named using the format #sql-ibtid, where
tid is the table ID. Temporary files are now named using the format #sql-ibtid-inc, where tid
is the table ID and inc is the incremented number. (Bug #18734396, Bug #72594)
• InnoDB: A regression introduced by the fix for Bug #11758237 resulted in a cursor->index>name == TEMP_INDEX_PREFIX assertion. (Bug #18723872)
References: This issue is a regression of: Bug #11758237.
• InnoDB: For single item full-text searches, deleted documents were included in inverse document
frequency (IDF) calculations. (Bug #18711306, Bug #72548)
• InnoDB: The page_create function has been optimized to use simpler functions to initialize pages.
(Bug #18704384)
• InnoDB: A DELETE operation on a table with full-text search indexes raised an assertion. (Bug
#18683832)
References: See also: Bug #14639605.
• InnoDB: To-be-imported tablespace files (FIL_TYPE_IMPORT) were not flushed after being
converted to normal tablespace files (FIL_TYPE_TABLESPACE), resulting in too many open files.
(Bug #18663997)
References: This issue is a regression of: Bug #18236692.
• InnoDB: When InnoDB is built as a shared library, attempting to load the InnoDB full-text
search (FTS) INFORMATION_SCHEMA plugin would fail with a Can't open shared library
'ha_innodb.so' error. (Bug #18655281, Bug #70178)
• InnoDB: When calling the memcached flush_all command, InnoDB attempts to initialize a
connection and a transaction. If the transaction is in TRX_STATE_NOT_STARTED state, InnoDB
failed to set CONN_DATA->CRSR_TRX to NULL, resulting in a serious error. (Bug #18652854)
• InnoDB: An INSERT operation on a table with BLOB columns raised an assertion. (Bug #18646430)
197
MySQL 5.7 Release Notes
References: This issue is a regression of: Bug #16963396.
• InnoDB: An INSERT operation on a table with GEOMETRY columns raised an assertion in
rtr_page_split_and_insert(). (Bug #18644435)
• InnoDB: The temporary tablespace file (ibtmp1) was held open by the page_cleaner thread and
could not be removed on startup, resulting in a hang. (Bug #18642372)
• InnoDB: A regression introduced in MySQL 5.6.5 would cause full-text search index tables to be
created in the system tablespace (space 0) even though innodb_file_per_table was enabled.
(Bug #18635485)
• InnoDB: After upgrading from 5.6.10 to MySQL versions up to and including MySQL 5.6.18, InnoDB
would attempt to rename obsolete full-text search auxiliary tables on server startup, resulting in an
assertion failure. (Bug #18634201, Bug #72079)
• InnoDB: In rare cases, the purge process would attempt to delete a secondary index record that was
not marked for deletion, resulting in an inconsistent secondary index. (Bug #18631496)
• InnoDB: After running OPTIMIZE TABLE on an InnoDB table with a spatial index, running a
SELECT statement that uses the spatial index could result in a crash. (Bug #18619945, Bug #72361)
References: This issue is a regression of: Bug #13975225.
• InnoDB: On startup, with innodb_file_per_table=ON, the page cleaner thread would raise a
srv_get_active_thread_type() == SRV_NONE debug assertion when encountering an active
master thread. (Bug #18598813)
• InnoDB: InnoDB would try to merge a b-tree change buffer for a dedicated undo tablespace. (Bug
#18593561)
• InnoDB: Included unistd.h in innodb.cmake to enable futexes in debug builds. (Bug #18522549,
Bug #72225)
• InnoDB: TRUNCATE TABLE would write page-level redo logs during the DROP TABLE step of a
TRUNCATE TABLE operation. (Bug #18511398)
• InnoDB: A COMMIT operation related to full-text search resulted in a segmentation fault. (Bug
#18503734)
• InnoDB: srv_active_wake_master_thread() was called directly in innobase_commit and
innobase_prepare, waking up the master thread and incrementing srv_activity_count.
srv_active_wake_master_thread() should only be called after committing write
transactions, not after read-only transactions or rollbacks. This patch also replaces some calls
to srv_active_wake_master_thread() with calls to ib_wake_master_thread(). (Bug
#18477009, Bug #72137)
• InnoDB: A DB_LOCK_WAIT during a foreign key check caused redundant delete marking, resulting
in a failing assertion. (Bug #18451287)
• InnoDB: With UNIV_SYNC_DEBUG enabled, a late call to sync_check_enable() would result in
an m_enabled assertion failure. (Bug #18433658)
• InnoDB: InnoDB would write to the redo log for an IMPORT TABLESPACE operation before the
tablespace import was complete. (Bug #18424134)
• InnoDB: The InnoDB memcached plugin would call plugin_del without acquiring the
lock_plugin mutex. This bug fix also addresses a race condition in ib_cursor_delete_row.
(Bug #18409840)
• InnoDB: The os_event_wait_time_low function would sometimes return
OS_SYNC_TIME_EXCEEDED before the sync time has elapsed. (Bug #18386498)
198
MySQL 5.7 Release Notes
• InnoDB: With persistent statistics enabled, SHOW TABLE STATUS output and the TABLE_ROWS
column of INFORMATION_SCHEMA.TABLES could report an incorrect number of table rows for tables
with externally stored pages. (Bug #18384390)
• InnoDB: Running a SELECT on a partitioned table caused a memory access violation in memcpy().
(Bug #18383840)
References: See also: Bug #18167648.
• InnoDB: A regression introduced by the fix for Bug#18069105 could result in a table corruption and
failing assertions. (Bug #18368345)
References: This issue is a regression of: Bug #18069105.
• InnoDB: The data file was not opened prior to calling fil_fusionio_enable_atomic_write(),
resulting in an assertion failure. (Bug #18368241)
• InnoDB: The fix for Bug#17699331 caused a high rate of read/write lock creation and destruction
which resulted in a performance regression. (Bug #18345645, Bug #71708)
References: This issue is a regression of: Bug #17699331.
• InnoDB: Code quality improvements for the redo log subsystem. (Bug #18345004)
• InnoDB: Added the C++ ostream mechanism for error logging. (Bug #18320915)
• InnoDB: Removed the recv_max_parsed_page_no code variable, which was only used in a
diagnostic error message. (Bug #18312967)
• InnoDB: buf_pool->flush_rbt, which is only intended to be used for recovery, would be
allocated for database creation and never freed. (Bug #18253089)
• InnoDB: Calls to sched_getcpu would cause page faults. (Bug #18225489)
• InnoDB: ib_heap_resize failed to verify that new_size is greater than or equal to old_size
before calling memcpy. (Bug #18178915)
• InnoDB: After crash recovery and with UNIV_DEBUG enabled, purge failed with a
buf_pool_from_bpage(bpage) == buf_pool assertion failure. (Bug #18154145)
• InnoDB: Assertion code in buf_page_release_latch() in buf0buf.ic was too restrictive.
(Bug #17869571)
• InnoDB: For each insert, memset would be called three times to allocate memory for system fields.
To reduce CPU usage, the three memset calls are now combined into a single call. (Bug #17858679,
Bug #71014)
• InnoDB: The fix for Bug#16418661 added superfluous buf_flush_list() logic to InnoDB startup
code. (Bug #17798076, Bug #70899)
References: This issue is a regression of: Bug #16418661.
• InnoDB: A problem renaming temporary tables during an ALTER TABLE operation would raise an
assertion and print a warning to the error log. Temporary table names were not sufficiently unique.
(Bug #17713871)
• InnoDB: In-place ALTER TABLE operations requiring a table rebuild would sort the clustered
index even though the primary key order remained unchanged. This behavior caused unnecessary
temporary table usage and I/O. (Bug #17657223)
• InnoDB: Under certain circumstances, adaptive hash index latches (btr_search_latch) were
persistent. With atomics-based rw-locks (read-write locks), persistent adaptive hash index latches
are unnecessary and may block other adaptive hash index updates. (Bug #17554489, Bug #70216)
199
MySQL 5.7 Release Notes
• InnoDB: A race condition in fts_get_next_doc_id resulted in Duplicate FTS_DOC_ID and
Cannot find index FTS_DOC_ID_INDEX in InnoDB index translation table errors.
(Bug #17447086, Bug #70311)
References: See also: Bug #16469399.
• InnoDB: Enabling the InnoDB Table Monitor would result in a ib_table->stat_initialized
assertion failure. (Bug #17039528, Bug #69641)
• InnoDB: Redo log writes for large, externally stored BLOB fields could overwrite the most recent
checkpoint. The 5.6.20 patch limits the size of redo log BLOB writes to 10% of the redo log file size.
The 5.7.5 patch addresses the bug without imposing a limitation. For MySQL 5.5, the bug remains a
known limitation. (Bug #16963396, Bug #19030353, Bug #69477)
• InnoDB: The error log message that is printed on CREATE TABLE when the number of BLOB or
TEXT fields exceed the row size limit did not provide sufficient information. The error message now
provides the maximum row size, current row size, and the field that causes the maximum row size to
be exceeded. (Bug #16874873, Bug #69336)
• InnoDB: An in-place ALTER TABLE operation on a table with a broken foreign key constraint could
raise an assertion. (Bug #16869435)
• InnoDB: The lock_number_of_rows_locked function used a bit vector to track the number of
record locks held by a transaction. To optimize reporting, the bit vector was replaced by a simple
counter. (Bug #16479309, Bug #68647)
• InnoDB: Inserting a record into an InnoDB table with a key that falls between the maximum key of a
full page and the minimum key of the “next” page could result in unnecessary page splits and underfilled pages. If the insert point is at the end of a page, InnoDB now attempts to insert to the next
page before splitting the page. (Bug #15923864, Bug #67718)
• InnoDB: With innodb_max_dirty_pages_pct=0 buffer pool flushing would not be initiated
until the percentage of dirty pages reached at least 1%, which would leave up to 1% of dirty pages
unflushed. (Bug #13029450, Bug #62534)
• InnoDB: Due to differences in memory ordering on different processor types, some mutex and readwrite lock flags were not read consistently. (Bug #11755438, Bug #47213)
• InnoDB: Debug assertion code in file row0ins.cc did not account for rw-lock shared-exclusive (sxlock) mode, resulting in an assertion failure. (Bug #73534, Bug #19420253)
• InnoDB: With foreign_key_checks=0, InnoDB permitted an index required by a foreign key
constraint to be dropped, placing the table into an inconsistent and causing the foreign key check
that occurs at table load to fail. InnoDB now prevents dropping an index required by a foreign key
constraint, even with foreign_key_checks=0. The foreign key constraint must be removed before
dropping the foreign key index. (Bug #70260, Bug #17449901)
• Partitioning: When the index_merge_intersection flag (enabled by default) or the
index_merge_union flag was enabled by the setting of the optimizer_switch system variable,
queries returned incorrect results when executed against partitoned tables that used the MyISAM
storage engine, as well as partitioned InnoDB tables that lacked a primary key. (Bug #18167648)
References: See also: Bug #16862316, Bug #17588348, Bug #17648468.
• Partitioning: Selecting from a table having multiple columns in its primary key and partitioned by
LIST COLUMNS(R), where R was the last (rightmost) column listed in the primary key definition,
returned an incorrect result. (Bug #17909699, Bug #71095)
• Replication: Misleading or confusing error messages have been revised, which were produced in
the following 2 cases when using mysqlbinlog with the --raw option:
• When this option was used together with --include-gtids.
200
MySQL 5.7 Release Notes
• When this option was used together with --exclude-gtids and --read-from-remotemaster=BINLOG-DUMP-NON-GTIDS.
(Bug #19459836, Bug #73625)
• Replication: After the fix for Bug #16861624, killing a multi-threaded slave worker which was waiting
for a commit lock caused a debug assertion to fail. This fix ensures that such a situation can not
occur. (Bug #19311260)
• Replication: Temporary errors related to a slave worker thread which was retrying a transaction
were visible in SHOW SLAVE STATUS. This fix ensures that slave worker threads do not store
temporary errors in the slave status. (Bug #19282301)
• Replication: A corrupted header length in FORMAT_DESCRIPTION_LOG_EVENT could cause
the server to stop unexpectedly. This was due to FORMAT_DESCRIPTION_LOG_EVENT being
considered invalid if the header length was too short. (Bug #19145712)
• Replication: Removed an unnecessary write lock that was taken by an internal function while
adding a GTID to a GTID set, which should improve the performance of the function and the code
dependent on it during such operations. (Bug #18963555, Bug #72977)
• Replication: Semisynchronous replication did not work as expected
when the rpl_semi_sync_master_wait_no_slave and
rpl_semi_sync_master_wait_for_slave_count variables were set. The values of the
variables were changed, but the related internal status was not updated during initialization. (Bug
#18835117, Bug #18466390)
• Replication: RESET SLAVE ALL did not clear IGNORE_SERVER_IDS, although this statement
should clear any values that are set by CHANGE MASTER TO. Now RESET SLAVE ALL always
empties the list of server IDs to ignore, whenever it is executed. (Bug #18816897)
• Replication: The same internal function had effects which caused three similar problems when
resetting or starting slaves. These three issues are listed here:
• RESET SLAVE automatically set the heartbeat period (Slave_heartbeat_period) to its default
value.
• RESET SLAVE automatically set SSL_VERIFY_SERVER_CERT to the default.
• When a server was not configured as a slave (that is, when no CHANGE MASTER TO statement
had yet been executed), the subsequent failure of START SLAVE was expected but had the
unintended side effect of resetting the heartbeat period to the default.
The function has been rewritten such that code affecting heartbeat or SSL certificate usage has been
eliminated or moved to a more appropriate location, eleminating the side effects formerly seen with
RESET SLAVE or a failed START SLAVE.
As part of this fix, in order to be able to keep heartbeats enabled by default when changing the
master, if host and port are given but the heartbeat period is not specified in a CHANGE MASTER TO
statement, we force it to the default value. (Bug #18791604, Bug #18778485, Bug #18777899)
• Replication: mysqlbinlog --raw did not check for errors caused by failed writes, which could
result in silent corruption of binary logs. Now in such cases it stops with an error. (Bug #18742916,
Bug #72597)
• Replication: When committing a transaction, a flag is now used to check whether a thread has been
created, rather than checking the thread itself, which uses more resources, particularly when running
the server with master_info_repository=TABLE. (Bug #18684222)
References: See also: Bug #17967378.
201
MySQL 5.7 Release Notes
• Replication: When a slave worker thread tried to execute a statement that was too large, the
resulting error caused a crash. Now in such cases, the error is truncated to fit the size of the buffer.
(Bug #18563480)
• Replication: Log rotation events could cause group_relay_log_pos to be moved forward
incorrectly within a group. This meant that, when the transaction was retried, or if the SQL thread
was stopped in the middle of a transaction following one or more log rotations (such that the
transaction or group spanned multiple relay log files), part or all of the group was silently skipped.
This issue has been addressed by correcting a problem in the logic used to avoid touching the
coordinates of the SQL thread when updating the log position as part of a relay log rotation whereby
it was possible to update the SQL thread's coordinates when not using a multi-threaded slave, even
in the middle of a group. (Bug #18482854)
• Replication: When using GTIDs with MASTER_AUTO_POSITION enabled, if an I/O thread was
restarted it failed with an ER_GTID_NEXT_TYPE_UNDEFINED_GROUP error due to a partial
transaction not being correctly rolled back before resuming the I/O thread. This fix ensures that the
partial transaction is correctly rolled back. (Bug #18472603)
• Replication: When using row-based replication, updating or deleting a row on the master that did
not exist on the slave led to failure of the slave when it tried to process the change. This problem
occurred with InnoDB tables lacking a primary key. (Bug #18432495, Bug #72085)
• Replication: A multi-threaded slave now checks that a free worker is available to dispatch the
next event. In previous versions, a multi-threaded slave crashes with a worker error if the thread
coordinator can not find a free worker. The crash was caused when the coordinator did not return a
free worker, for example if the coordinator was aborted at the same time using STOP SLAVE. (Bug
#18363515)
• Replication: When replicating from a MySQL 5.5 or earlier master to
a MySQL 5.6 or later slave, the SOURCE_UUID column of the slave's
performance_schema.replication_connection_status table contained random data. Now
in such cases, SOURCE_UUID is left blank. (Bug #18338203)
• Replication: During relay log initialization, the thread context was used as a flag for the
reconstruction of the retrieved GTID set, an operation that does not depend on this parameter. This
could be problematic if relay log initialization was called in another context other than the legacy
replication scenario; if the invocation was made in a context where the thread context was always
present, this prevented the set's reconstruction. The opposite could also happen when the thread
context was not present, which cause the initialization to be performed twice.
To avoid such issues, the thread context flag is replaced with a new flag that allows the
reconstruction in all contexts but prevents multiple invocations. (Bug #18337036)
• Replication: When mysqlbinlog processed multiple binary log files into a single output file,
this file was not in a useful state for point-in-time recovery, when it failed with the error, When
@@SESSION.GTID_NEXT is set to a GTID, you must explicitly set it to
a different value after a COMMIT or ROLLBACK. Please check GTID_NEXT
variable manual page for detailed explanation. Current @@SESSION.GTID_NEXT
is 'xyz'. When mysqlbinlog processes a binary log containing GTIDs, it outputs SET
gtid_next statements, but gtid_next is set to undefined whenever a commit occurs; this left
gtid_next undefined when the server had finished processing the output from mysqlbinlog.
When the next binary log file started with one or more anonymous statements or transactions,
the combination of gtid_next being left undefined at the end of the first binary log and the second
binary log containing anonymous transactions to the error described previously (Error 1837,
ER_GTID_NEXT_TYPE_UNDEFINED_GROUP).
To fix this issue, now, whenever mysqlbinlog encounters this situation, it inserts SET gtid_next
= AUTOMATIC if required to avoid leaving the previous binary log with gtid_next undefined.
202
MySQL 5.7 Release Notes
In addition, as a result of this fix, mysqlbinlog no longer outputs session variable information
for every binary log; now, this value is printed only once unless it changes. (Bug #18258933, Bug
#71695)
• Replication: Quotation marks were not always handled correctly by LOAD DATA INFILE when
written into the binary log. (Bug #18207212, Bug #71603)
• Replication: Changing master_info_repository between TABLE and FILE could produce
duplicate values in the Replicate_Ignore_Server_Ids column of the output from SHOW SLAVE
STATUS and the Ignored_server_ids column of the mysql.slave_master_info table. This
could arise because the list of IDs stored internally by the server was not always sorted before
checking for duplicates when inserting new values into the list. Now the list of server IDs to be
ignored is always sorted, prior to performing this check. (Bug #18192817, Bug #18593479, Bug
#18920203)
• Replication: In certain cases, the server mishandled triggers and stored procedures that tried to
modify other tables when called by CREATE TABLE ... SELECT. This is now handled correctly as
an error. (Bug #18137535)
• Replication: The REPLICATE_WILD_DO_TABLE and REPLICATE_WILD_IGNORE_TABLE options
for CHANGE REPLICATION FILTER could be employed with values which contained no period (.)
character, even though values for these options must be in the format db_name.tbl_name.. (Bug
#18095449)
• Replication: When used on a table employing a transactional storage engine, a failed TRUNCATE
TABLE was still written to the binary log and thus replayed on the slave. This could lead to
inconsistency when the master retained data that was removed on the slave.
Now in such cases TRUNCATE TABLE is logged only when it executes successfully. (Bug
#17942050, Bug #71070)
• Replication: Beginning in MySQL 5.6.20, when a user specified AUTO_INCREMENT value falls
outside of the range between the current AUTO_INCREMENT value and the sum of the current and
number of rows affected values it is replicated correctly. In previous versions, an error was generated
by the slave even if the user specified AUTO_INCREMENT value fell outside of the range. (Bug
#17588419, Bug #70583)
• Replication: When the I/O thread reconnected to a master using GTIDs and multithreaded slaves
while in the middle of a transaction, it failed to abort the transaction, leaving a partial transaction
in the relay log, and then retrieving the same transaction again. This occurred when performing a
rotation of the relay log. Now when reconnecting, the server checks before rotating the log in such
cases, and waits first for any ongoing transaction to complete. (Bug #17326020)
• Replication: On Windows, mysqldump failed if the error log file was deleted (missing) from the
active MySQL server. (Bug #17076131)
• Replication: When the binary log was rotated due to receipt of a SIGHUP signal, the new binary log
did not contain the Previous_gtid_event required for subsequent processing of that binary log's
GTID events. Now when SIGHUP is received, steps are taken to insure that the server writes the
necessary Previous_gtid_event to the new log before writing any GTID events to the new log.
(Bug #17026898)
• Replication: The CLIENT_REMEMBER_OPTIONS flag for compressed slave connections is no longer
reset and all options are retained. This restores functionality of all options to compressed slave
connections. (Bug #72901, Bug #18923691, Bug #73324, Bug #19244772)
• Replication: When using row-based replication, setting a slave's
slave_rows_search_algorithms variable to HASH_SCAN caused an ER_KEY_NOT_FOUND error
even though that record existed in the storage layer. This fix ensures that the unique key for each
record is correctly maintained and such a situation does not occur. (Bug #72788, Bug #18860225)
203
MySQL 5.7 Release Notes
• Replication: When using row-based replication, running a long transaction involving a large
number of events could trigger an Out of Memory (OOM) error if the slave's table structure was not
compatible with the master's table structure. Such an incompatible situation could occur if the table
on the slave had been manually changed, or when replicating between different MySQL versions that
have different data types. This OOM error was caused because the virtual temporary tables created
for the row conversion were not being freed until the end of the transaction, which was a problem
when replicating large numbers of events.
Starting with this version, such virtual tables are correctly freed during the conversion process. (Bug
#72610, Bug #18770469)
References: See also: Bug #19692387.
• Replication: The error messages generated when a duplicate server UUID causes issues during
replication have been improved. The slave error now identifies the duplicate server UUID and the
master error identifies the zombie thread that has been killed. (Bug #72578, Bug #18731211)
• Replication: When an event group was spanned across multiple relay log files, a slave could
incorrectly identify GTID-header group boundaries. This meant that when a transaction was
retried, or if the SQL thread was stopped in the middle of a transaction after some rotates,
the Gtid_log_event was being silently skipped on the slave, and the transaction was
logged with the slave's GTID. This problem also impacted on using START SLAVE UNTIL
MASTER_LOG_POS = log_pos; with GTIDs enabled. If log_pos was in the middle of a
transaction, the Gtid_log_event was not correctly detected as the beginning of the transaction
and replication stopped before this event. With this fix, threads correctly detect that they are part of
a group, and this is used to check if a Gtid_log_event is part of a transaction. (Bug #72313, Bug
#18652178, Bug #18306199)
• Replication: When gtid_mode=ON, and a transaction is filtered out on the slave, the GTID of the
transaction is still logged on the slave as an “empty” transaction (consisting of a GTID followed
immediately by BEGIN and then COMMIT). This is necessary to prevent the transaction from being
retransmitted the next time the slave reconnects or is involved in a failover. The current fix addresses
two issues relating to such “empty” transactions:
• No empty transaction was generated for CREATE TEMPORARY TABLE or DROP TEMPORARY
TABLE statements.
• If the slave used a database filter (--replicate-do-db or --replicate-ignore-db option),
no empty transaction was generated.
(Bug #71376, Bug #18095502, Bug #18145032)
• Replication: Client applications should be able to set the BINLOG_DUMP_NON_BLOCK flag in
the initial handshake packet (COM_BINLOG_DUMP). Clients connecting to a server issuing a
COM_BINLOG_DUMP with the flag unset do not get an EOF when the server has sent the last event
in the binary log, which causes the connection to block. This flag, which was removed in error in
MySQL 5.6.5, is now restored in the current release.
As part of this fix, a new --connection-server-id option is added to mysqlbinlog. This option
can be used by the client to test a MySQL server for the presence of this issue. (Bug #71178, Bug
#18000079)
• Replication: On a master that is using semisynchronous replication, where
rpl_semi_sync_master_wait_no_slave is enabled and rpl_semi_sync_master_timeout
is set to long timeout, killing the I/O thread could cause the server to hang on shutdown. This fix
ensures that if the dump thread finds that there no semisynchronous slaves connected to the master,
the setting of rpl_semi_sync_master_wait_no_slave is ignored and the shutdown proceeds
correctly. (Bug #71047, Bug #17879675)
• Replication: Uninstalling and reinstalling semisynchronous replication plugins while
semisynchronous replication was active caused replication failures. The plugins now check whether
204
MySQL 5.7 Release Notes
they can be uninstalled and produce an error if semisynchronous replication is active. To uninstall
the master-side plugin, there must be no semisynchronous slaves. To uninstall the slave-side plugin,
there must be no semisynchronous I/O threads running. (Bug #70391, Bug #17638477)
• Replication: When using semisynchronous replication, if the binary log position was changed to a
future position on a slave then an assertion error was generated on the master. This fix ensures that
in such a situation the future position is correctly acknowledged and an error is instead generated on
the slave. (Bug #70327, Bug #17453826)
• Replication: Replication of tables that contained temporal type fields (such as TIMESTAMP,
DATETIME, and TIME) from different MySQL versions failed due to incompatible TIMESTAMP types.
The fractional TIMESTAMP format added in MySQL 5.6.4 was not being correctly converted. You can
now replicate a TIMESTAMP in either format correctly according to the slave_type_conversions
variable. (Bug #70124, Bug #17532932)
• Replication: A group of threads involved in acquiring locks could deadlock when the following
events occurred:
1. Dump thread reconnects from slave; on master, a new dump thread tries to kill zombie dump
threads; having acquired the thread's LOCK_thd_data, it is about to acquire LOCK_log.
2. Application thread executing show binary logs, having acquired LOCK_log and about to acquire
LOCK_index.
3. Application thread executing PURGE BINARY LOGS; having acquired LOCK_index, it is about to
acquire LOCK_thread_count.
4. Application thread executing SHOW PROCESSLIST (or SELECT * FROM
INFORMATION_SCHEMA.PROCESSLIST), having acquired LOCK_thread_count and about to
acquire the zombie dump thread's LOCK_thd_data.
This leads to the 4 threads deadlocking in the same order which the threads have been listed here.
This problem arises because there are ordering rules for LOCK_log and LOCK_index, as well as
rules for ordering LOCK_thread_count and LOCK_thd_data, but there are no rules for ordering
across these two sets of locks. This was because the internal mysqld_list_processes()
function invoked by SHOW PROCESSLIST acquired LOCK_thread_count for the complete lifetime
of the function as well as acquiring and releasing each thread's LOCK_thd_data. Now this function
takes a copy of the threads from the global thread list and performs its traversal on these, and only
after releasing LOCK_thread_count. During this traversal, removal from the global thread list is
blocked using LOCK_thd_remove such that the copies that would otherwise be destroyed by the
removal remain valid during traversal. The locking order following this fix is shown here:
LOCK_thd_remove -> LOCK_thd_data -> LOCK_log -> LOCK_index -> LOCK_thread_count
(Bug #69954, Bug #17283409)
References: See also: Bug #73475, Bug #19364731, Bug #19365180.
• Replication: When an SQL thread which was waiting for a commit lock was killed and restarted
it caused a transaction to be skipped on slave. This fix ensures that thread positions are correctly
persisted and transactions resume at the correct position. (Bug #69873, Bug #17450876)
• Microsoft Windows: To help with crash analysis on Windows, more information has been added
to the core file that is written on mysqld abort when the core-file option is enabled. (Bug
#14041454)
• With DTrace support enabled, certain other compilation options could cause the build to fail. (Bug
#19506247)
205
MySQL 5.7 Release Notes
• yaSSL client code did not validate the encryption size or session ID length, which could cause the
client to exit. (Bug #19463277, Bug #19463565)
• Before fsync operations, the server reports a wait, but it reported a table-lock wait rather than a sync
wait. This is a minor problem, possibly resulting in come incorrect thread pool plugin statistics. (Bug
#19428231)
• The optimizer could raise an assertion due to incorrectly handling the table map while sorting an
internal temporary table. (Bug #19416826)
• yaSSL could fail preauthorization if the client supplied inaccurate buffer lengths. (Bug #19370676,
Bug #19355577)
• Using Multi-Range Read (MRR) for table access could leak Performance Schema instrumented table
handles. (Bug #19301539)
• For InnoDB full-text searches, invalid multibyte gb10830 characters could cause a server exit. (Bug
#19233075)
• Competition between threads could lead to timeout failure trying to rotate the audit log file. (Bug
#19184973)
• On Windows, sql_yacc.cc and sql_yacc.h were generated twice during the build process. This
can lead to compilation failure if parallel processes are permitted. (Bug #19060850)
• Repetitive functions called as arguments to ExtractValue() were not always handled correctly.
(Bug #19051306)
• For large sets, EXPORT_SET() could produce undefined results or a cause a server exit. (Bug
#19048609)
• Invalid utf16 data could cause the server to become unresponsive. (Bug #18937504)
• LPAD() and RPAD() could cause a server exit if the pad string argument was not well formed. (Bug
#18935421)
• The optimizer could create a zero-length column for a temporary table, causing a server exit. (Bug
#18928848)
• In debug builds, certain range queries could cause an assertion failure. (Bug #18921626)
• Improper copying of query strings between the Prepared_statement and THD data structures
could result in a server exit. (Bug #18920075)
• Performance Schema memory instrumentation did not honor the ENABLED flag in the
setup_instruments table or the consumers in the setup_consumers table. This has been
corrected, with the result that unnecessary statistics are not collected and overhead is reduced. (Bug
#18900309)
• When a SELECT included a derived table in a join in its FROM list and the SELECT list included
COUNT(DISTINCT), the COUNT() returned 1 even if the underlying result set was empty. (Bug
#18853696)
References: This issue is a regression of: Bug #11760197.
• Conversion failure of “zero” dates in strict SQL mode could cause a server exit. (Bug #18840123)
• Modulo operations on DECIMAL values in some cases could overflow and cause a server exit. (Bug
#18839617)
• Enabling optimizer trace could cause a server exit for queries with a subquery in a HAVING clause.
(Bug #18791851)
206
MySQL 5.7 Release Notes
• SHA and MD5 functions failed for operations using the internal filename character set and could
cause a server exit. (Bug #18786138)
• Large arguments passed to mysqldump could lead to buffer overflow and program exit. (Bug
#18779944)
• If a materialized subquery read from a view, and contained an inner subquery having an outer
reference to a column of the view, results could be incorrect. (Bug #18770217)
• Passing bad arguments to SHA2() could cause a server exit. (Bug #18767104)
• Spatial operations on InnoDB tables could fail attempting to access nonexistent index statistics.
(Bug #18743725)
• ORDER BY of a GIS function that was given invalid arguments could cause a server exit. (Bug
#18701868)
• The code for processing the gb18030 character set had a too-strict assertion for single-character
invalid characters. (Bug #18700668)
• After a metadata change, a reprepared trigger could cause a server exit or prune an incorrect
partition. (Bug #18684393)
• mysql_secure_installation ignored options defined after an unrecognized option. (Bug
#18659533)
• VALIDATE_PASSWORD_STRENGTH() could enter an infinite loop for some arguments. (Bug
#18636291)
• ALTER TABLE on a partitioned table could result in the wrong storage engine being written into the
table's .frm file and displayed in SHOW CREATE TABLE. (Bug #18618561)
• The server could fail to properly reprepare triggers that referred to another table after that table was
truncated. (Bug #18596756, Bug #72446, Bug #18665853)
• Compiler flags were not passed to DTrace, causing problems for 32-bit builds cross-compiled on 64bit platforms. (Bug #18593044)
• For conditions on the form t.key NOT IN (c1, c2, ...), if one or more of the c1, c2 was
NULL, the optimizer generated incorrect range predicates, possibly yielding incorrect results.
The range optimizer would build predicates for empty in-lists (because NULL values are removed
from NOT IN (in-list)). (Bug #18556403, Bug #18715670)
• After conversion of an in-memory internal temporary table to disk, the server could use a pointer to
the old table, resulting in a server exit. (Bug #18535226)
• For queries executed using Loose Index Scan, incorrect cost estimates could be produced if index
statistics were unavailable. (Bug #18497308)
• Setting default_storage_engine to a bad value could cause server failure later. (Bug
#18487724)
• In debug builds, MAKE_SET() within a GROUP BY clause raised an assertion. (Bug #18487060)
• In debug builds, subquery optimization could be overly aggressive about raising an assertion. (Bug
#18486607)
• In debug builds, a qsort operation on decimal values could raise an assertion. (Bug #18486249)
• For debug builds, an assertion was raised for attempts using a cursor within a stored routine to fetch
a large value (INT) which cannot fit into a variable (TINYINT). (Bug #18484649)
• MOD for very small decimal right-hand arguments could cause a server exit. (Bug #18469276)
207
MySQL 5.7 Release Notes
• With the max_heap_table_size system variable set to a large value (20GB), creation of a
temporary table or a table using the MEMORY storage engine caused a server exit. (Bug #18463911)
• mysql_session_track_get_first() and mysql_session_track_get_next() returned
information only when the type argument was SESSION_TRACK_SYSTEM_VARIABLES, and
returned information for all types, not just SESSION_TRACK_SYSTEM_VARIABLES. Now they return
information of the type requested and only that type. (Bug #18463441)
• For mysql_upgrade, specifying the --defaults-extra-file with a nonexisting file caused a
segmentation fault on some platforms. (Bug #18443096)
• Assigning some values to the session_track_system_variables system variable could cause
a server exit. (Bug #18405677)
• mysql_install_db could hang while reading /dev/random to generate a random root
password. (Bug #18395378)
• EXPLAIN FOR CONNECTION showed an incorrect filtering value for dynamic range queries. (Bug
#18395059)
• The client library now includes a call to X509_verify_cert_error_string() in the SSL
certificate verification code, to be more robust in detecting invalid certificates. (Bug #18384260)
• Queries that use AES_ENCRYPT(), AES_DECRYPT(), or RANDOM_BYTES() cannot be cached but
were permitted to enter the query cache. (Bug #18383169)
• If MySQL was built with the -DINSTALL_LIBDIR=lib64 option, mysql_config did not work
if the MySQL package was unpacked into a location with a different installation prefix. Also,
mysql_config did not work for some RPM builds because it used an incorrect installation prefix.
(Bug #18382225)
• Plugin registration code in the embedded server (compiled without the Performance Schema) failed
for plugins compiled with the Performance Schema. (Bug #18363910)
• For indexes on prefixes or character string columns, index corruption could occur for assignment of
binary data to the column due to improper character counting. (Bug #18359924)
• The HAVE_IB_LINUX_FUTEX CMake check failed due to a missing include file. (Bug #18353271)
• After a code reorganization in MySQL 5.7.4, ORDER BY for multiple-table UPDATE statements was
ignored. (Bug #18352634)
• The addition in MySQL 5.7.4 of session state information to the OK packet of the client/server
protocol caused the mysql->info member to be missing a terminating null terminator. (Bug
#18349102)
• Improper linking of join caches by the optimizer could lead to a server exit. (Bug #18335908)
• In debug builds, lack of proper object initialization of decimal objects caused an assertion to be
raised. (Bug #18335446)
• UNCOMPRESSED_LENGTH() could return NULL when it should not have. (Bug #18335269)
• On Windows, some test cases ran too slowly due to mysqltest not testing properly for server
termination. (Bug #18330694)
• The COM_RESET_CONNECTION command did not reset some session system variables:
rand_seed1, rand_seed2, timestamp. Also, it did not clear warnings, and, although it reset the
profiling variable, it did not reset profiling information. (Bug #18329348, Bug #18329560, Bug
#18328396, Bug #18329452)
• Certain INFORMATION_SCHEMA queries could cause a server exit. (Bug #18319790)
208
MySQL 5.7 Release Notes
• EXPLAIN for some full-text queries could raise an assertion. (Bug #18313651)
• Solaris-specific scripts were included in and installed by non-Solaris packages. (Bug #18305641)
• DELETE is not allowed on views defined as joins on the base tables. However, MySQL incorrectly
permitted REPLACE (which is like a combination of DELETE and INSERT) on such views. (Bug
#18286777)
• For debug builds, a 0x00 character in a full-text query string that used the ujis_japanese_ci,
utf8mb4_turkish_ci, or eucjpms_bin collation could raise an assertion. (Bug #18277305)
• innobase_strnxfrm() wrote one byte too many. (Bug #18277082)
• On Windows, use of the gb18030_unicode_520_ci caused a server exit. (Bug #18271429)
• The internal likely() and unlikely() macros conflicted with Boost symbols. To resolve this, the
macros were converted to inline functions. (Bug #18242233)
• If the left-hand-side of an IN predicate was a scalar subquery but returned no row, the server could
exit. (Bug #18223655, Bug #18447874)
• For queries involving an AND of two geometry ranges, the optimizer could decide no index was
usable but try to use it anyway, resulting in a server exit. (Bug #18220153)
• Argument checking for a memmove() call in my_net_read() was improved. (Bug #18184793)
• mysql_upgrade invoked the mysql and mysqlcheck clients and the command arguments could
be visible to other processes. This issue is addressed by the reimplementation of mysql_upgrade
to communicate directly with the server, a change described elsewhere in these release notes. (Bug
#18180398)
• yaSSL code had an off-by-one error in certificate decoding that could cause buffer overflow.
yaSSL code had an opendir() without a corresponding closedir(). (Bug #18178997, Bug
#17201924)
• EXPLAIN on a query with an EXISTS subquery containing a UNION could cause a server exit.
Multiple executions of a prepared EXPLAIN on a UNION of subqueries could cause a server exit.
(Bug #18167356)
• mysqladmin password masked the old password given on the command line, but not the new
password. (Bug #18163964)
• For InnoDB tables, boolean full-text queries for terms ending with * could return incorrect results.
(Bug #18128757)
• For XA transactions, -1 could be assigned as the format ID part of an XID value, resulting in
mishandling (server hang or exit) of concurrent XA statements. (Bug #18107853)
• The client library could cause clients to exit due to incorrectly mapping the client error number to the
corresponding message, if reallocation of packet buffer memory occurred. (Bug #18080920)
• For full-text queries on InnoDB tables, attempts to access deleted document IDs could lead to a
server exit. (Bug #18079671)
• The optimizer could compute a negative cost value when constructing an execution plan for MERGE
table queries. (Bug #18066518)
• Executing a correlated subquery on an ARCHIVE table which has an AUTO_INCREMENT column
caused the server to hang. (Bug #18065452)
• Calling mysql_get_server_version() with an invalid connection handler argument caused the
client to exit. Now it returns 0 and reports a CR_COMMANDS_OUT_OF_SYNC error. (Bug #18053212)
209
MySQL 5.7 Release Notes
• MyISAM temporary files could be used to mount a code-execution attack. (Bug #18045646)
• If the optimizer chose to perform an index scan, in some cases it could choose a noncovering rather
than a covering index. (Bug #18035906)
• The CMake -DWITHOUT_PARTITION_STORAGE_ENGINE=1 option did not work.
As part of fixing this problem, a preferred syntax for disabling storage engines was
implmented. The syntax -DWITH_engine_STORAGE_ENGINE=0 is now preferred to DWITHOUT_engine_STORAGE_ENGINE=1. For example, use:
-DWITH_EXAMPLE_STORAGE_ENGINE=0
-DWITH_FEDERATED_STORAGE_ENGINE=0
-DWITH_PARTITION_STORAGE_ENGINE=0
Rather than:
-DWITHOUT_EXAMPLE_STORAGE_ENGINE=1
-DWITHOUT_FEDERATED_STORAGE_ENGINE=1
-DWITHOUT_PARTITION_STORAGE_ENGINE=1
(Bug #17947926)
• The C client library could leak memory when client plugins were used. (Bug #17933308)
• For debug builds, DROP FUNCTION with a too-long function name raised an assertion. (Bug
#17903490)
• A BEFORE UPDATE trigger could insert NULL into a NOT NULL column. (Bug #17864349)
• A UNION ALL query with SQL_CALC_FOUND_ROWS and a LIMIT with an offset for one query block
reported an incorrect number of found rows. (Bug #17833261)
• For debug builds, a DELETE statement with a subquery that returned multiple rows in a context
requiring a scalar subquery could raise a diagnostic area assertion. (Bug #17787664)
• Using an outer reference in a GROUP BY or ORDER BY clause in a subquery could cause a server
exit. (Bug #17748273)
• For queries that selected from the events_statements_current Performance Schema table,
adding an ORDER BY clause could produce incorrect results. (Bug #17729044)
• A (rare) deadlock could occur between LOCK_thd_data and the InnoDB trx_sys mutex. One
thread could read a query string while it was being removed by another thread. (Bug #17606098)
• On Windows, calling mysql_thread_init() call without mysql_init() caused the client to
exit. windows. Now it returns a nonzero result because it is an error to call mysql_thread_init()
before the client library is initialized with mysql_library_init(). (Bug #17514920)
• For REPLACE on a view, a row being replaced in a view might conflict with one or more rows in the
base table, some of which might not be accessible by the view. In some cases, rows inaccessible by
the view could be replaced. (Bug #17487701)
• mysqldump could create table definitions in the dump file that resulted in Too many columns
errors when reloading the dump file. (Bug #17477959)
• Using LOAD DATA INFILE to load fixed-length data into a view could cause a server exit. (Bug
#17458965)
• The optimizer trace could cause a server exit in cases where a subquery was transformed away.
(Bug #17458054)
• UPDATE statements that modified full-text indexes could cause a server exit. (Bug #17457755)
210
MySQL 5.7 Release Notes
• Sending a SIGQUIT or SIGINT signal to mysql could result in a glibc double free or corruption
error. (Bug #17297324)
• A server could have its socket file taken over by a second server listening on different TCP/IP port
but the same socket file. The socket file also would be unlinked by normal shutdown of the second
server. To avoid this, the server now uses a lock file with the same name as the socket file and a
.lock suffix. (For example, /tmp/mysql.sock has a lock file of /tmp/mysql.sock.lock.) The
lock file contains the process ID of the server process that created the socket file. (Bug #17286856)
• If a query had both MIN()/MAX() and aggregate_function(DISTINCT) (for example,
SUM(DISTINCT)) and was executed using Loose Index Scan, the result values of MIN()/MAX()
were set improperly. (Bug #17217128)
• For UNION statements, the rows-examined value was calculated incorrectly. This was manifest as
too-large values for the ROWS_EXAMINED column of Performance Schema statement tables (such as
events_statements_current). (Bug #17059925)
• When joining one large table without indexes to a number of smaller tables with indexes, the
optimizer chose to join on the large table as the last table, causing a large number of large table
scans. (Bug #16838146)
• Row constructor arguments to INTERVAL() could cause a server exit. (Bug #16439419)
• An assertion could be raised when creating a index on a prefix of a TINYBLOB or GEOMETRY column
in an InnoDB column. (Bug #16368875, Bug #18776592, Bug #17665767)
• mysql_config_editor left some files open when they were no longer needed, resulting in
Valgrind warnings. (Bug #16368498)
• Several issues related to the ONLY_FULL_GROUP_BY SQL mode were corrected:
• With ONLY_FULL_GROUP_BY enabled, some valid queries were rejected if the accessed table was
replaced by a view.
• Queries of the form SELECT DISTINCT col1 ... ORDER BY col2 qualify as forbidden by
SQL2003 (hidden ORDER BY columns combined with DISTINCT), but were not rejected with the
ONLY_FULL_GROUP_BY SQL mode enabled.
(Bug #16021396, Bug #18993257, Bug #13581713)
• The change made in MySQL 5.7.0 to display the XID value in hexadecimal for XA RECOVER if it
contained nonprintable characters was reverted because it caused problems for some clients. Now
the statement takes an optional CONVERT XID keyword so that clients can request the XID value in
hexadecimal on demand. (Bug #14670465)
• Use of a nonmultibyte algorithm for skipping leading spaces in multibyte strings could cause a server
exit. (Bug #12368495, Bug #18315770)
• Executing a DELETE statement on a table with no key in safe-update mode resulted in an
ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE error. For debug builds, using IGNORE in the the
statement resulted in an assertion being raised. (Bug #74493, Bug #19873291)
• Binary MySQL distributions for OS X 10.8 and up now bundle the MySQL.prefPane and
MySQLStartupItem.pkg tools into the main package as configurable options instead of separate
packages. (Bug #74123, Bug #19701502)
• For debug builds, a SELECT under load from the events_statements_current Performance
Schema table could raise an assertion. (Bug #73530, Bug #19419463)
• mysql_secure_installation failed to run properly if the root account authentication plugin
was sha256_password. (Bug #73148, Bug #19127636)
211
MySQL 5.7 Release Notes
• The server did not take the lower_case_table_names value into account in determining the
database directory from which to read the db.opts file, and thus could read the file from an
incorrect directory. (Bug #72900, Bug #18923685)
• SHA2() failed to return NULL if the hash-length argument was NULL or not one of the permitted
values. (Bug #72856, Bug #18899869)
• mysql_install_db failed to create the initial root account if autocommit was disabled. (Bug
#72724, Bug #18911807)
• The mysql client displayed gb18030 data incorrectly. (Bug #72573, Bug #18726196)
• The gb18030_chinese_ci collation treated 'Y' equal to '~'. (Bug #72565, Bug #18729428)
• The query cache was not invalidated for a table when a CASCADE DELETE or CASCADE UPDATE
referential constraint was specified and the database name or table name contained special
characters. (Bug #72547, Bug #18710853)
• NOW(N) in a view definition was stored as NOW(), thus losing the fractional seconds part. (Bug
#72472, Bug #18675237)
• If a prepared statement being executed produced an error, the server failed to write the statement to
the general query log. (Bug #72375, Bug #18616826)
• A new CMake option, SUNPRO_CXX_LIBRARY, enables linking against libCstd instead of
stlport4 on Solaris 10 or later. This works only for client code because the server depends on C+
+98. Example usage:
cmake -DWITHOUT_SERVER=1 -DSUNPRO_CXX_LIBRARY=Cstd
(Bug #72352, Bug #18605389)
• A SELECT statement using a subquery with UNION and ORDER BY did not permit use of an alias in
the outer statement. (Bug #72189, Bug #18498344)
• UNION queries with an aggregate function in an ORDER BY clause were not rejected as they should
be. Now such queries are rejected with an ER_AGGREGATE_ORDER_FOR_UNION error. Example:
SELECT 1 AS foo UNION SELECT 2 ORDER BY MAX(1);
A nonaggregated query with an ORDER BY applied to it cannot contain aggregate
functions, but was not rejected as it should be. Now such queries are rejected with an
ER_AGGREGATE_ORDER_NON_AGG_QUERY error. Example:
SELECT a FROM t1 ORDER BY COUNT(*);
(Bug #72174, Bug #18503515, Bug #72512, Bug #18694751)
• MOD operations on a DECIMAL value with leading zeros could produce incorrect results. (Bug
#72100, Bug #18509896)
• mysqlslap accepted an --iterations option value of 0, which resulted in a divide-by-zero error.
The minimum option value now is 1. Thanks to Tsubasa Tanaka for the patch. (Bug #72082, Bug
#18430704)
• mysql_upgrade could fail if the mysql.user table contained multiple accounts with the same user
name and host name where the host name differed in lettercase. This is still not permitted, but now
mysql_upgrade prints a more informative error message to indicate the nature of the problem:
ERROR 1644 (45000): Multiple accounts exist for user_name, host_name
212
MySQL 5.7 Release Notes
that differ only in Host lettercase; remove all except one of them
(Bug #72066, Bug #18415196)
• ER_CANT_CREATE_GEOMETRY_OBJECT was treated as a fatal error, thus not catchable with
condition handlers. (Bug #72064, Bug #18413646)
• Some comparisons between BIGINT signed and unsigned values could yield incorrect results. (Bug
#72046, Bug #18408499)
• For IN() predicates with values different from the key data value, the optimizer sometimes used a
table scan when it could do a range scan. (Bug #71962, Bug #18364815)
• mysql_config_editor exited when given an empty argument to the --login-path option. (Bug
#71837, Bug #18311024, Bug #18830493)
• Upgrades using RPM packages could change the ownership of an installation directory. (Bug
#71715, Bug #18281535)
• The threads Performance Schema table displayed a PROCESS_ID value of NULL
for replication threads. Now it displays the same ID as SHOW PROCESSLIST and the
INFORMATION_SCHEMA.PROCESSLIST table. (Bug #71682, Bug #18259356)
• In the DIGEST_TEXT column of Performance Schema statement events tables, references to system
variables of the form @@var_name were stored as @ @ var_name. (Bug #71634, Bug #18304086)
• For mysqldump, dump and restore operations failed for database names that contained backslash
('\'). Thanks for Xiaobin Lin for the patch. (Bug #71437, Bug #18109728)
• A simultaneous OPTIMIZE TABLE and online ALTER TABLE on the same InnoDB table could
result in deadlock. (Bug #71433, Bug #18110156)
• XA START after a server restart with the exising XID followed by XA COMMIT failed to commit. (Bug
#71352, Bug #18068253)
• Proxy users were unable to execute statements if the proxied user password had expired. (Bug
#71337, Bug #18057562)
• MySQL did not compile with Bison 3. (Bug #71250, Bug #18017820, Bug #18978946)
• Deadlock could occur if three threads simultaneously performed INSTALL PLUGIN, SHOW
VARIABLES, and mysql_change_user(). (Bug #71236, Bug #18008907, Bug #72870, Bug
#18903155)
• A statement of the following form broke row-based replication because it created a table having a
field of data type BIGINT with a display width of 3000, which is beyond the maximum acceptable
value of 255:
CREATE TABLE t1 AS SELECT REPEAT('A',1000) DIV 1 AS a;
(Bug #71179, Bug #17994219)
• When MySQL runs as service on Windows, NTService.Stop() initiates shutdown and exit events
during shutdown. After a code reorganization in MySQL 5.7.3, a call to clean_up() was missed,
resulting in initiation of crash recovery. (Bug #71104, Bug #17980260)
• If there was a predicate on a column referenced by MIN() or MAX() and that predicate was not
present in all the disjunctions on key parts earlier in the compound index, Loose Index Scan returned
an incorrect result. (Bug #71097, Bug #17909656)
• Invalid memory access could occur when using prepared statements if a mysql client connection
was lost after statement preparation was complete and there was at least one statement that was in
initialized state but not prepared yet. (Bug #70429, Bug #17512527)
213
MySQL 5.7 Release Notes
• Client auto-reconnect did not work for clients linked against libmysqlclient, even with
MYSQL_OPT_RECONNECT enabled.
Also, if a FEDERATED table was accessed after wait_timeout expired, a Lost connection to
MySQL server error occurred without an attempt to re-establish the connection. (Bug #70026, Bug
#17309863, Bug #14874, Bug #11745408)
• Full-text queries on MyISAM tables that included a LIMIT clause but no WHERE clause could return
too few rows. (Bug #69908, Bug #17261347)
• Updates could fail to update all applicable rows in cases where multiple key values were identical
except for trailing spaces. (Bug #69684, Bug #17156940)
• On Windows, REPAIR TABLE and OPTIMIZE TABLE failed for MyISAM tables with .MYD files larger
than 4GB. (Bug #69683, Bug #17235179)
• For logging of prepared statements to the general query log, the Execute line was logged after
statement execution, not before. (Bug #69453, Bug #16953758, Bug #20536590)
• Calls to UNCOMPRESS() produced Valgrind warnings during verification of the zip header of the
compressed data. (Bug #69202, Bug #18693654)
• mysql_tzinfo_to_sql mishandled some values from the abbreviation list (read from the
timezone information file) due to failure to account for the null character appended to the end of the
char array. (Bug #68861, Bug #16664462)
• Some statements could be written to the slow query log twice. (Bug #68626, Bug #16467055)
• File permissions and line endings of several test and configuration files were made more consistent
to avoid warnings from package checkers. (Bug #68521, Bug #16415173, Bug #16395459, Bug
#68517, Bug #16415032, Bug #71112, Bug #17919313, Bug #71113, Bug #17919422)
• In some cases, a successful CREATE VIEW could add invalid parentheses to expressions in the view
definition. (Bug #67791, Bug #15948263)
• If the general query log or slow query log file was set to a FIFO or socket file, and the file reader
went away, the server stopped executing statements. Now the server detects such files, logs an error
message, and continues with the appropriate log disabled. (Bug #67088, Bug #14757009)
• For non-debug builds of several client programs, the --help message did not correctly indicate that
the --debug, --debug-check, and --debug-info apply only for debug builds. (Bug #66854, Bug
#16272328)
• Notification of events for the general log were received by the audit log plugin only if the general
query log was enabled. Now notifications are posted regardless of whether the general query log is
enabled. (Bug #60782, Bug #12368204, Bug #20536590, Bug #75796, Bug #20479643)
• Queries that used GROUP BY INSERT() could produce spurious duplicate-key errors. (Bug #58081,
Bug #11765149)
• mysql_install_db could fail if not invoked in the MySQL installation base directory. (Bug #54034,
Bug #11761529)
• With big_tables enabled, queries that used COUNT(DISTINCT) on a simple join with a constant
equality condition on a non-duplicate key returned incorrect results. (Bug #52582, Bug #11760197)
References: See also: Bug #18853696.
• LOAD DATA LOCAL INFILE could use all CPU if import errors occurred when there were no line
delimiters. (Bug #51840, Bug #11759519)
• For an existing nondynamic (built-in) plugin, the error message for an attempted UNINSTALL
PLUGIN was misleading (the plugin does not exist). Now the message indicates that built-in plugins
cannot be uninstalled. (Bug #51771, Bug #11759453)
214
MySQL 5.7 Release Notes
• LIKE matches failed for code points of HALF WIDTH KATAKANA in the sjis and cp932 character
sets. (Bug #47641, Bug #11755818)
• The server failed to produce an error for INSERT statements that provided no column names but did
provide column values. (Bug #20943, Bug #11745889, Bug #18064775)
References: This issue is a regression of: Bug #16820562.
• Connection IDs are 32-bit unsigned integers, beginning at 1. When the server assigns connection
IDs and reaches the top of the 32-bit range, it rolls the value over to begin at 1 again. It was possible
that the server would assign a connection ID to a new thread while that ID was still in use by an
existing thread, if the old thread was particularly long running. For such cases, reference to the ID
becomes ambiguous. For example, it cannot reliably be determined for KILL connection_id
which thread to kill, which could lead to undefined behavior. This behavior has been corrected so
that in-use IDs are not reused.
Changes in MySQL 5.7.4 (2014-03-31, Milestone 14)
Note
This is a milestone release, for use at your own risk. Upgrades between
milestone releases (or from a milestone release to a GA release) are not
supported. Significant development changes take place in milestone releases
and you may encounter compatibility issues, such as data format changes that
require attention in addition to the usual procedure of running mysql_upgrade.
For example, you may find it necessary to dump your data with mysqldump
before the upgrade and reload it afterward.
In Memoriam
This release is dedicated to the memory of two young engineers of the MySQL Engineering family,
Astha and Akhila, whom we lost while they were in their early twenties. This is a small remembrance
and a way to recognize your contribution to the 5.7 release. You will be missed.
• Character Set Support
• Compilation Notes
• Performance Schema Notes
• Security Notes
• SQL Mode Notes
• Functionality Added or Changed
• Bugs Fixed
Character Set Support
• MySQL now includes a gb18030 character set that supports the China National Standard GB18030
character set. For more information about MySQL character set support, see Character Set Support.
Compilation Notes
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Performance Schema Notes
• Performance Schema performance was improved in the following ways:
215
MySQL 5.7 Release Notes
• When a thread connects, reset of all per-thread statistics is now delayed until a statistic is actually
collected. This lazy initialization benefits workloads with very short-lived sessions, for which
instrumentation is disabled.
• When a thread disconnects, the per-thread statistics are aggregated to a parent only for statistics
that actually collected data. This optimization benefits workloads with very short-lived sessions, for
which instrumentation is disabled.
• For statement instrumentation, reset of an individual EVENT_NAME statistic is also now delayed
until a statistic is actually collected. This benefits all workloads that contain only a few types of
statements (SELECT, INSERT, UPDATE, DELETE, and so forth) from the very large set statements
supported in MySQL. Only statements for event names actually executed are aggregated on
disconnect.
• The memory footprint of internal memory buffers is reduced, by removing some attributes
reserved for future use, that were in fact not used. In particular, statistics for mutexes, rwlocks and
conditions now need less memory.
The Performance Schema now instruments prepared statements (for both the binary and text
protocols):
• Information about prepared statements is available in the prepared_statements_instances
table. This table enables inspection of prepared statements used in the server and provides
aggregated statistics about them.
• The performance_schema_max_prepared_statements_instances system variable
controls the size of the table.
• The Performance_schema_prepared_statements_lost status variable indicates how many
prepared statements could not be instrumented.
For more information, see The prepared_statements_instances Table.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
References: See also: Bug #18324285.
Security Notes
• Incompatible Change: MySQL now enables database administrators to establish a policy for
automatic password expiration: Any user who connects to the server using an account for which the
password is past its permitted lifetime must change the password. The implementation has these
components:
• The default_password_lifetime system variable defines global password expiration
policy. A value of N greater than zero means that passwords have a lifetime of N days. A value
of 0 disables automatic password expiration. The default is 360; passwords must be changed
approximately once per year.
• The mysql.user table has new columns that store expiration policy information for individual
accounts:
• password_last_changed indicates when the password was last changed. The server uses
this column when clients connect to determine whether the password is past its lifetime and
must be changed per the expiration policy in effect.
• password_lifetime indicates the account password lifetime. A value of N greater than zero
means that the password has a lifetime of N days. 0 disables automatic password expiration.
NULL (the default) means that the global expiration policy applies.
216
MySQL 5.7 Release Notes
• The ALTER USER statement has new options to set password expiration policy for individual
accounts.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade
(and restart the server) to incorporate the changes to the mysql.user table. For each account,
mysql_upgrade uses the time at which it executes to set the password_last_changed column
and sets password_lifetime to NULL. This causes the default global expiration policy to go into
effect (passwords have a lifetime of 360 days).
For more information, see Password Management, and ALTER USER Syntax.
• Incompatible Change: MySQL deployments installed using mysql_install_db now are secure
by default. The following changes have been implemented as the default deployment characteristics:
• The installation process creates only a single root account, 'root'@'localhost',
automatically generates a random password for this account, and marks the password expired.
The MySQL administrator must connect as root using the random password and use SET
PASSWORD to select a new password. (The random password is found in the .mysql_secret file
in the home directory of the effective user running the script.)
• Installation creates no anonymous-user accounts.
• Installation creates no test database.
Those changes are implemented by modifying the default mode of operation for
mysql_install_db, which is invoked automatically during RPM installation operations. Therefore,
the changes also affect non-RPM installation methods for which you invoke mysql_install_db
manually.
Because mysql_install_db deployment now is secure by default, the --random-passwords
option is unnecessary and has been removed. It has been replaced by the --skip-randompasswords option. You can use this option to explicitly produce a deployment that is not secure by
default:
• No random password is generated for the 'root'@'localhost' account.
• A test database is created that is accessible by any user.
Note
mysql_install_db no longer creates anonymous-user accounts, even with
--skip-random-passwords.
The mysql_secure_installation program now has a --use-default option, which causes
the program to execute noninteractively. It can be used for unattended install operations.
SQL Mode Notes
• Incompatible Change
Note
The change described here to make ERROR_FOR_DIVISION_BY_ZERO,
NO_ZERO_DATE, and NO_ZERO_IN_DATE do nothing when named explicitly
and include them in strict mode was reverted in MySQL 5.7.8 (see Changes
in MySQL 5.7.8 (2015-08-03, Release Candidate)). The intent is still that they
be used in conjunction with strict mode, so a warning occurs as of 5.7.8 if
they are enabled without also enabling strict mode or vice versa.
217
MySQL 5.7 Release Notes
The ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE SQL modes
now are deprecated and do nothing when named explicitly. Instead, their effects are included in
the effects of strict SQL mode (STRICT_ALL_TABLES or STRICT_TRANS_TABLES). In other
words, strict mode now means the same thing as the previous meaning of strict mode plus the
ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE modes. This change
reduces the number of SQL modes with an effect dependent on strict mode and makes them part of
strict mode itself.
To prepare for the SQL mode changes in this version of MySQL, it is advisable before upgrading to
read SQL Mode Changes in MySQL 5.7. That discussion provides guidelines to assess whether your
applications will be affected by these changes.
The ERROR_FOR_DIVISION_BY_ZERO, NO_ZERO_DATE, and NO_ZERO_IN_DATE SQL mode
names are still recognized (so that statements that refer to them do not produce an error), but they
will be removed in a future MySQL release. To make advance preparation for versions of MySQL in
which these mode names do not exist, applications should be modified not to refer to them.
Functionality Added or Changed
• Incompatible Change: The AES_ENCRYPT() and AES_DECRYPT() functions now permit control of
the block encryption mode and take an optional initialization vector argument:
• The new block_encryption_mode system variable controls the mode for block-based
encryption algorithms. Its default value is aes-128-ecb, which signifies encryption using a key
length of 128 bits and ECB mode.
• An optional init_vector argument provides an initialization vector for encryption modes that
require it:
AES_ENCRYPT(str,key_str[,init_vector])
AES_DECRYPT(crypt_str,key_str[,init_vector])
• A random string of bytes to use for the initialization vector can be produced by calling the new
RANDOM_BYTES() function.
For more information, see Encryption and Compression Functions.
These changes make statements that use AES_ENCRYPT() or AES_DECRYPT() unsafe for
statement-based replication and they cannot be stored in the query cache. Queries that use
RANDOM_BYTES() are unsafe for statement-based replication and cannot be stored in the query
cache.
• Performance; InnoDB: InnoDB now supports multiple page_cleaner threads for flushing dirty
pages from buffer pool instances. A new system variable, innodb_page_cleaners, is used to
specify the number of page_cleaner threads. The default value of 1 maintains the pre-MySQL 5.7.4
configuration in which there is only a single page_cleaner thread. This enhancement builds on work
completed in MySQL 5.6.2, which introduced a single page cleaner thread to offload buffer pool
flushing work from the InnoDB master thread.
• InnoDB: InnoDB now supports the Transportable Tablespace feature for partitioned InnoDB tables
and individual InnoDB table partitions. This enhancement eases backup procedures for partitioned
tables and enables copying of partitioned tables and individual table partitions between MySQL
instances. For additional information, see Copying File-Per-Table Tablespaces to Another Instance.
(Bug #18121824, Bug #70196, Bug #18304194, Bug #71784)
• InnoDB: Parameters used to identify an InnoDB pages are replaced by two new classes, and fold
value and zip_size value calculations have been optimized. These changes simplify code by
reducing the number of page identifier parameters passed to functions. (Bug #18073495)
218
MySQL 5.7 Release Notes
• InnoDB: If system tablespace files (“ibdata files”) are located on Fusion-io devices that support
atomic writes, doublewrite buffering is automatically disabled and Fusion-io atomic writes are used
for all data files. Because the doublewrite buffer setting is global, doublewrite buffering is also
disabled for data files residing on non-Fusion-io hardware.
This feature is only supported on Fusion-io hardware and is only enabled for Fusion-io NVMFS on
Linux. To take full advantage of this feature, an innodb_flush_method setting of O_DIRECT is
recommended. (Bug #18069105)
• InnoDB: Reverse index leaf page scan has been optimized.
btr_pcur_restore_position_func() can now perform optimistic restoration for reverse
cursors, which reduces block->mutex contention on the root page, especially for concurrent
reverse scans. (Bug #17666170)
• InnoDB: A new system variable, innodb_log_write_ahead_size, allows you to configure the
write-ahead block size for redo logs to a value that matches the operating system or file system
cache block size in order to avoid “read-on-write” for redo log writes. Read-on-write occurs when
redo log blocks are not entirely cached to the operating system or file system due to a mismatch
between write-ahead block size for redo logs and operating system or file system cache block size.
Avoiding read-on-write improves throughput stability for redo log writes. (Bug #17571371)
• InnoDB: Online DDL support is extended to the following operations for regular and partitioned
InnoDB tables:
• OPTIMIZE TABLE
• ALTER TABLE ... FORCE
• ALTER TABLE ... ENGINE=INNODB (when run on an InnoDB table)
Online DDL support reduces table rebuild time and permits concurrent DML. See Online DDL
Overview.
(Bug #13975225)
• InnoDB: The innodb_use_sys_malloc and innodb_additional_mem_pool_size system
variables, which were deprecated in MySQL 5.6.3, are removed in MySQL 5.7.4.
• InnoDB: The InnoDB Tablespace Monitor and InnoDB Table Monitor were removed in MySQL
5.7.4. Table and tablespace metadata can be obtained from INFORMATION_SCHEMA tables.
• InnoDB: New global configuration parameters, innodb_status_output and
innodb_status_output_locks, allow you to dynamically enable and disable the standard
InnoDB Monitor and InnoDB Lock Monitor for periodic output. Previously, enabling and disabling
these monitors for periodic output required creating and dropping specially named tables
(innodb_monitor and innodb_lock_monitor). For additional information, see InnoDB Monitors.
• Replication: The binary log dump thread has been optimized by removing unnecessary reallocation
of the send buffer. Previously, memory was allocated then freed for every event sent to the slave,
even when this was not strictly necessary. Following this optimization, the MySQL Server can make
better use of hardware resources by having the dump thread employ adaptative memory allocation,
which can also result in less CPU usage. (Bug #11747349, Bug #31932, Bug #11752288, Bug
#43426, Bug #13727951)
• Replication: It is now possible in many cases to execute CHANGE MASTER TO without first issuing
STOP SLAVE. This capability is added by implementing the following changes in the behavior of the
CHANGE MASTER TO statement, which now depends only on whether the slave SQL thread or slave
I/O thread is stopped, as described here:
219
MySQL 5.7 Release Notes
• If the SQL thread is stopped, you can execute CHANGE MASTER TO using the RELAY_LOG_FILE,
RELAY_LOG_POS, and MASTER_DELAY options, even if the slave I/O thread is running. No other
options may be used with this statement when the I/O thread is running.
• If the I/O thread is stopped, you can execute CHANGE MASTER TO using any of the options for this
statement except RELAY_LOG_FILE, RELAY_LOG_POS, or MASTER_DELAY, even when the SQL
thread is running. These three options cannot be used when the I/O thread is running.
• Both the SQL thread and the I/O thread must be stopped before issuing CHANGE MASTER TO with
MASTER_AUTO_POSITION = 1.
If you are using statement-based replication and temporary tables, it is possible for a CHANGE
MASTER TO statement following a STOP SLAVE statement to leave behind temporary tables on
the slave. As part of this set of improvements, a warning is now issued whenever this occurs. You
can avoid this in such cases by making sure that Slave_open_temp_tables is equal to 0 prior to
executing these statements.
For more information, see CHANGE MASTER TO Syntax, and Switching Masters During Failover.
• Replication: Implemented separate threads for sending and receiving semisynchronous replication
acknowledgement signals, so that event streams and ACK streams can be sent and received
simultaneously. This should reduce many common delays and thus improve performance with
semisynchronous replication in a number of settings.
• Solaris: On Solaris, mysql_config --libs now includes -R/path/to/library so that
libraries can be found at runtime. (Bug #18235669)
• On Windows, NOMINMAX is set using the ADD_DEFINITIONS() CMake macro rather than in
config.h.cmake so that it is set even without including my_config.h. (Bug #18192896)
• CMake support for compiling MySQL with gcc on Solaris was improved. Binary distributions for
Solaris now are built using gcc rather than Sun Studio, to enable compilation of code not handled
by Sun Studio. The client programs and the client libraries except the embedded library are still built
using Sun Studio.
A consequence of this change is that on Solaris, mysql_config no longer provides arguments
for linking with the embedded library, since this is now built using gcc instead of Sun Studio. To
get linking arguments for the embedded library, use the alternative script mysql_server_config
instead. (Bug #18146422, Bug #17826757)
• The CHECK_FUNCTION_REPLACEMENT() CMake macro was removed from Windows.cmake and
replacement functions are set explicitly instead since the result of the check was already hard coded
in WindowsCache.cmake. (Bug #18116661)
• MySQL now compiles using Clang 3.4. (Bug #18047020)
• In MySQL 5.7.1, the MySQL test suite mysql-test-run.sh program was modified to start the
server with InnoDB rather than MyISAM as the default storage engine. All tests in the MySQL
test suite were modified to include a force_default_myisam.inc file. This had to be done
because most legacy test results were recorded with the MyISAM engine and failed with a
result difference if run with InnoDB. A project is underway to migrate these tests and remove
force_default_myisam.inc for tests that do not need MyISAM. In 5.7.4, the rpl and binlog
suites and parts of the main suite were migrated. (Bug #17902011)
• Performance Schema instrumentation was added to capture GTIDs for transaction events. (Bug
#17799147)
• Performance Schema overhead was reduced for the pfs_lock implementation and the uses of
atomic operations in general. (Bug #17766582)
220
MySQL 5.7 Release Notes
• CMake now aborts the configuration process on Windows if a Visual Studio version earlier than 2010
is used. (Bug #17730320)
• A new CMake option, WITH_MSAN, permits enabling MemorySanitizer for compilers that support it.
(Bug #17632319)
• Previously, ALTER TABLE in MySQL 5.6 could alter a table such that the result had temporal
columns in both 5.5 and 5.6 format. Now ALTER TABLE upgrades old temporal columns to 5.6
format for ADD COLUMN, CHANGE COLUMN, MODIFY COLUMN, ADD INDEX, and FORCE operations.
This conversion cannot be done using the INPLACE algorithm because the table must be rebuilt, so
specifying ALGORITHM=INPLACE in these cases results in an error. Specify ALGORITHM=COPY if
necessary.
When ALTER TABLE does produce a temporal-format conversion, it generates a message that can
be displayed with SHOW WARNINGS: TIME/TIMESTAMP/DATETIME columns of old format
have been upgraded to the new format. (Bug #17246318)
• The mysql_version.h file defines two new macros, LIBMYSQL_VERSION and
LIBMYSQL_VERSION_ID, that indicate the string and numeric forms of the client library version.
• In the client library included with MySQL Server distributions, these macros have the same
values as MYSQL_SERVER_VERSION and MYSQL_VERSION_ID. For example, in MySQL
5.7.4, MYSQL_SERVER_VERSION and LIBMYSQL_VERSION are "5.7.4-m14", and
MYSQL_VERSION_ID and LIBMYSQL_VERSION_ID are 50704.
• In the client library included with Connector/C distributions, MYSQL_SERVER_VERSION and
MYSQL_VERSION_ID have the values of the MySQL version on which the Connector/C
distribution is based, whereas LIBMYSQL_VERSION and LIBMYSQL_VERSION_ID indicate
the Connector/C version. For example, Connector/C 6.1.3 is based on MySQL 5.7.4, so
MYSQL_SERVER_VERSION and MYSQL_VERSION_ID have values of "5.7.4-m14" and 50704,
whereas LIBMYSQL_VERSION and LIBMYSQL_VERSION_ID have values of "6.1.3" and
60103.
In addition, the mysql_get_client_info() and mysql_get_client_version() C API
functions in the client library now return values that reflect the type of distribution that provides the
client library:
• In MySQL distributions, mysql_get_client_info() returns MYSQL_SERVER_VERSION and
mysql_get_client_version() returns MYSQL_VERSION_ID. This is the same as before.
• In Connector/C distributions, mysql_get_client_info() returns LIBMYSQL_VERSION and
mysql_get_client_version() returns LIBMYSQL_VERSION_ID. Previously, these functions
returned the MySQL version, the same as in MySQL distributions.
(Bug #17171724)
• Overhead was reduced for filesort comparison operations. (Bug #14635144)
• Based on community feedback, the default value of 10 for the eq_range_index_dive_limit
system variable has proven to be too low. The default has been raised to 200. (Bug #70586, Bug
#17587952)
• mysql_install_db provides a more informative diagnostic message when required Perl modules
are missing. (Bug #69844, Bug #18187451)
• CMake now supports a -DTMPDIR=dir_name option to specify the default tmpdir value. If
unspecified, the value defaults to P_tmpdir in <stdio.h>. Thanks to Honza Horak for the patch.
(Bug #68338, Bug #16316074)
• MySQL now supports server-side timeouts for execution of SELECT statements:
221
MySQL 5.7 Release Notes
• SELECT supports a MAX_STATEMENT_TIME option to specify a timeout for individual queries. For
example:
SELECT MAX_STATEMENT_TIME = 5000 id, name FROM my_table WHERE ...
The server terminates the statement if its execution exceeds the timeout value.
• The max_statement_time system variable specifies the timeout value for SELECT statements
executed within the session that include no MAX_STATEMENT_TIME option. If the value is 0,
timeouts are not enabled.
• The Max_statement_time_exceeded, Max_statement_time_set, and
Max_statement_time_set_failed status variables provide information about SELECT
statements affected by timeouts.
Timeout values are in milliseconds.
For more information, see SELECT Syntax, and Server System Variables.
Thanks to Davi Arnaut for the patch on which this feature is based. (Bug #68252, Bug #16271666)
• Overhead was reduced for metadata lock acquisition for DML statements. (Bug #58627, Bug
#11765641)
• Logarithmic functions return NULL if the argument is less than or equal to 0.0E0. They now also
report a warning “Invalid argument for logarithm”. (Bug #50507, Bug #11758319)
• Code instrumented with Valgrind did not preallocate memory in alloc_root(), to help find
bugs. This behavior is now also enabled if ASAN (address sanitizer) is used. (Bug #44582, Bug
#11753184)
• mysqlbug, an obsolete program for generating bug reports, has been removed from the source
code.
• The server can now report session-state changes to client programs. Reportable session state
consists of these values:
• The default schema (database)
• Session-specific values for system variables
• User-defined variables
• Temporary tables
• Prepared statements
The MySQL client/server protocol now includes tracker information so that session state changes
can be detected. One use for the tracker mechanism is that it provides a means for MySQL
Connectors, Fabric, and client applications to determine whether any session context is available to
ensure session migration from one server to another. (To change connections in a load-balanced
environment, it is necessary to detect whether there is session state to take into consideration when
deciding whether a switch can be made.)
The user interface to control the tracker and retrieve state-change information from it has the
following components, which enable implementation of state-change tracking on the client side:
• Clients can request notification when there is a change to any of the session state-related values
just listed, in the form of a flag that is set in the OK packet received from the server after the
222
MySQL 5.7 Release Notes
change occurs. To control notification, enable or disable the session_track_state_change
system variable. This variable is disabled by default.
• Clients can request notification of changed values for certain specific types of session state
information:
• The default schema name. To control notification, enable or disable the
session_track_schema system variable. This variable is enabled by default.
• The session values of system variables. Notification occurs for the system variables named by
the session_track_system_variables system variable. By default, notification is enabled
for time_zone, autocommit, character_set_client, character_set_results, and
character_set_connection. (The latter three variables are those affected by SET NAMES.)
• To enable applications to extract the state-change information returned by the server, the MySQL
C API includes a pair of functions:
• mysql_session_track_get_first() fetches the first state-change information received
from the server.
• mysql_session_track_get_next() fetches any remaining statechange information received from the server. Following a successful call to
mysql_session_track_get_first(), call this function repeatedly as long as it returns
success.
• Because there are new API functions, the client library ABI version is now 18.3. Shared library
names now include 18.3 where appropriate.
• The mysqltest program has enable_session_track_info and
disable_session_track_info commands to enable and disable tracking of session statechange information.
For more information, see Server System Variables and mysql_session_track_get_first(). For
information about the structure of the OK packet used to convey state-change information, see
OK_Packet.
• The metadata locking subsystem now uses a lock-free algorithm for acquiring and releasing locks
typical for DML statements. This gives better performance/scalability on multi-core machines in
workloads involving lots of small read-only transactions.
• The deprecated IGNORE clause for ALTER TABLE has been removed and its use produces an error.
• The metadata locking subsystem implementation now uses lock-free hashing rather than a hash
protected by a mutex. An implication of this change is that the metadata_locks_cache_size
and metadata_locks_hash_instances system variables no longer have any effect, so they are
deprecated and will be removed in a future MySQL release.
Bugs Fixed
• Incompatible Change: Old clients (older than MySQL 5.5.7) failed to parse authentication
data correctly if the server was started with the --default-authenticationplugin=sha256_password option.
Note
As a result of this bug fix, MySQL 5.6.16 clients cannot connect to a 5.6.17
server using an account that authenticates with the sha256_password
plugin, nor can 5.6.17 clients connect to a 5.6.16 server. Similarly, MySQL
5.7.3 clients cannot connect to a 5.7.4 server using an account that
authenticates with the sha256_password plugin.
223
MySQL 5.7 Release Notes
(Bug #17495562)
• Important Change; InnoDB; Partitioning: The FLUSH TABLES statement's FOR EXPORT option is
now supported for partitioned InnoDB tables. (Bug #16943907)
• InnoDB; Replication: Attempting to reset a replication slave while innodb_force_recovery
is greater than 0 would return a cryptic error message: ERROR(1030) HY000: Got error -1
from storage engine. The error message has been changed to: ERROR HY000: Operation
not allowed when innodb_force_recovery > 0. Replication options such as --relaylog-info-repository=TABLE and --master-info-repository=TABLE store information
in tables in InnoDB. When innodb_force_recovery is greater than 0, replication tables cannot
be updated which may cause replication administration commands to fail. (Bug #17287443, Bug
#69907)
• InnoDB; Replication: An INSERT ...ON DUPLICATE KEY UPDATE statement run on a table with
multiple unique indexes would sometimes cause events to be incorrectly written to the binary log.
(Bug #11758237, Bug #50413)
• InnoDB; Replication: Using the InnoDB memcached plugin (see InnoDB memcached Plugin) with
innodb_api_enable_binlog set to 1 caused the server to leak memory. (Bug #70757, Bug
#17675622)
• InnoDB; Microsoft Windows: TRUNCATE TABLE on Windows would report multiple 'chsize'
returned OS error 71 errors. (Bug #18176071, Bug #71173)
• InnoDB; Microsoft Windows: On Windows, a regression introduced in 5.7.3 would allow log
writes during sync operations, which should not be allowed due to an issue in some Windows
environments. (Bug #17824101)
• InnoDB; Solaris: The loader in some Solaris versions would refuse to start a GCC-compiled binary
(such as the mysqld binary) that uses the PAUSE assembler instruction. (Bug #18122171)
• InnoDB: A !sync_check_iterate(check) assertion occurred in fts_create_doc_id()
during an INSERT operation. (Bug #18253210)
• InnoDB: trx_undo_truncate_start would write to the redo log for temporary undo log
segments, resulting in a purge thread assertion. (Bug #18252937)
• InnoDB: Unused parameters and variables along with disabled functionality has been removed from
redo log code. This patch also includes redo log code improvements including test enablement,
addition of Valgrind instrumentation, and minor code refactoring. (Bug #18251675)
• InnoDB: The user defined type, xid_t, was defined multiple times. (Bug #18251254)
• InnoDB: Doublewrite buffer error messages referenced page numbers in an inconsistent manner.
(Bug #18242594)
• InnoDB: InnoDB would perform unnecessary redo log writes and flushing for temporary
tablespaces. (Bug #18236692)
• InnoDB: The truncate_t::drop_indexes and truncate_t::create_indexes methods
would disable redo logging when modifying the system tablespace. (Bug #18236000)
• InnoDB: For full-text queries, a failure to check that num_token is less than
max_proximity_item could result in an assertion. (Bug #18233051)
• InnoDB: An invalid memmove in fts_query_fetch_document would cause a serious error. (Bug
#18229433)
• InnoDB: InnoDB would write to the redo log for some operations on temporary tablespaces. (Bug
#18226934)
224
MySQL 5.7 Release Notes
• InnoDB: log_mutex_exit should be called before log_buffer_extend when the log buffer
mutex is held. (Bug #18202904)
• InnoDB: The GCC 4.4 compiler would emit a bogus warnings about InnoDB parsing functions,
indicating that output is uninitialized. (Bug #18192536)
• InnoDB: To simplify code and reduce memory usage, InnoDB redo log scan records for file-level
operations, previously stored in a hash table, are now processed immediately. (Bug #18180875)
• InnoDB: innodb_ft_result_cache_limit now has a hardcoded maximum value of
4294967295 bytes or (2**32 -1). The maximum value was previously defined as the maximum value
of ulong. (Bug #18180057, Bug #71554)
• InnoDB: An UPDATE resulted in a memory access error in lock_rec_other_trx_holds_expl.
The transaction list (trx_sys->rw_trx_list) was traversed without acquiring the transaction
subsystem mutex (trx_sys->mutex). (Bug #18161853)
• InnoDB: InnoDB failed to restore a corrupt first page of a system tablespace data file from the
doublewrite buffer, resulting in a startup failure. (Bug #18144349, Bug #18058884)
• InnoDB: Temporary tablespace file size did not match the file size specified by --innodb-tempdata-file-path due to an error in file size allocation logic. (Bug #18141070)
• InnoDB: A regression introduced by Bug #14329288 would result in a performance degradation
when a compressed table does not fit into memory. (Bug #18124788, Bug #71436)
References: This issue is a regression of: Bug #14329288.
• InnoDB: The maximum value for innodb_thread_sleep_delay is now 1000000
microseconds. The previous maximum value (4294967295 microseconds on 32-bit and
18446744073709551615 microseconds on 64-bit) was unnecessarily large. Because
the maximum value of innodb_thread_sleep_delay is limited by the value set for
innodb_adaptive_max_sleep_delay (when set to a non-zero value), the maximum
value for innodb_thread_sleep_delay is now the same as the maximum value for
innodb_adaptive_max_sleep_delay. (Bug #18117322)
• InnoDB: The fil_node_create function would perform an unnecessary hash table lookup. (Bug
#18116588)
• InnoDB: INFORMATION_SCHEMA.INNODB_TRX contained a bogus transaction ID that did not
match transaction ID values printed elsewhere. The method used to retrieve transaction IDs was
inconsistent. (Bug #18111007)
• InnoDB: When starting the server, unnecessary “checking space” log messages would be printed
when processing the doublewrite buffer. (Bug #18101380)
• InnoDB: A compiler error (unable to find string literal operator) was returned when
building in c++11 mode. (Bug #18082139)
• InnoDB: The UNIV_LOG_DEBUG debug flag, which is no longer fully functional, has been removed.
(Bug #18080537)
• InnoDB: In the case of a corrupted clustered index on a temporary table, the server would crash
on an INSERT instead of returning an error. In the case of a corrupted clustered index on a normal
table, an error was not returned and the INSERT would succeed. (Bug #18064548)
• InnoDB: Specifying an alternate directory for InnoDB tables using datadir and then moving .ibd
files to the default MySQL data directory would result in a serious error when attempting a DROP
TABLE operation. (Bug #18063570)
• InnoDB: Attempting to uninstall the InnoDB memcached plugin while the InnoDB memcached
plugin is still initializing would kill the InnoDB memcached daemon thread. Uninstall should wait until
initialization is complete. (Bug #18038948)
225
MySQL 5.7 Release Notes
• InnoDB: A full-text tokenizer thread would terminate with an incorrect error message. (Bug
#18021306)
• InnoDB: In debug builds, creating a unique index on a binary column, with input data containing
duplicate keys, would cause an assertion. (Bug #18010711)
• InnoDB: The srv_monitor_thread would crash in the lock_print_info_summary() function
due to a race condition between the srv_monitor_thread and purge coordinator thread. (Bug
#17980590, Bug #70430)
• InnoDB: A boolean mode full-text search query would result in a memory access violation during
parsing. (Bug #17978763)
• InnoDB: Logging functions were not used consistently. The bug fix replaces occurrences of
fprintf(stderr, message) and fputs() with ib_logf(). Also, because ib_logf()
emits a timestamp with each message, the bug fix removes unnecessary occurrences of
ut_print_timestamp(). (Bug #17935793, Bug #17534737)
• InnoDB: Due to a parser error, full-text search queries that include a sub-expression could return the
wrong result. (Bug #17840768)
• InnoDB: The innochecksum tool did not use a Windows-specific API to retrieve file size
information, which resulted in an incorrect error message (Error: ibdata1 cannot be found)
when the MySQL 5.6 innochecksum 2GB file size limit was exceeded. innochecksum now
provides support for files larger than 2GB in both MySQL 5.6 and MySQL 5.7. (Bug #17810862, Bug
#70936)
• InnoDB: Due to a regression introduced by the fix for Bug#17371537, memory was not allocated for
the default memcached engine when using the default memcached engine as the backstore for data
instead of InnoDB. (Bug #17800829)
• InnoDB: A page allocation for an undo log due failed with a “table is full” error message instead of an
“undo log is full” error message. (Bug #17779822)
• InnoDB: If a crash occurred while temporary tables are active, InnoDB would report an invalid error
message on restart indicating that a temporary table does not exist in the InnoDB internal data
dictionary. (Bug #17779729)
• InnoDB: ut_free could be called more than once in succession. (Bug #17763472)
• InnoDB: An index tree modification could result in a deadlock. (Bug #17754767)
• InnoDB: A race condition in DebugPolicy::enter() would cause a segmentation fault in
sync_array_cell_print. (Bug #17713784)
• InnoDB: Manipulating a table after discarding its tablespace using ALTER TABLE ... DISCARD
TABLESPACE could result in a serious error. (Bug #17700280)
• InnoDB: Persistent optimizer statistics would cause stalls due to latch contention. (Bug #17699331,
Bug #70768)
• InnoDB: Attempting to add an invalid foreign key when foreign key checking is disabled
(foreign_key_checks=0) would cause a serious error. (Bug #17666774)
• InnoDB: For debug builds, the table rebuilding variant of online ALTER TABLE, when run on tables
with BLOB columns, would cause an assertion in the row_log_table_apply_update function.
For normal builds, a DB_PRODUCTION error would be returned. (Bug #17661919)
• InnoDB: An InnoDB full-text search failure would occur due to an “unended” token. The string and
string length should be passed for string comparison. (Bug #17659310)
• InnoDB: MATCH() ... AGAINST queries that use a long string as an argument for AGAINST()
could result in an error when run on an InnoDB table with a full-text search index. (Bug #17640261)
226
MySQL 5.7 Release Notes
• InnoDB: Databases names beginning with a digit or special character would cause a full-text search
(FTS) parser error. (Bug #17607687)
References: See also: Bug #17607956.
• InnoDB: Under certain conditions, a regression introduced by the fix for Bug #11758237 would
cause an assertion error when INSERT ... ON DUPLICATE KEY UPDATE or REPLACE
statements encounter a DB_DUPLICATE_KEY error. (Bug #17604730)
References: This issue is a regression of: Bug #11758237.
• InnoDB: In debug builds, a merge insert buffer during a page read would cause a memory access
violation. (Bug #17561188)
• InnoDB: The patch for Bug #16852278, which simplifies and optimizes comparison functions in
InnoDB, caused a query performance regression. (Bug #17543588)
References: See also: Bug #16852278.
• InnoDB: In sync0rw.ic, rw_lock_x_lock_func_nowait would needlessly call
os_thread_get_curr_id. (Bug #17509710, Bug #70417)
• InnoDB: Truncating a memcached InnoDB table while memcached is performing DML operations
would result in a serious error. (Bug #17468031)
• InnoDB: The server could fail to restart if a crash occurred immediately following a RENAME TABLE
in an ALTER TABLE, RENAME TABLE sequence. (Bug #17463290)
• InnoDB: If a tablespace data file path is updated in a .isl file and then a crash recovery is
performed, the updated tablespace data file path is read from the .isl file but the SYS_DATAFILES
table would not be not updated. The SYS_DATAFILES table is now updated with the new data file
path after crash recovery. (Bug #17448389)
• InnoDB: Attempting to rename a table to a missing database would result in a serious error. (Bug
#17447500)
• InnoDB: If the first page (page 0) of file-per-table tablespace data file was corrupt, recovery would
be halted even though the doublewrite buffer contained a clean copy of the page. (Bug #17335427,
Bug #70087, Bug #17341780)
• InnoDB: The InnoDB memcached Readme file (README-innodb_memcached) incorrectly stated
that libevent 1.6.0 is linked statically into daemon memcached. The bundled version of libevent is
1.4.12, not 1.6.0. (Bug #17324419, Bug #70034)
• InnoDB: When creating a table there are a minimum of three separate inserts on the
mysql.innodb_index_stats table. To improve CREATE TABLE performance, there is now a
single COMMIT operation instead of one for each insert. (Bug #17323202, Bug #70063)
• InnoDB: The server would halt with an assertion in lock_rec_has_to_wait_in_queue(lock)
due to a locking-related issue and a transaction being prematurely removed from trx_sys>rw_trx_set. (Bug #17320977)
• InnoDB: The ALTER TABLE INPLACE algorithm failed to decrease the auto-increment value. (Bug
#17250787, Bug #69882)
• InnoDB: Comments in btr0cur.cc incorrectly stated that btr_cur_pessimistic_update()
and btr_cur_optimistic_update() would accept a NULL value. (Bug #17231743, Bug
#69847)
• InnoDB: dict_table_schema_check would call dtype_sql_name needlessly. (Bug #17193801,
Bug #69802)
227
MySQL 5.7 Release Notes
• InnoDB: fil_check_first_page() failed to check if fsp_flags_get_zip_size() returned a
valid value, which resulted in a segmentation fault when starting mysqld. (Bug #17033182)
• InnoDB: The function os_file_get_status would not work with raw devices. (Bug #17023438,
Bug #69424)
• InnoDB: The lock_rec_other_has_expl_req function in lock0lock.cc would perform
unnecessary work. (Bug #17016214, Bug #69576)
• InnoDB: Valgrind would report uninitialized values while running a rollback debug test. The Valgrind
warnings should only appear in Valgrind-instrumented builds. (Bug #16969876)
• InnoDB: During crash recovery, an incorrect transaction active time would result in rolling back an
uncommitted transaction. (Bug #16936961, Bug #69438)
• InnoDB: Heap block debugging information (file_name, lineno), used for logging diagnostics,
would appear in release builds. This information should only appear in debug builds. (Bug
#16924719, Bug #69422)
• InnoDB: An online ALTER TABLE operation would consume more memory than expected. During
an online ALTER TABLE operation, an online log buffer containing a head and tail buffer is created
for each index that is created or rebuilt. The tail buffer is the writer context and is only required for
concurrent write operations on an index while the ALTER TABLE operation is in progress. The head
buffer is the reader context and is only required during the log apply phase. To reduce memory
consumption, the tail buffer is now allocated when the first DML statement is run on the index, and
the head buffer is only allocated in the log apply phase and freed afterwards. (Bug #16868967, Bug
#69325, Bug #17911720)
• InnoDB: Renaming a column while also adding or dropping columns in the same ALTER TABLE
operation would cause an error. (Bug #16864981)
• InnoDB: A type name (srv_shutdown_state) was the same as a variable name. The
srv_shutdown_state type name has been changed to srv_shutdown_t. (Bug #16735398)
• InnoDB: The buf_buddy_relocate function would perform an unnecessary hash lookup. (Bug
#16596057)
• InnoDB: On Windows, the full-text search (FTS) object ID was not in the expected hexadecimal
format. (Bug #16559254)
References: See also: Bug #16559119.
• InnoDB: Server shutdown would result in a hang with the following message written to the error log:
“[NOTE] InnoDB: Waiting for purge thread to be suspended.” (Bug #16495065)
• InnoDB: InnoDB failed to start when innodb_data_file_path specified the data file size in
kilobytes by appending K to the size value. (Bug #16287752)
• InnoDB: Fetching and releasing pages from the buffer pool and tracking the page state are
expensive and complex operations. Prior to the bug fix, these operations were performed using a
page mutex. Using a page mutex to track several things is expensive and does not scale well. The
bug fix separates fetch and release tracking (in-use state) of a page from page I/O state tracking.
Fetch and release is now tracked using atomics where available.
For portability, a new CMake build option, INNODB_PAGE_ATOMIC_REF_COUNT (default ON), can be
used to disable atomic page reference counting on platforms where atomics support is not available.
When atomic page reference counting is enabled (default), “[Note] InnoDB: Using atomics
to ref count buffer pool pages” is printed to the error log at server startup. If atomic page
reference counting is disabled, “[Note] InnoDB: Using mutexes to ref count buffer
pool pages” is printed instead. (Bug #16249481, Bug #68079)
• InnoDB: An insert buffer merge would cause an assertion error due to incorrectly handled ownership
information for externally stored BLOBs.
228
MySQL 5.7 Release Notes
InnoDB: Assertion failure in thread thread_num in file ibuf0ibuf.cc line 4080
InnoDB: Failing assertion: rec_get_deleted_flag(rec, page_is_comp(page))
(Bug #14668683)
• InnoDB: Decreasing the auto_increment_increment value would have no affect on the next
auto-increment value. (Bug #14049391, Bug #65225)
• InnoDB: Table renaming errors would appear in the LATEST FOREIGN KEY ERROR section of the
SHOW ENGINE INNODB STATUS output. (Bug #12762390, Bug #61746)
• InnoDB: The page latching algorithm for B-trees would lock sibling leaf pages, prolonging dictionary
locks. The bug fix implements prefetching of sibling leaf pages to reduce index lock holding time.
(Bug #12734249, Bug #61736)
• InnoDB: BUF_READ_AHEAD_AREA would frequently call ut_2_power_up for workloads with a
high I/O rate. The calculation is now performed once and the result is stored in the buf_pool_t
structure. (Bug #11762242, Bug #54814)
• InnoDB: UNIV_SYNC_DEBUG, which was disabled in univ.i with the fix for Bug#16720368, is now
enabled. (Bug #69617, Bug #17033591)
• Partitioning: Queries using the index_merge optimization (see Index Merge Optimization) could
return invalid results when run against tables that were partitioned by HASH. (Bug #17588348, Bug
#70588)
References: See also: Bug #16862316, Bug #17648468, Bug #18167648.
• Partitioning: When no partition had returned a row since the last HA_ERR_KEY_NOT_FOUND error,
the use of uninitialized memory in the priority queue used for returning rows in sorted order could
lead to a crash of the server. (Bug #17401628)
• Replication: When running the server with --gtid-mode=ON, STOP SLAVE followed
by START SLAVE resulted in a mismatch between the information provided by
INFORMATION_SCHEMA.INNODB_TEMP_TABLE_INFO and the Slave_open_temp_tables
status variable: the INNODB_TEMP_TABLE_INFO table showed that no temporary tables existed, but
Slave_open_temp_tables had a nonzero value. (Bug #18236612)
• Replication: Attempting to use semisynchronous replication concurrently with SSH connections
caused the server to fail. (Bug #18219471)
• Replication: When MASTER_HEARTBEAT_PERIOD was not included in CHANGE
MASTER TO, the statement reset Slave_heartbeat_period to its default value and
Slave_received_heartbeats to 0. Now the heartbeat period is not changed by CHANGE
MASTER TO unless explicitly set using MASTER_HEARTBEAT_PERIOD. In addition, the statement no
longer resets Slave_received_heartbeats. (Bug #18185490)
• Replication: After setting MASTER_SSL_CRLPATH using a CHANGE MASTER TO
statement, the option value was not displayed properly in the SSL_CRL_PATH column of the
replication_connection_configuration Performance Schema table. (Bug #18174719)
• Replication: The MASTER_SSL_CRL and MASTER_SSL_CRLPATH options are not available when
using yaSSL; MySQL Replication now sets these to NULL automatically whenever yaSSL is enabled.
(Bug #18165937)
• Replication: mysqlbinlog did not free up memory used by its event buffer when using the -rewrite-db option. (Bug #18164998)
• Replication: Setting --slave-parallel-workers to 1 or greater and starting the slave caused
the slave SQL thread to use but not release memory until the slave was restarted with STOP SLAVE
and START SLAVE. (Bug #18001777, Bug #71197)
229
MySQL 5.7 Release Notes
• Replication: When a slave was configured with replication filters and --log-warnings=2, every
statement which was filtered caused an entry to be written in the error log. For busy servers which
generated many statements to be filtered, the result was that the error log could quickly grow to
many gigabytes in size. Now a throttle is used for such errors, so that an error message is printed
only once in a given interval, saying that this particular error occurred a specific number of times
during that interval. (Bug #17986385)
• Replication: When the binary log I/O cache grew to exactly 32768 bytes and the current transaction
was preceded by a transaction whose size was greater than 32768 bytes, events could be corrupted
when written into the binary log. (Bug #17842137)
• Replication: When the master and the slave both had gtid_mode=ON set initially, and the slave
SQL thread was stopped while there remained GTID transactions in the relay log, if the slave
was then restarted with gtid_mode=OFF, then the slave SQL thread executed any anonymous
transaction it encountered without writing its GTID to the binary log, with the result that the GTID was
lost. This could cause problems when the slave was later promoted to a master, as the transaction
would be played again on the promoted master's slaves, leading quickly to inconsistencies on those
slaves. (Bug #17827018)
References: See also: Bug #17813449.
• Replication: When the master and the slave both had gtid_mode=OFF set initially, and the slave
SQL thread was stopped while there remained anonymous transactions in the relay log, if the slave
was then restarted with gtid_mode=ON, then the slave assigned GTIDs such transactions. This
could cause problems when the slave was later promoted to a master, as the transactions would be
played again on the promoted master's slaves, leading quickly to inconsistencies on those slaves.
(Bug #17813449)
References: See also: Bug #17827018.
• Replication: Creating and dropping large numbers of temporary tables could lead to increased
memory consumption. (Bug #17806014)
• Replication: SHOW SLAVE STATUS used incorrect values when reporting MASTER_SSL_CRL and
MASTER_SSL_CRLPATH. (Bug #17772911, Bug #70866)
References: This issue is a regression of: Bug #11747191.
• Replication: When log_warnings is greater than 1, the master prints binary log dump thread
information—containing the slave server ID, binary log file name, and binary log position—in
mysqld.1.err. A slave server ID greater than 2 billion was printed with a negative value in such
cases. (Bug #17641586, Bug #70685)
• Replication: mysqlbinlog --verbose failed when it encountered a corrupt row event in the
binary log. Such a row event could also cause the slave to fail. (Bug #17632978)
References: See also: Bug #16960133.
• Replication: Binary log events could be sent to slaves before they were flushed to disk on the
master, even when sync_binlog was set to 1. This could lead to either of those of the following
two issues when the master was restarted following a crash of the operating system:
• Replication cannot continue because one or more slaves are requesting replicate events that do
not exist on the master.
• Data exists on one or more slaves, but not on the master.
Such problems are expected on less durable settings (sync_binlog not equal to 1), but it should
not happen when sync_binlog is 1. To fix this issue, a lock (LOCK_log) is now held during
synchronization, and is released only after the binary events are actually written to disk. (Bug
#17632285, Bug #70669)
230
MySQL 5.7 Release Notes
• Replication: When running the slave with --slave-parallel-workers at 1 or greater, setting
--slave-skip-errors=all caused the error log to be filled with instances of the warning Slave
SQL: Could not execute Query event. Detailed error: ;, Error_code: 0. (Bug
#17581990, Bug #68429)
References: See also: Bug #17986385.
• Replication: When semi-synchronous replication was configured on an independent server with
no slaves and rpl_semi_sync_master_wait_no_slave was set to OFF, the master still waited
for an ACK from the slave. When rpl_semi_sync_master_wait_no_slave is set to OFF,
the master should revert to normal replication when the number of slaves reaches zero during
the specified timeout period. Now in such cases the server checks whether semi-synchronous
replication is switched on, and, if so, goes on to check whether any slaves are connected. If none are
connected, semi-synchronous replication is disabled until such time that the user sets the value of
rpl_semi_sync_master_wait_no_slave to ON. (Bug #17510411, Bug #70360)
• Replication: A number of possible state messages used as values for the PROCESSLIST_STATE
column of the threads Performance Schema table were longer than the width of the column (64
characters).
The long state messages have now been rewritten, and shortened accordingly. This fix applies in
MySQL 5.7 and later. (Bug #17319380)
• Replication: Seconds_Behind_Master in the output of SHOW SLAVE STATUS could under some
conditions be reported as 0 when it should have had a value greater than zero. (Bug #17233214)
References: See also: Bug #16579028.
• Replication: The server did not handle correctly the insertion of a row larger than 4 GB when using
row-based replication. (Bug #17081415)
• Replication: When using row-based replication, an additional auto-increment column on the slave
version of a table was not updated correctly; a zero was inserted instead. (Bug #17066269, Bug
#69680)
• Replication: Statements involving the Performance Schema tables should not be written to
the binary log, because the content of these tables is applicable only to a given MySQL Server
instance, and may differ greatly between different servers in a replication topology. The database
administrator should be able to configure (INSERT, UPDATE, or DELETE) or flush (TRUNCATE
TABLE) performance schema tables on a single server without affecting others. However, when
replicating from a MySQL 5.5 master to a MySQL 5.5 or later slave, warnings about unsafe
statements updating Performance Schema tables were elevated to errors. For MySQL 5.6 and later
slaves, this prevented the simultaneous use of performance_schema and GTIDs (see Replication
with Global Transaction Identifiers).
This fix causes all updates on tables in the performance_schema database to be filtered on
the master and not replicated, regardless of the type of logging that is in effect. Prior to this fix,
statements using were handled by being marked as unsafe for replication, which caused warnings
during execution; the statements were nonetheless written to the binary log, regardless of the logging
format in effect.
Existing replication behavior for tables in the INFORMATION_SCHEMA database is not changed by
this fix.
For more information, see MySQL Performance Schema. (Bug #16814264)
References: See also: Bug #14741537, Bug #18259193.
• Replication: Invalid event offsets in the binary log were not always handled correctly, which could
lead to replication failure. (Bug #16736412, Bug #69087)
231
MySQL 5.7 Release Notes
• Replication: The semisynchronous replication plugin was called twice for a DDL statement,
incrementing Rpl_semi_sync_master_yes_tx by 2 instead of 1 each time such a statement was
executed. (Bug #70410, Bug #17509011)
• Replication: Semisynchronous replication became very slow if there were many dump threads (such
as from mysqlbinlog or slave I/O connections) working at the same time. It was also found that
semisynchronous master plugin functions were called even when the dump connections did not
support semisynchronous replication, which led to locking of the plugin lock as well as wasting time
on necessary code.
After this fix, non-semisynchronous dump threads no longer call semisynchronous master functions
to observe binary events. (Bug #70218, Bug #17434690)
• Microsoft Windows: On Microsoft Windows, the rw-lock backup implementation for the
my_atomic_* functions was always used. Now, the native Microsoft Windows implementation is
used, where available. (Bug #18054042)
• Microsoft Windows: On Windows, the --local-service server option did not work, and was not
displayed in the --help message. (Bug #69637, Bug #17049656)
• Solaris: MySQL distributions for Solaris now include a source tarball for gcc under the share
directory, to comply with GPL conditions resulting from inclusion of the C++ runtime library. (Bug
#18306484)
• During compilation, attempts to create sql_yacc.h could be made from multiple directories
simultaneously. (Bug #18319335)
• mysql_secure_installation attempted to free memory incorrectly and exited abnormally after
a failed attempt to read an option file. (Bug #18255657)
• While printing the server version, the mysql client did not check for buffer overflow in a string
variable. (Bug #18186103)
• mysql_secure_installation exited if mysql_install_db had been run with the --skiprandom-passwords option. (Bug #18181665)
• Compilation failed if MySQL was configured with CFLAGS set to include a -Werror option with an
argument. (Bug #18173037)
• When the optimizer attempted to use MRR or DS-MRR to read an internally created temporary table,
the server could exit or raise an assertion. (Bug #18172819)
• The default compiler flags are picked up from cmake/build_configurations/
compiler_options.cmake. This can be switched off by the CMake DWITH_DEFAULT_COMPILER_OPTIONS=0 option. However, it could also be switched off for the C
or C++ compilers if the CFLAGS or CXXFLAGS environment variables were set.
Those environment variables now have no such effect. To specify compiler flags, use DWITH_DEFAULT_COMPILER_OPTIONS=0 option, or the -DCMAKE_C_FLAGS=flags and DCMAKE_C_FLAGS=flags options can be used. (Bug #18158812)
• A bug in the range optimizer code that handles index merge could lead to a server exit or missing
rows in the result set. (Bug #18136628)
• A shared libmysqld embedded server library was not built on Linux. A new
WITH_EMBEDDED_SHARED_LIBRARY CMake option now makes this possible. (Bug #18123048, Bug
#16430656, Bug #68559)
• Type casting during LIKE pattern match operations could cause a server exit. (Bug #18114294)
• mysql_config improperly produced nonempty output when invoked with the --libmysqld-libs
(or a synonym) if MySQL was configured with the WITHOUT_SERVER option. (Bug #18102839)
232
MySQL 5.7 Release Notes
• Repeated rebuilds in the same source tree resulted in libmysqld.a increasing in size each time.
(Bug #18082702)
• SHOW GRANTS could be used to view the password hash for a proxied user. Password hash display
now requires the SUPER privilege. (Bug #18057514)
• Building MySQL from source on Windows using Visual Studio 2008 failed with an identifier not
found error due to a regression introduced by the patch for Bug#16249481. (Bug #18057449)
References: This issue is a regression of: Bug #16249481.
• When tables are reopened from the table cache and the current thread is not instrumented for
the Performance Schema, the server exited attempting to populate OWNER_THREAD_ID in the
table_handles table. (Bug #18047865)
• Link failures were fixed on Solaris SPARC and Linux 64-bit platforms. (Bug #18004599)
• A memory leak occurred within the Performance Schema during server startup. (Bug #18003651)
• Building libevent was incorrectly dependent on MySQL being configured with the DWITH_INNODB_MEMCACHED=1 option. (Bug #17964544)
• During shutdown, a mutex that was still locked could be removed, causing a server exit. (Bug
#17959898)
• Compilation used different warning flags for Clang and GCC, producing different warning output
depending on which compiler you use. Warning output is now consistent for the two compilers. (Bug
#17959689)
• On Solaris, configuration failed if no STL_LIBRARY_NAME was found. (Bug #17954277)
• storage/ndb/CMakeLists.txt reset the CMake cache for some compiler flags for which the
result should have been saved. (Bug #17949504)
• The SUM_SORT_MERGE_PASSES column value in the
events_statements_summary_by_digest Performance Schema table was calculated
incorrectly. (Bug #17938255)
• If the events_statements_summary_by_digest Performance Schema table was full when a
statement with a new digest was found, the Performance_schema_digest_lost status variable
was not incremented. (Bug #17935314)
• The audit log plugin could cause a server exit during log file rotation operations when there were
many operations happening for multiple connections. (Bug #17930339)
• DECIMAL NOT NULL items could return NULL in subqueries. (Bug #17921777)
• FORCE INDEX [FOR ORDER BY] (index_name) did not work for joins.
The fix for this bug also changes the warning created for EXPLAIN. Instead of printing only
{IGNORE|USE|FORCE} INDEX it now also prints FOR {GROUP BY|ORDER BY|JOIN} if that was
specified in the query. (Bug #17889511)
• mysql_secure_installation exited if it connected using SSL and the user had an expired
password. (Bug #17880395)
• Shutdown of open connection threads could fail to occur cleanly during server shutdown. (Bug
#17863690)
• For debug builds, inserts into a multiple-table view could raise an assertion. (Bug #17834434)
• The optimizer could push down a condition when the index did not have the key part present in the
condition. (Bug #17814492)
233
MySQL 5.7 Release Notes
• With the compressed client/server protocol enabled, Performance Schema statement
instrumentation could raise an assertion. (Bug #17794846)
• The resetconnection command for mysql did not report proper errors if the server was down or
the user password had expired. (Bug #17772561)
• Contraction information in a collation could be mishandled, resulting in incorrect decisions about
whether a character is part of a contraction, and miscalculation of contraction weights. (Bug
#17760379)
• An assertion could be raised if a filesort failed to resize its main buffer when record properties
changed. (Bug #17757914)
• Valgrind errors were produced during row comparator setup. (Bug #17755540)
• The patch for Bug #16041903 introduced an incorrect DBUG_ASSERT that in debug builds raised a
spurious assertion. (Bug #17746721)
References: This issue is a regression of: Bug #16041903.
• Build and execution problems were fixed for builds made with gcc 4.8.1 in 32-bit mode on SPARC.
(Bug #17740390)
• Compilation failed if MySQL was configured using -DWITH_LIBWRAP=1. (Bug #17738805)
• For debug builds, the filesort algorithm could raise a spurious assertion. (Bug #17734642)
• The mysql_get_option symbol was missing from libmysql.dll. (Bug #17733103)
• In some cases, UNIX_TIMESTAMP() could return NULL when it should return 0. (Bug #17728371)
• The server could exit when executing an INSERT ... SELECT with UNION, ROLLUP, and ON
DUPLICATE KEY UPDATE with a subquery. (Bug #17727506)
References: This issue is a regression of: Bug #16967281.
• The cache used for the Index Merge access method was freed only after successful retrieval of all
rows. Interruption or failure of the operation led to a file descriptor leak. (Bug #17708621)
• The optimizer calculated the cost for joined buffer scans incorrectly, evaluating rows filtered out by
attached conditions not once, but once per join buffer. (Bug #17694707)
• Using the mysqldump --set-gtid-purged option with no value caused mysqldump to crash.
(Bug #17650245)
• If SAFE_MUTEX was enabled (true only for debug builds), THR_LOCK_mutex was used before being
initialized. (Bug #17641055, Bug #70639)
• A race condition between Performance Schema statement event threads led to a server exit. (Bug
#17637970)
• Incorrect reference counting in the range optimizer module resulted in potential for missing or
duplicate rows in the query result set. (Bug #17619119)
• For debug builds, an aggregate function in a subquery join condition could raise an assertion. (Bug
#17602807)
• After the fix for Bug #16409270, it was not possible to #include <mysql.h> following #include
<windows.h>. (Bug #17514554)
References: See also: Bug #16409270.
• An addressing error in accessing the join buffer could produce invalid results or a server exit. (Bug
#17513341)
234
MySQL 5.7 Release Notes
• The parser permitted some queries with multiple ORDER BY clauses, which then failed during
execution and caused a server exit. (Bug #17473479)
• For debug builds, the server could exit for statements that inserted into a BLOB column declared as
NOT NULL using a subquery that retrieved from a BLOB column and included GROUP BY NULL.
(Bug #17458917)
• Within a CASE expression, use of a subquery referencing the VALUES() function could cause a
server exit. (Bug #17458914)
References: This issue is a regression of: Bug #14789787.
• SET PASSWORD combined with assignment of a variable from a subquery result could raise an
assertion. (Bug #17458750)
• Insufficient cleanup after removal of a SELECT_LEX structure caused dereferencing of a NULL
pointer and a server exit. (Bug #17458169)
• The parser silently accepted duplicate ORDER BY clauses and/or LIMIT clauses before ORDER BY
clauses in subqueries. These caused failures during query execution. Fixing this problem results in
some changes in parser behavior. The parser no longer accepts:
• A LIMIT clause before an ORDER BY clause
• A LIMIT clause in a parentheses-less SELECT statement before a UNION keyword
• An INTO clause after a PROCEDURE ANALYSE() clause
(Bug #17426017, Bug #17703542, Bug #17727401)
• On Windows, mysql_secure_installation exited if the root password was expired. (Bug
#17415203)
• mysql_config incorrectly included some flags to generate compiler warning output. (Bug
#17400967)
• With semi-join optimization enabled, queries with nested subqueries could cause a server exit due to
incorrect resolution of references to columns in the middle query block. (Bug #17398972)
• If accepting a connection attempt failed due to an out-of-memory error, the server could access a
stale thread structure for a previously disconnected connection, resulting in Valgrind errors. (Bug
#17398792)
• The SHA256 password authentication algorithm allocated a buffer one byte too short. (Bug
#17397073)
• For CASE expressions involving floating-point numbers, the max_length and decimal values could
be computed incorrectly. The logic for CASE was corrected to be the same as for COALESCE(),
which performs a similar operation. (Bug #17388045)
• A client crash occurred if mysql_set_server_option() or several other C API functions were
called before mysql_real_connect(). (Bug #17338958)
• In some cases, the optimizer wrote fixed-length temporary MyISAM tables to disk rather than
variable-length temporary tables. (Bug #17231940)
• Enabling the validate_password plugin could result in incorrect password hashes being stored in
the mysql.user table. (Bug #17065383)
• For debug builds, the second execution of a prepared statement processed using a semi-join could
cause a server exit. (Bug #16988465)
• A spurious assertion was raised for queries processed using a semi-join LooseScan optimization that
required rows to be returned in order. (Bug #16977389)
235
MySQL 5.7 Release Notes
• A circular dependency problem involving sql/sql_builtin.cc was resolved. (Bug #16877045)
• For accounts authenticated using the sha256_password plugin, setting the password after the
password had been expired did not clear the password-expired flag. (Bug #16872181)
• During server shutdown, file information was freed before calling query_logger.cleanup(),
leading to a memory leak. (Bug #16859266)
• For prepared INSERT INTO ... SELECT statements, nonexistent column names were not
reported during statement preparation, but only later at statement execution. (Bug #16820562)
• Multiple-table updates failed to update under certain conditions. (Bug #16767011)
• Crash recovery of temporary tables used uninitialized memory. (Bug #16754540)
• On OS X 10.7, a race condition involving vio_shutdown() and the select-based implementation of
vio_io_wait() could cause a server exit. (Bug #16354789, Bug #17733393)
• Host names in example URLs used within the source code were replaced by names in the
example.com domain, the domain intended by IANA for this purpose. (Bug #15890092)
• For utf8 and utf8mb4 strings, handler functions unnecessarily called a Unicode conversion
function. (Bug #14057034)
• On OS X, preloading of client plugins specified with the LIBMYSQL_PLUGINS environment variable
could fail unless the plugins were located in the hardwired default plugin directory. The C API now
checks during plugin preloading for a LIBMYSQL_PLUGIN_DIR environment variable which can
be set to the path name of the directory in which to look for client plugins. (Bug #13994567, Bug
#18110355)
• Certain (... NULL ...) IN (...) expressions returned NULL when they should return 0, such
as SELECT (NULL, 1) IN ((0, 0), (0, 0)). (Bug #13944462)
• Several -W warning flags were turned off for compilation in maintainer mode if MySQL was
configured with -DWITH_INNODB_MEMCACHED=1. (Bug #13898319)
• The optimizer set up for dynamic range access in some cases where range access cannot be used,
resulting in fallback to a table scan. (Bug #13814468)
• Executing mysqladmin shutdown for a server running with the thread pool plugin enabled and
servicing a large number of concurrent connections caused the server to exit abnormally. (Bug
#13788920)
• Calling the ExtractValue() function with an invalid XPath expression could in some cases lead to
a failure of the server. (Bug #12428404, Bug #61065)
• Use of a nonmultibyte algorithm for skipping leading spaces in multibyte strings could cause a server
exit. (Bug #12368495, Bug #18315770)
• With ONLY_FULL_GROUP_BY SQL mode enabled, a query that uses GROUP BY on a column derived
from a subquery in the FROM clause failed with a column isn't in GROUP BY error, if the query
was in a view. (Bug #11923239)
• The stage/sql/Waiting to get readlock Performance Schema instrument is no longer used
and has been removed. (Bug #71298, Bug #18035404)
• mysqlbinlog leaked memory in relation to --rewrite-db processing. (Bug #71283, Bug
#18027692)
• Previously, for EXPLAIN output, the rows-examined estimate for Performance Schema tables always
displayed as 1000. Now a more accurate estimate is displayed based on sizing parameters used
when allocating memory for each table. This results in no change of behavior because Performance
Schema tables have no indexes. (Bug #71278, Bug #18024455)
236
MySQL 5.7 Release Notes
• Optimizer trace output from the range optimizer could include raw binary data and generate
unprintable characters. Now binary data is printed in hex format. (Bug #71273, Bug #18023222)
• During configuration, CMake improperly checked for the C++ header file cxxabi.h. (Bug #71268,
Bug #18147458)
• Aggregating the results of a subquery in the FROM clause could produce incorrect results. (Bug
#71244, Bug #18014565)
• Previously, the first stage executed within a statement was stage/sql/init. This collided with a
different stage named init and was incompatible with the starting stage for SHOW PROFILE.
The first stage executed within a statement is now named stage/sql/starting. (Bug #71201,
Bug #17993294)
• CMake produced a warning in ssl.cmake due to malformed syntax. (Bug #71094, Bug #17905144)
• CMake produced not-useful warnings about INTERFACE_LINK_LIBRARIES policy. (Bug #71089,
Bug #17905155, Bug #17894997)
• mysqldump --single-transaction acquired metadata locks for each dumped table but did not
release them until the dump operation finished. Consequently, other DDL operations on a dumped
table blocked even after the table itself had been dumped. mysqldump now attempts to release
metadata locks earlier. (Bug #71017, Bug #17862905)
• sql_resolver.cc referred to partitioning code that should have been protected by an #ifdef,
even when MySQL was configured with -DWITH_PARTITION_STORAGE_ENGINE=OFF. (Bug
#71010, Bug #17876794)
• The wait/synch/mutex/sql/MYSQL_RELAY_LOG::LOCK_sync mutex was not properly
instrumented for the Performance Schema. (Bug #70939, Bug #17813333)
• The -DWITH_EXAMPLE_STORAGE_ENGINE=1 CMake option was ignored but should not have been.
If -DWITH_EXAMPLE_STORAGE_ENGINE=0 is given, the EXAMPLE storage engine is built as a
plugin. (Bug #70859, Bug #17772560)
References: See also: Bug #18324650.
• FLUSH STATUS cleared a variable that could result a subsequent implicit commit of an XA
transaction causing a server exit. (Bug #70854, Bug #17911445)
• Overhead was reduced within critical sections of the my_fopen() and my_register_filename()
mysys functions. Thanks to Po-Chun Chang for the patch. (Bug #70848)
• Several issues identified by the Coverity static analysis tool were fixed. Thanks to Honza Horak for
the patch. (Bug #70830, Bug #17760511)
• A query that creates a temporary table to find distinct values and has a constant value in the
projected list could produce incorrect results. (Bug #70657, Bug #17634335)
• Configuring with -DWITH_DEBUG=1 did not have the same effect as configuring with DCMAKE_BUILD_TYPE=Debug. (Bug #70647, Bug #17632854)
• The prototype of the Performance Schema instrumentation API mysql_cond_timedwait()
call was fixed to be drop-in compatible with pthread_cond_timedwait(). This fix affects only
implementers of third-party plugins. (Bug #70628, Bug #17702677)
• Some BETWEEN expressions on unsigned values were evaluated using signed arithmetic. Thanks to
Xiaobin Lin for the patch. (Bug #70622, Bug #17606942)
• An incorrect result could be returned for a query with an IF() predicate in the WHERE clause
combined with OUTER JOIN in a subquery that is transformed to a semi-join. (A workaround is
to disable semi-join using SET optimizer_switch='semijoin=off';) (Bug #70608, Bug
#17600176)
237
MySQL 5.7 Release Notes
• The server wrote an excessive number of “Sort aborted” messages to the error log. (Bug #70173,
Bug #17372396)
• When run by root, mysqld --help --verbose exited with a nonzero error code after displaying
the help message. (Bug #70058, Bug #17324415)
• Complex updates of Performance Schema tables involving joins or subqueries failed to update every
row. (Bug #70025, Bug #17309657)
• For debug builds, JSON-format EXPLAIN statements for queries that involve semi-join
materialization could cause a server exit. (Bug #70014, Bug #17305943)
• A deadlock error occurring during subquery execution could cause an assertion to be raised. (Bug
#69969, Bug #17307201)
• For an existing user, GRANT with an empty password (IDENTIFIED BY [PASSWORD] '') did not
change the password. (Bug #69899, Bug #17256161)
• Downloading of the Google Mock library could fail during configuration. This is fixed by requiring
CMake 2.8.2 or higher. (Bug #69854, Bug #17231722)
• Some files in the file_instances Performance Schema table were not being removed because
the file-removal operation was not instrumented. (Bug #69782, Bug #17209750)
• For the path specified with the --basedir option, mysql_plugin attempted to unlink the path
rather than free the memory in which the path was stored. (Bug #69752, Bug #17168602)
• A temporal literal string without delimiters and more than 14 digits was validated as a TIMESTAMP/
DATETIME value with a two-digit precision fractional seconds part. But fractional seconds should
always be separated from other parts of a time by a decimal point. (Bug #69714, Bug #17080703)
• For system variables that take a string value, SET statements permitted an unquoted value, but
values that contained dots were parsed incorrectly and only part of the value was assigned. For
example, SET GLOBAL slow_query_log_file = my_slow.log assigned the value my_slow.
Now such values must be quoted or an error occurs. (Bug #69703, Bug #17075846)
• It was not possible to query a view with an ORDER BY clause that referenced an alias in the SELECT
clause of the view definition, unless all columns in the view were named in the select list.
To handle this problem, the server now writes a view differently into the .frm file that stores the view
definition. If you experience view-evaluation errors such as just described, drop and recreate the
view so that the .frm file contains the updated view representation. (Bug #69678, Bug #17077305)
• The mysqladmin, mysqlbinlog, mysqlcheck, mysqldump, mysqlimport, mysqlslap, and
mysqlshow programs now support a --secure-auth option that prevents sending passwords to
the server in old (pre-4.1) format. This option is enabled by default; use --skip-secure-auth to
disable it. (Bug #69051, Bug #16723046)
• For the utf8_bin collation, ORDER BY LOWER(col_name) could produce incorrect ordering. (Bug
#69005, Bug #16691598)
• MySQL client programs from a Community Edition distribution could not connect using SSL to a
MySQL server from an Enterprise Edition. This was due to a difference in certificate handling by
yaSSL and OpenSSL (used for Community and Enterprise, respectively). OpenSSL expected a
blank certificate to be sent when not all of the --ssl-ca, --ssl-cert, and --ssl-key options
were specified, and yaSSL did not do so. To resolve this, yaSSL has been modified to send a blank
certificate when an option is missing. (Bug #68788, Bug #16715064)
• A full-text search combined with derived tables (subqueries in the FROM clause) caused a server exit.
Now if a full-text operation depends on a derived table, the server produces an error indicating that a
full-text search cannot be done on a materialized table. (Bug #68751, Bug #16539903)
238
MySQL 5.7 Release Notes
• COUNT(DISTINCT) sometimes produced an incorrect result when the last read row contained a
NULL value. (Bug #68749, Bug #16539979, Bug #71028, Bug #17867117)
• Some scripts displayed out-of-date information regarding where to report bugs. (Bug #68742, Bug
#16530527)
• Updating a FEDERATED table with UPDATE... JOIN caused a server exit when the local table
contained a single row and that row could be joined to a row in the FEDERATED table. (Bug #68354,
Bug #16324629)
• Messages written by the server to the error log for LDML collation definition problems were missing
the collation name. (Bug #68144, Bug #16204175)
• mysqlcheck did not correctly handle table names containing dots. (Bug #68015, Bug #16064833)
• Compilation problems were fixed for errors reported by Clang and gcc when compiling in C++11
mode. (Bug #66803, Bug #14631159)
• cmake/configure.pl listed instances of WITH_COMMENT rather than the correct option
COMPILATION_COMMENT. (Bug #65834, Bug #14298560)
• The make_atomic_cas_body64 implementation on IA32 with gcc but without gcc builtins could
be miscompiled due to an incorrect constraint. The patch also causes MySQL to use builtin atomics
when compiled using Clang. (Bug #63451, Bug #17242996)
• On OS X, the libmysqlclient dylib file linked to itself. (Bug #61699, Bug #13890998, Bug
#61243, Bug #12590037)
• The optimizer could choose ref access over eq_ref access when cost of a nonunique access was
evaluated before cost of a unique index. (Bug #54808, Bug #11762236)
• On Windows, mysql_install_db.pl could be run only from within the bin directory under the
installation directory. (Bug #42421, Bug #11751526)
• gcov printed warnings without file names. (Bug #33269, Bug #11747622)
• mysql_install_db referred to the obsolete mysqlbug script for reporting problems. It now refers
to http://bugs.mysql.com/ instead. (Bug #29716, Bug #11746921)
• The deprecated msql2mysql, mysql_convert_table_format, mysql_find_rows,
mysql_fix_extensions, mysql_setpermission, and mysqlaccess utilities were removed.
(Bug #27482, Bug #69012, Bug #69014, Bug #69015, Bug #69016, Bug #69017, Bug #11746603,
Bug #16699248, Bug #16699279, Bug #16699284, Bug #16699317, Bug #18179576)
Changes in MySQL 5.7.3 (2013-12-03, Milestone 13)
Note
This is a milestone release, for use at your own risk. Upgrades between
milestone releases (or from a milestone release to a GA release) are not
supported. Significant development changes take place in milestone releases
and you may encounter compatibility issues, such as data format changes that
require attention in addition to the usual procedure of running mysql_upgrade.
For example, you may find it necessary to dump your data with mysqldump
before the upgrade and reload it afterward.
• Audit Log Notes
• Compilation Notes
• Full-Text Search Notes
• Optimizer Notes
239
MySQL 5.7 Release Notes
• Packaging Notes
• Performance Schema Notes
• Security Notes
• Functionality Added or Changed
• Bugs Fixed
Audit Log Notes
• MySQL 5.7 changed audit log file output to a new format that has better compatibility with
Oracle Audit Vault. It is now possible to select either the old or new format using the new
audit_log_format system variable, which has permitted values of OLD and NEW (default NEW).
For details about each format, see The Audit Log File.
If you change the value of audit_log_format, use this procedure to avoid writing log entries in
one format to an existing log file that contains entries in a different format:
1. Stop the server.
2. Rename the current audit log file manually.
3. Restart the server with the new value of audit_log_format. The audit log plugin will create a
new log file, which will contain log entries in the selected format.
Compilation Notes
• CMake configuration for the Clang compiler sets more appropriate flags for building on Linux.
Specifically, -g -fno-omit-frame-pointer -fno-strict-aliasing is now added. (Bug
#17633291)
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Full-Text Search Notes
• Important Change; InnoDB: InnoDB now supports external full-text parser plugins. In order
to support InnoDB full-text parser plugins that are called in boolean mode, a new “position”
member has been added to the MYSQL_FTPARSER__BOOLEAN_INFO structure. If you plan to use
an existing full-text parser plugin that is called in boolean mode with MySQL 5.7.3 or later, you must
add support for the new “position” member, which is described in Writing Full-Text Parser Plugins.
Altering a MyISAM table with a full-text parser plugin to use InnoDB is also supported. For additional
information about full-text parser plugins, see Full-Text Parser Plugins.
Optimizer Notes
• The server no longer uses a temporary table for UNION statements that meet certain qualifications.
Instead, it retains from temporary table creation only the data structures necessary to perform result
column typecasting. The table is not fully instantiated and no rows are written to or read from it; rows
are sent directly to the client. The result is reduced memory and disk requirements, and smaller
delay before the first row is sent to the client because the server need not wait until the last query
block is executed. EXPLAIN and optimizer trace output will change: The UNION RESULT query block
will not be present because that block is the part that reads from the temporary table.
The conditions that qualify a UNION for evaluation without a temporary table are:
• The union is UNION ALL, not UNION or UNION DISTINCT.
• There is no global ORDER BY clause.
240
MySQL 5.7 Release Notes
• The union is not the top-level query block of an {INSERT | REPLACE} ... SELECT ...
statement.
(Bug #50674, Bug #11758470)
• The optimizer now is able to apply the range scan access method to queries of this form:
SELECT ... FROM t1 WHERE ( col_1, col_2 ) IN (( 'a', 'b' ), ( 'c', 'd' ));
Previously, for range scans to be used it was necessary for the query to be written as:
SELECT ... FROM t1 WHERE ( col_1 = 'a' AND col_2 = 'b' )
OR ( col_1 = 'c' AND col_2 = 'd' );
For the optimizer to use a range scan, queries must satisfy these conditions:
• Only IN() predicates are used, not NOT IN().
• On the left side of the IN() predicate, the row constructor contains only column references.
• On the right side of the IN() predicate, row constructors contain only runtime constants, which are
either literals or local column references that are bound to constants during execution.
• On the right side of the IN() predicate, there is more than one row constructor.
EXPLAIN output for applicable queries changes from full table scan or index scan to range
scan. Changes are also visible by checking the values of the Handler_read_first,
Handler_read_key, and Handler_read_next status variables. (Bug #31188, Bug #11747186)
• The modified filesort algorithm now includes an additional optimization designed to enable more
tuples to fit into the sort buffer: For additional columns of type CHAR or VARCHAR, or any nullable
fixed-size data type, the values are packed. For example, without packing, a VARCHAR(255) column
value containing only 3 characters takes 255 characters in the sort buffer. With packing, the value
requires only 3 characters plus a two-byte length indicator.
For data containing packable strings shorter than the maximum column length or many NULL
values, more records fit into the sort buffer. This improves in-memory sorting of the sort buffer and
performance of disk-based merge sorting of the temporary file.
In edge cases, packing may be disadvantageous: If packable strings are the maximum column
length or there are few NULL values, the space required for the length indicators reduces the number
of records that fit into the sort buffer and sorting is slower in memory and on disk.
Packing is not applicable if the filesort uses a priority queue for sorting, as is the case when an
ORDER BY ... LIMIT optimization is applied (see LIMIT Query Optimization).
If a filesort is done, optimizer trace output includes a filesort_summary block. For example:
"filesort_summary": {
"rows": 100,
"examined_rows": 100,
"number_of_tmp_files": 0,
"sort_buffer_size": 25192,
"sort_mode": "<sort_key, packed_additional_fields>"
}
The sort_mode value provides information about the algorithm used and the contents of the sort
buffer:
241
MySQL 5.7 Release Notes
<sort_key, rowid>: sort using row pointers
<sort_key, additional_fields>: sort using additional fields
<sort_key, packed_additional_fields>: sort using packed additional fields
For additional information about the filesort algorithm, see ORDER BY Optimization. For
information about the optimizer trace, see MySQL Internals: Tracing the Optimizer.
Packaging Notes
• Previously, MySQL Server distributions included the MySQL Reference Manual in Info format (the
Docs/mysql.info file). Because the license for the manual restricts redistribution, its inclusion in
Community packages caused problems for downstream redistributors, such as those who create
Linux distributions. Community distributions of MySQL Server no longer include the mysql.info file,
to make the repackaging and redistribution process easier (for example, the source tarball and its
checksum can be used directly). This change applies to all source and binary Community packaging
formats. Commercial (Enterprise) distributions are unchanged.
For those who wish to continue using the MySQL Reference Manual in Info format, we have made it
available at http://dev.mysql.com/doc/.
Performance Schema Notes
• The Performance Schema now instruments transactions. The information collected includes
quantitative and qualitative data including transaction duration, transaction counts, and frequency of
various transaction attributes such as isolation level and access modes. This information is collected
in tables that contain current and recent transaction events, and is aggregated in summary tables
across several dimensions, including user, account, and thread (client connection).
These new tables store transaction events:
• events_transactions_current: Current transaction events
• events_transactions_history: The most recent transaction events for each thread
• events_transactions_history_long: The most recent transaction events overall
There are also summary tables that provide aggregated transaction information.
Within the event hierarchy, wait events nest within stage events, which nest within statement events,
which nest within transactions. To reflect this, the NESTING_EVENT_TYPE column, in those tables
that have it, permits a new value, TRANSACTION, in addition to the existing values STATEMENT,
STAGE, and WAIT.
To permit control over configuration of transaction event collection, these changes were made to
Performance Schema setup tables:
• The setup_instruments table contains a new instrument named transaction. This
instrument is disabled by default.
• The setup_consumers table contains new consumer values with names corresponding to
the current and recent transaction event table names. These consumers may be used to filter
collection of transaction events. Only events_transactions_current is enabled by default.
• The setup_timers table contains a new row with a NAME value of transaction that indicates
the unit for transaction event timing. The default unit is NANOSECOND.
For more information, see Performance Schema Transaction Tables, and Transaction Summary
Tables.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
242
MySQL 5.7 Release Notes
• The Performance Schema now exposes metadata lock information:
• Locks that have been granted (shows which sessions own which current metadata locks)
• Locks that have been requested but not yet granted (shows which sessions are waiting for which
metadata locks).
• Lock requests that have been killed by the deadlock detector or timed out and are waiting for the
requesting session's lock request to be discarded
This information enables you to understand metadata lock dependencies between sessions. You can
see not only which lock a session is waiting for, but which session currently holds that lock.
The Performance Schema now also exposes table lock information that shows which table handles
the server has open, how they are locked, and by which sessions.
These specific changes were implemented:
• The metadata_locks and table_handles tables list current locks and lock requests for
metadata locks and table locks.
• The setup_instruments table now has a wait/lock/metadata/sql/mdl instrument for
metadata locks. This instrument is disabled by default.
• The performance_schema_max_metadata_locks system variable configures the maximum
number of metadata locks tracked in the metadata_locks table. For table_handles, the size
is configured by the existing performance_schema_max_table_handles system variable.
• The Performance_schema_metadata_lock_lost status variable indicates
the number of times a metadata lock could not be recorded. For table_handles,
tables that are opened but cannot be instrumented are counted by the existing
Performance_schema_table_handles_lost status variable.
For more information, see Performance Schema Lock Tables.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
Security Notes
• Incompatible Change: Previously, the --ssl option has been treated as advisory: When given,
an encrypted connection was permitted but not required. Also, several other --ssl-xxx options
implied --ssl. Because of this, the option was usually not used explicitly as --ssl, but in its
negated form as --ssl=0, which prevents use of encryption. This was true on both the client and
server sides, and true for any synonyms of --ssl (--ssl=1, --enable-ssl) or --ssl=0 (-skip-ssl, --disable-ssl).
Now the meaning of --ssl has changed on the client-side only. (There are no secure-connection
changes on the server side.)
When given on the client side as --ssl (or a synonym), the option is no longer advisory but
prescriptive. Given a server enabled to support encrypted connections, a client program can require
an encrypted connection by specifying only the --ssl option. (Previously, it was necessary for the
client to specify either the --ssl-ca option, or all three of the --ssl-ca, --ssl-key, and --sslcert options.) The connection attempt fails if an encrypted connection cannot be established. This
is an incompatible change in the sense that MySQL client commands that use --ssl now will fail
unless an encrypted connection can be established. On the other hand, for a successful connection
attempt, the connection is guaranteed to be secure. Previously, there was no such guarantee.
243
MySQL 5.7 Release Notes
In addition, other --ssl-xxx options on the client side no longer imply --ssl and are advisory
in the absence of --ssl: The client attempts to connect using encryption but falls back to an
unencrypted connection if an encrypted connection cannot be established.
There is no change in the meaning of --ssl=0 (and its synonyms) to prevent use of encryption and
override other --ssl-xxx options.
A new MYSQL_OPT_SSL_ENFORCE option is available for the mysql_options() C API function
to indicate whether to require the connection to use encryption. If enabled, it has the same effect
as specifying --ssl on the command line: If an encrypted connection cannot be established, the
connection attempt fails.
For more information, see Command Options for Encrypted Connections, and mysql_options().
The MASTER_SSL=1 option for the CHANGE MASTER TO statement has changed as well, analogous
to the change in the meaning of --ssl. That is, when given, the slave connection to the master must
use encryption or the connection attempt fails. (Bug #11744828)
Functionality Added or Changed
• Incompatible Change: Several statement instruments in the setup_instruments table are used
by the Performance Schema during the early stages of statement classification before the exact
statement type is known. These instruments were renamed to more clearly reflect their “abstract”
nature:
Old Instrument Name
New Instrument Name
statement/com/
statement/abstract/new_packet
statement/com/Query
statement/abstract/Query
statement/rpl/relay_log
statement/abstract/relay_log
In addition, statistics for abstract instruments are no longer collected in the following tables, because
no such instrument is ever used as the final classification for a statement:
events_statements_summary_by_thread_by_event_name
events_statements_summary_by_account_by_event_name
events_statements_summary_by_user_by_event_name
events_statements_summary_by_host_by_event_name
events_statements_summary_global_by_event_name
Applications that refer to the old instrument names must be updated with the new names. For more
information about the use of abstract instruments in statement classification, see Performance
Schema Statement Event Tables. (Bug #16750433, Bug #17271055)
• Incompatible Change: The EXPLAIN statement has been changed so that the effects of the
EXTENDED and PARTITIONS keywords are always enabled. EXTENDED and PARTITIONS are still
recognized, but are superfluous and have been deprecated. They will be removed from EXPLAIN
syntax in a future MySQL release.
EXPLAIN output differs as follows as a result of this change:
• The filtered and partitions columns appear in EXPLAIN output regardless of whether the
EXTENDED and PARTITIONS keywords are specified. This is an incompatible change for
applications that expect to identify column information by position rather than by name, and such
applications will need adjustment.
• SHOW WARNINGS immediately following EXPLAIN shows additional execution plan information
regardless of whether the EXTENDED keyword is specified. (An additional deprecation warning is
included if the statement includes the EXTENDED or PARTITIONS keyword.)
244
MySQL 5.7 Release Notes
• Performance; InnoDB: The log_write_up_to function, which writes to redo log files up to
a certain log sequence number (LSN) and optionally flushes writes to disk, has been refactored
to improve performance for workloads with heavy log_sys::mutex contention and where
innodb_flush_log_at_trx_commit=2.
• Performance: The LOCK_thread_count mutex protected several independent internal server
structures and variables, and was a bottleneck, particularly affecting server performance in the
circumstance when many clients were connecting and disconnecting at once. This mutex was
decomposed into more specific mutexes and atomic operations to alleviate the bottleneck and
improve performance.
As part of this work, the following status variables are no longer visible in the embedded
server because for that server they were not updated and were not meaningful:
Aborted_connects, Connection_errors_accept, Connection_errors_internal,
Connection_errors_max_connections, Connection_errors_peer_addr,
Connection_errors_select, Connection_errors_tcpwrap.
• InnoDB: The InnoDB memcached plugin now supports inserts and reads on mapped InnoDB tables
that have an INTEGER defined as the primary key. (Bug #17315083, Bug #17203937)
• Replication: Replication filtering rules can now be set dynamically on the slave using the SQL
statement CHANGE REPLICATION FILTER introduced in this release. This statement has the
same effect as starting the slave mysqld with one or more of the options --replicate-dodb, --replicate-ignore-db, --replicate-do-table, --replicate-ignore-table,
--replicate-wild-do-table, --replicate-wild-ignore-table, and --replicaterewrite-db.
For example, issuing the statement CHANGE REPLICATION FILTER REPLICATE_DO_TABLE =
(d1.t2) is equivalent to starting the slave mysqld with --replicate-do-table='d1.t2'.
CHANGE REPLICATION FILTER differs from the server options in that, to take effect, the statement
requires only that the slave SQL thread be stopped beforehand and restarted afterwards, using STOP
SLAVE SQL_THREAD and START SLAVE SQL_THREAD, respectively.
This statement leaves any existing replication filtering rules unchanged; to unset all filters of a given
type, set the filter to an empty list, as shown in this example:
CHANGE REPLICATION FILTER REPLICATE_DO_DB = ();
You can list multiple replication filtering rules in the same statement, separated by commas. When
multiple instances of the same rule are found, only the last instance is used.
For more information, see CHANGE REPLICATION FILTER Syntax; see also How Servers Evaluate
Replication Filtering Rules. (Bug #15877941, Bug #11752237, Bug #67362, Bug #43366)
• Replication: Previously, with semisynchronous replication enabled, the master waited for
a single slave acknowledgment per transaction before proceeding. A new system variable,
rpl_semi_sync_master_wait_for_slave_count, enables the number of slave
acknowledgments required per transaction to be configured. The minimum (and default) value is 1.
The maximum is 65,536. Performance is best for small values of this variable.
• Microsoft Windows: The implementation of condition variables specific to Windows XP and
Windows Server 2003 was removed from the source code because MySQL is not supported on
those platforms as of MySQL 5.6. (Bug #17332056)
• The Performance Schema now instruments the read/write lock Delegate::lock, which is used for
the following classes:
Trans_delegate
Binlog_storage_delegate
245
MySQL 5.7 Release Notes
Binlog_transmit_delegate
Binlog_relay_IO_delegate
A different instrument name is used for each subclass, to have distinct statistics for distinct uses. The
instruments are visible in the schema.setup_instruments table and have these names:
wait/synch/rwlock/sql/Trans_delegate::lock
wait/synch/rwlock/sql/Binlog_storage_delegate::lock
wait/synch/rwlock/sql/Binlog_transmit_delegate::lock
wait/synch/rwlock/sql/Binlog_relay_IO_delegate::lock
(Bug #17590161, Bug #70577)
• Some dependencies between client-side plugin header files were removed:
• The MYSQL_PLUGIN_EXPORT macro required by plugin declarations is now declared directly in
mysql/client_plugin.h instead of getting the definition from mysql/plugin.h. That macro
was the only thing required by client-side plugins and declared in server-side header mysql/
plugin.h, so including mysql/client_plugin.h in an application no longer requires the
application to also include mysql/plugin.h.
• mysql/plugin_trace.h no longer uses C_MODE_START or C_MODE_END. Consequently,
including mysql/plugin_trace.h in an application no longer requires the application to also
include my_global.h.
Applications might require mysql/plugin.h or my_global.h for other reasons, of course. (Bug
#17582168)
• Overhead for Performance Schema instrumentation associated with thread creation was reduced.
(Bug #17539520)
• It is now possible to enable the Performance Schema but exclude certain parts of the
instrumentation. For example, to enable the Performance Schema but exclude stage and statement
instrumentation, do this:
shell> cmake . -DWITH_PERFSCHEMA_STORAGE_ENGINE=1 \
-DDISABLE_PSI_STAGE=1 \
-DDISABLE_PSI_STATEMENT=1
For more information, see the descriptions of the DISABLE_PSI_XXX CMake options in MySQL
Source-Configuration Options. (Bug #17478068)
• A new CMake option, WITH_ASAN, permits enabling AddressSanitizer for compilers that support it.
(Bug #17435338)
• Several compilation warnings were fixed that occurred when compiling without debugging enabled.
(Bug #17332094)
• A new ER_ENGINE_OUT_OF_MEMORY error code is available for use by storage engines to report
out-of-memory conditions. (Bug #16807964)
• Overhead for deprecation warnings was reduced. (Bug #70402, Bug #17497869)
• For GRANT statements, ER_SP_DOES_NOT_EXIST errors for nonexistent stored procedures and
functions now specify PROCEDURE does not exist or FUNCTION does not exist rather than
the less-specific PROCEDURE or FUNCTION does not exist. (Bug #69628, Bug #17036976)
• The hash function used for metadata locking was modified to reduce overhead. (Bug #68487, Bug
#16396598)
• Because there are new API functions (mysql_get_option(), mysql_reset_connection()),
the library ABI version is now 18.2. Shared library names now include 18.2 where appropriate.
246
MySQL 5.7 Release Notes
• A new mysql_get_option() C API function is available that returns the current value of applicable
mysql_options() options. See mysql_get_option().
• When a connection is returned to the thread pool plugin, the connection thread context
must be cleaned up. Previously, this was done using COM_CHANGE_USER (which is like the
mysql_change_user() C API function). However, that operation reauthenticates, which is
unnecessary network roundtrip overhead in this context.
Now it is possible for client connection state to be reset in a more lightweight manner without causing
reauthentication. The API is exposed publicly through these changes:
• A new COM_RESET_CONNECTION protocol command (defined in mysql_com.h)
• A new mysql_reset_connection() C API function
• A new resetconnection command for the mysql client
Resetting a connection has effects similar to mysql_change_user() or an auto-reconnect
except that the connection is not closed and reopened, and reauthentication is not done. See
mysql_change_user()) and see C API Automatic Reconnection Control).
For more information, see mysql_reset_connection() and mysql — The MySQL Command-Line
Tool.
Bugs Fixed
• Incompatible Change: For logging to the general_log and slow_log tables in the mysql
database, log lines containing multiple character sets were not always handled correctly. The
general_log.argument and slow_log.sql_text columns now have been changed from
MEDIUMTEXT to MEDIUMBLOB. Consequently, no character set transformation is done for logging to
tables now, which aligns it with logging to files.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the mysql system database. (Bug #14575847)
• Important Change; Replication: START SLAVE UNTIL SQL_AFTER_GTIDS did not cause the
slave to stop until the next GTID event was received following execution of the transaction having the
indicated GTID, which could cause issues in the case when the next GTID event is delayed, or does
not exist. Now the slave stops after completing the transaction with that GTID. (Bug #14767986)
• Important Change; Replication: It was possible to start the server with binary logging enabled but
no server ID specified; in such cases, the server would set server_id to 1 (rather than 0) while
slaves remained unable to connect.
Now --server-id must be used when starting the server with binary logging enabled, otherwise
the server is unable to start. If --server-id=0 is used, this value is no longer changed by the
server; in this case, updates are written to the binary log, but slaves are unable to connect. Using
--server-id without specifying a value has the same effect as setting it explicitly to 0. (Bug
#11763963, Bug #56739)
• InnoDB; Replication: The InnoDB mecached plugin would update a record before inserting to the
binary log, which would cause slave server replication to stop. The insert should occur before the
update. (Bug #17358875)
• InnoDB: When new indexes are added by an ALTER TABLE operation, instead of only saving
table-level statistics and statistics for the new indexes, InnoDB would save statistics for the entire
table, including the table's other indexes. This behavior slowed ALTER TABLE performance. (Bug
#17848838, Bug #16511145)
• InnoDB: A regression introduced by the fix for Bug#17371537 resulted a memory leak for
memcached insert operations. (Bug #17738935)
247
MySQL 5.7 Release Notes
References: See also: Bug #17371537.
• InnoDB: Fault-tolerant code found in the log apply code for InnoDB ALTER TABLE ... IN
PLACE could result in data corruption. (Bug #17625063, Bug #17512497)
• InnoDB: The trx->error_key_num field was not initialized in the error injection code found
in storage/innobase/handler/handler0alter.cc. The error_key_num field is usually
0 but can be a non zero value if the memory buffer of a DDL transaction object is reused. (Bug
#17624926)
• InnoDB: Databases names beginning with a digit would cause a full-text search (FTS) parser error.
(Bug #17607956)
References: See also: Bug #17161372.
• InnoDB: An ALTER TABLE ... CHANGE [COLUMN] operation would result in an
rbt_empty(index_cache->words) assertion. (Bug #17536995)
• InnoDB: buf_flush_event would be created at flush thread startup instead of server startup.
Also, buf_flush_event would be signaled when InnoDB is started in read-only mode. (Bug
#17516062)
• InnoDB: CHECK TABLE would ignore the QUICK option. (Bug #17513737)
• InnoDB: An excessive amount of memory would be consumed when querying
INFORMATION_SCHEMA.INNODB_FT_INDEX_TABLE. The problem would occur for very large fulltext search indexes. (Bug #17483582, Bug #70329)
• InnoDB: Running SHOW ENGINE INNODB STATUS on one connection thread and killing that thread
by running a KILL CONNECTION statement from a different connection thread would result in a
severe error. (Bug #17474166)
• InnoDB: In debug builds, test case failures would occur due to ibuf_contract_ext performing
merges and dict_stats_update returning evicted pages back into the buffer pool while
ibuf_change_buffering_debug is enabled. (Bug #17446090)
• InnoDB: InnoDB failed to return an error when attempting to run a query after discarding the
tablespace. (Bug #17431533)
• InnoDB: A severe error would occur after discarding a tablespace. (Bug #17430207)
• InnoDB: Data in the OPERATION column of performance_schema.events_waits_current
table was incorrect due to a code regression introduced in MySQL 5.7.2. (Bug #17429480)
• InnoDB: During a TRUNCATE TABLE operation, InnoDB: Trying to TRUNCATE a missing
index of table ... warnings would be printed to the error log. These warnings should not be
printed when the index is a full-text search (FTS) index. (Bug #17402002, Bug #70226)
References: See also: Bug #12429565.
• InnoDB: During parallel full-text search (FTS) index creation, a scanner thread reads in documents
and passes them to the tokenizer. The tokenizer frees documents from memory when tokenization
is complete. When tokenizing documents with a large amount of text, the tokenizer thread would
not keep pace with the scanner thread. As a result, memory would not be freed fast enough and the
“tokenization pending list” would grow in size. (Bug #17384979)
• InnoDB: row_scan_index_for_mysql would allocate a buffer size of UNIV_PAGE_SIZE for
row_search_for_mysql. When the record length was greater than UNIV_PAGE_SIZE, a Valgrind
error would occur. (Bug #17378106)
• InnoDB: trx_create and trx_free would be called for every memcached get request. (Bug
#17371537, Bug #70172)
248
MySQL 5.7 Release Notes
• InnoDB: A full-text search (FTS) BOOLEAN MODE query with an invalid character in the query string
could result in a memory access violation failure. (Bug #17350055)
• InnoDB: An assertion would be raised when the database initialization thread encountered other
threads performing buffer pool flushing. (Bug #17349975)
• InnoDB: Full-text index creation on a large table failed due to insufficient temporary table space and
result in a misleading “incorrect key file” error. (Bug #17339606)
• InnoDB: The UNIV_BLOB_DEBUG compile-time debug flag, which is not often used and is limited by
its inability to work across crash recovery, has been removed in order to simplify code refactoring.
(Bug #17338452)
• InnoDB: The UNIV_SEARCH_DEBUG compile-time debug check, which has never reported a failure,
has been removed along with all references to it. (Bug #17338432)
• InnoDB: trx_sys_t::ro_trx_list has been removed. Adding and removing transactions
from the ro_trx_list can be costly, and placing transactions on the list by default is no longer
necessary after mutex related optimizations implemented in MySQL 5.7.2. User transactions are still
placed on the trx_t::mysql_trx_list. Currently, background read-only transactions are not
placed on any list. (Bug #17332300)
• InnoDB: When innodb_file_per_table is set to OFF, replication failed with error code 1880
when truncating tables. For tables that reside in the shared tablespace, the truncate log file name
used during the truncate action was not unique. The error is due to a MySQL 5.7.2 code regression
related to Bug #14174004. (Bug #17327409)
• InnoDB: When InnoDB is retrieving rows and a KILL QUERY statement is issued, InnoDB would
return false errors. (Bug #16950658)
• InnoDB: In btr_validate_level there are checks to ensure that all B-tree pages are marked
when allocated. The checks failed on the change buffer because the allocation of change buffer
pages is handled differently than other B-tree pages. (Bug #16884217)
• InnoDB: The hardcoded size for the srv_max_n_threads variable was insufficient. The variable
setting is now configured based on the maximum number of connection threads and InnoDB
background threads. (Bug #16884077)
• InnoDB: InnoDB would set UNIV_WORD_SIZE to 4 for both Windows 32-bit and 64-bit systems.
With this patch, UNIV_WORD_SIZE is set to 8 on 64-bit Windows systems. This patch also removes
UNIV_WORD_ALIGNMENT, which is no longer used. (Bug #16774645)
• InnoDB: A SELECT COUNT(*) query would take a long time to complete when run concurrently
with a LOAD DATA operation. The mtr_memo_contains function, which determines if an object is
part of a memo in a mini transaction, contained a nested loop that caused the query to run slowly.
(Bug #16764240, Bug #69141)
• InnoDB: When the change buffer is enabled, InnoDB failed to write a transaction log record when
merging a record from the insert buffer to a secondary index page if the insert was performed as an
“update-in-place”. (Bug #16752251, Bug #69122)
• InnoDB: Due to a regression in MySQL 5.6, creating or dropping tables with
innodb_force_recovery set to 3 (SRV_FORCE_NO_TRX_UNDO) failed. Additionally, this bug fix
includes a code modification that sets InnoDB to read-only when innodb_force_recovery is set
to a value greater than 3 (SRV_FORCE_NO_TRX_UNDO). (Bug #16631778, Bug #69892)
• InnoDB: An InnoDB memcached configuration error message contained an incorrect file name.
The error message stated, Please create config table containers in database
innodb_memcache by running innodb_config.sql. error 31. The correct file name
is innodb_memcached_config.sql. Also, the “error 31” portion of the error message has been
translated to its text equivalent, which is “Table not found”. (Bug #16498810, Bug #68684)
249
MySQL 5.7 Release Notes
• InnoDB: In mutex_spin_wait(), the sync_array_reserve_cell function could fail to find
an empty slot on systems with sync wait arrays that are small in size, resulting in an error. (Bug
#16245498)
• InnoDB: When index_read_map is called for an exact search and fails to return a record due to
non-matching search criteria, the cursor would be positioned on the next record after the searched
key. A subsequent call to index_next would return the next record instead of returning the
previous non-matching row, thereby skipping a record. (Bug #14621190, Bug #15965874, Bug
#17314241, Bug #70038, Bug #17413093, Bug #12860669, Bug #60220, Bug #17565888)
• InnoDB: An implicit rollback caused the server to halt when restarting with an
innodb_force_recovery value of 3 or greater. This bug was addressed by the combination of
fixes for Bug #16310467 and Bug #17253499. (Bug #14178835)
References: See also: Bug #16310467, Bug #17253499.
• InnoDB: An infinite loop could occur in buf_page_get_gen when handling compressed-only
pages. (Bug #12560151, Bug #61132)
• InnoDB: InnoDB would attempt to free BLOB pages already marked as free. (Bug #11762662, Bug
#55284)
• InnoDB: Converting a table with a large number of columns from MyISAM to InnoDB would cause
an assertion due to insufficient log buffer space. Instead of asserting, InnoDB now attempts to
increase log buffer size automatically if the redo log size is too large. (Bug #11758196, Bug #50366)
• Partitioning: The storage engine was set incorrectly during a rebuild of a partition; the table storage
engine was ignored and the default storage engine used instead. Thus, in MySQL 5.1, it was
possible for REBUILD PARTITION to change the partition storage engine from InnoDB to MyISAM,
and for the reverse (rebuilding partitions of MyISAM tables causing the partitions to use InnoDB) to
occurin MySQL 5.5 and later. Now, when rebuilding partitions, the storage engine actually used by
the table is checked and used by the handler for the rebuild operation, so that the partition storage
engine is not inadvertently changed. (Bug #17559867)
• Partitioning: Index condition pushdown did not work with partitioned tables. (Bug #17306882, Bug
#70001)
• Partitioning: After disabling the parent table's indexes with ALTER TABLE ... DISABLE KEYS,
rebuilding any of its partitions enabled the indexes on those partitions, leading MyISAM to fail with an
error when the optimizer tried to use one of the affected indexes.
Now in such cases, we check for disabled indexes on the table before rebuilding any of its partitions.
If the indexes have been disabled, then we disable them on the partition following the rebuild. (Bug
#16051817)
• Replication: When GTID-based replication was used with an intra-schema multi-threaded slave,
transactions were assigned to the first worker thread only. (Bug #17590616, Bug #70536)
• Replication: The WORKER_ID column of the replication_execute_status_by_worker
table did not use the internal id column values from the mysql.slave_worker_info table, as
expected. (Bug #17514406, Bug #70426)
• Replication: The THREAD_ID column values shown in the
performance_schema.replication_execute_status_by_worker table used the same
thread IDs shown in the output from SHOW PROCESSLIST, rather than those used by other
performance_schema tables. (Bug #17440991, Bug #70423)
References: See also: Bug #17473308, Bug #17526982.
• Replication: The final argument in the SET clause of a LOAD DATA ... SET statement was
repeated in the binary log. (Bug #17429677, Bug #70277)
250
MySQL 5.7 Release Notes
• Replication: When an error encountered by the dump thread while reading events from the active
binary log file was a temporary error, so that the dump thread tried to read the event, it was possible
for the dump thread to seek the wrong position, which could cause one or more events to be resent.
To prevent this, the thread's position is obtained after each correct read of an event.
In addition, with this fix, only binary logs that are not closed normally are marked as possibly being
corrupted.
Finally, two warnings are added; these are now returned when a dump thread encounters a
temporary error. (Bug #17402313)
• Replication: Setting rpl_semi_sync_master_enabled while the master was waiting for a reply
from the slave could in some cases cause the master to fail. (Bug #17327454, Bug #70045)
• Replication: When stopping the I/O thread, it was possible with a very large transaction (equivalent
to a binary log size greater than 100MB) that the thread did not receive the transaction to the end.
When reconnecting with MASTER_AUTO_POSITION=1 it then tried to fetch changes from the next
transaction, which could lead to loss of the incomplete transaction and its data. (Bug #17280176,
Bug #69943)
• Replication: Trying to set CHANGE MASTER TO ... MASTER_AUTO_POSITION = 0 failed with
error 1777 (ER_AUTO_POSITION_REQUIRES_GTID_MODE_ON). (Bug #17277744)
• Replication: No error was written to the log file when writing an incident event to the binary log. This
meant that the user was not alerted that a slave server will later be stopped by the incident event. To
prevent this from happening, error messages are now written in the log file for all incidents written to
the binary log. (Bug #17258782)
• Replication: The value of LAST_INSERT_ID() was not correctly replicated when filtering rules
were used on the slave. (Bug #17234370, Bug #69861)
• Replication: RESET SLAVE ALL reset only the host, port, user, password, and log positions. Now it
resets all connection parameters. (Bug #17185647)
• Replication: An internal function used for storing GTID values could sometimes try to handle them
as strings of the wrong length. (Bug #17032712, Bug #69618)
• Replication: During row-based replication with binlog_row_image set to MINIMAL, updating only
some columns of a table having 9 or more columns caused mysqlbinlog to fail when it was used
with the --verbose option. (Bug #16960133)
• Replication: When a master with semisynchronous replication enabled was shut down, the master
failed to wait for either a semisyncnronous ACK or timeout before completing the shutdown. This
prevented semisynchronous replication from reverting to asynchronous replication and allowed open
transactions to complete on the master, which resulted in missing events on the slave.
To fix this problem, dump threads are now stopped last during shutdown, after the client is told to
stop, so that, if the dump thread has pending events from active clients, they can be sent to the
slave. (Bug #16775543)
• Replication: Issuing a GRANT statement with invalid parameters caused the master to write
LOST_EVENTS events into its binary logs, causing replication to stop. Now such cases, if one or
more grants or revocations of privileges are successful, an incident is written to the log; otherwise,
only a warning is logged. (Bug #16629195, Bug #68892)
• Replication: START SLAVE failed when the server was started with the options --master-inforepository=TABLE relay-log-info-repository=TABLE and with autocommit set to 0,
together with --skip-slave-start.
A workaround for previous versions of MySQL is to restart the slave mysqld without the --skipslave-start option. (Bug #16533802)
251
MySQL 5.7 Release Notes
• Replication: A number of unneeded initializations of objects that were used but not actually needed
for reading the relay log info log were removed. (Bug #16291602)
• Replication: mysqlbinlog now supports the same command-line options relating to SSL as
mysql, mysqladmin, and other MySQL client programs. See Command Options for Encrypted
Connections, for more information. (Bug #11751199, Bug #41975)
• Replication: Previous versions of mysqlbinlog did not correctly accept the ssl-ca option in an
option file. This fix ensures that this option can be correctly used. In earlier versions a work around is
to use the loose-ssl-ca option. (Bug #74864, Bug #20032654)
• For debug builds, an error occurring during DELETE IGNORE could raise an assertion. (Bug
#17720294)
• UNION ALL statements for which one SELECT returned zero rows could result in an incorrect
FOUND_ROWS() value. (Bug #17708480)
• Enabling Index Merge optimizer switches and setting a small sort_buffer_size value could lead
to a server exit. (Bug #17617945)
• Some license and documentation files were missing from Windows MSI packages. (Bug #17584523)
• UNION ALL queries for which the last SELECT selected an aggregate value from an empty table
resulted in an incorrect FOUND_ROWS() value. (Bug #17580869)
• Semi-join materialization strategy was not used for VARCHAR columns longer than 512 bytes,
resulting in use of a less-efficient strategy and worse query performance. (The limit in characters
rather than bytes depends on the column character set; 170 characters for utf8, for example.) (Bug
#17566396)
• Disconnect processing overhead was reduced for sessions that have no outstanding prepared
statements. Previously, a global mutex was acquired to handle these, but there is no need to do so in
the absence of such statements. (Bug #17560986)
• The optimizer did not consider a clustered primary key as a covering index unless all columns
required for a query were in the primary key definition. This incorrectly raised the calculated cost of
using the index and caused it not to be used in some cases when it would be more efficient than the
index otherwise chosen. (Bug #17560636)
• Selecting from the session_connect_attrs Performance Schema table under high load could
cause a server exit. (Bug #17542370)
• The Performance Schema had a race condition adding and deleting stored procedure entries that
could raise an assertion. (Bug #17529279)
• DROP TRIGGER succeeded even with the read_only system variable enabled. (Bug #17503460)
• An incorrect result could be produced by a simple COUNT(DISTINCT) query on a table that
contains a large number of distinct values. This was more likely when tmp_table_size or
max_heap_table_size were set to small values. (Bug #17500866)
• Performance Schema memory instrumentation overhead was reduced.
Memory allocated internally by the Performance Schema was not reported by the memory
instrumentation. This was corrected, and there is now a memory/performance_schema/
internal_buffers instrument (disabled by default) that can be enabled to obtain this information.
(Bug #17493868)
• Stored programs were not listed in the objects_summary_global_by_type Performance
Schema table. (Bug #17472833)
• my_print_stacktrace() printed a Reference Manual URL that pointed to the 5.1 manual. It now
is parameterized for the current server series. (Bug #17465503)
252
MySQL 5.7 Release Notes
• In debug builds, SHOW PROCEDURE CODE raised an assertion. (Bug #17434385)
• Compilation failures under Visual Studio 2012 were corrected. (Bug #17430236)
• For JSON-format EXPLAIN statements, materialized views were incorrectly labeled as
optimized_away_subqueries rather than as materialized_from_subquery. (Bug
#17428655)
• KILL with an invalid thread ID value could raise an assertion. (Bug #17420682)
• An assertion was raised if a statement tried to set an exception condition in a diagnostics area which
already contained an exception or completion condition. This could occur if a failed stored program
tried to transfer its exception condition to the diagnostics area of its caller that already contained a
condition. (Bug #17400687)
• In the Performance Schema memory instrumentation, statistics collected for memory-free operations
could be under-evaluated, leading to the appearance of a memory leak. (Bug #17400029)
• Compiling without the Performance Schema resulted in unresolved symbols. (Bug #17399658)
• Some warnings produced by mysql_install_db referred to the now-deprecated log_warnings
system variable. These have been updated to refer to log_error_verbosity instead. (Bug
#17363350)
• An assertion was raised if SET PASSWORD was used for an account that has been manually deleted
from the mysql.user table but still present in memory. (Bug #17359329)
• Savepoints could not be used successfully following an ER_LOCK_DEADLOCK error (or
ER_LOCK_WAIT_TIMEOUT error, if innodb_rollback_on_timeout was enabled). (Bug
#17356954)
References: This issue is a regression of: Bug #14188793.
• The CLIENT_CONNECT_WITH_DB flag was improperly handled in the C client library. This could lead
to a malformed packet sent to the server. (Bug #17351732)
• Upgrades using RPM packages failed if the MySQL server was running due to failure to ignore the
mysqld_safe.pid file created by mysqld_safe. (Bug #17343851)
• The mysql_real_connect() C API function could leak memory if it failed. (Bug #17337684)
• The filesort implementation sometimes failed to allocate enough buffer space, leading to a server
exit. (Bug #17326567)
• Cost comparison for ref access could be inaccurate. (Bug #17303649)
• The mysql_options() C API function could leak memory if called more than once with the
MYSQL_SET_CLIENT_IP option. (Bug #17297012)
• The CONV() function could call abs(INT_MIN), which is undefined, and cause a server exit. (Bug
#17296644)
• An error array in the SSL code was missing a comma, leading to implicit concatenation of adjacent
messages and a resulting off-by-one error in the relationship between error numbers and messages.
(Bug #17294150)
• Full-text search on InnoDB tables failed on searches that used the + boolean operator. (Bug
#17280122)
• For single-threaded workloads, the optimizer recognizes some special cases for which it can avoid
function calls and enhance performance. (Bug #17234723)
• The my_load_path() function could in some cases calculate a path value incorrectly. (Bug
#17204851)
253
MySQL 5.7 Release Notes
• Temporary table columns were marked as temporarily nullable without taking into account the
presence of triggers for the table. This could lead to NOT NULL columns being updated to NULL by a
multiple-table UPDATE statement. (Bug #17055378)
• In debug builds, an assert could be raised if a statement was killed while executing a trigger. (Bug
#17049537)
• Within a stored program, comparison of the value of a scalar subquery with an IN clause resulted in
an error for the first execution and raised an assertion for the second execution. (Bug #17029399)
• Information was not transferred between two optimizer modules because there were duplicate
variables for the same information. This could lead to suboptimal query execution plans and incorrect
query results. (Bug #16982071, Bug #70021, Bug #17310161)
• JSON-format EXPLAIN statements could leak memory. (Bug #16970785)
• Queries with ROLLUP and an inner subquery with a reference to an outer field could raise an
assertion. (Bug #16967281)
• GRANT without an IDENTIFIED BY clause resulted in an error even for existing users. (Bug
#16938568)
• GROUP_CONCAT() with an invalid separator could cause a server exit. (Bug #16870783)
• For partitioned tables, queries could return different results depending on whether Index Merge was
used. (Bug #16862316)
References: See also: Bug #17648468, Bug #176588348, Bug #18167648.
• mysqltest_embedded does not work with the --ps-protocol option, so it now issues a warning
if that option is given. (Bug #16817580)
• An internal InnoDB string routine could write past the end of a buffer. (Bug #16765410)
• GIS intersection-related code was missing a return value check, leading to a loop in nondebug builds
and a raised assertion in debug builds. (Bug #16659166)
• For debug builds, when the optimizer removed an Item_ref pointing to a subquery, it caused a
server exit. (Bug #16509874)
References: This issue is a regression of: Bug #16318585.
• It is no longer possible to expire the password for anonymous-user accounts because an anonymous
user cannot execute SET PASSWORD to reset the account password. (Bug #16483619)
• On Windows, a MySQL client program that simply used #include <mysql.h> could not be
compiled due to missing Windows declarations in that file. The same program would compile on
other platforms. (Bug #16409270)
References: See also: Bug #17514554.
• HANDLER READ could cause a server exit due to wrongly considering columns as constant. (Bug
#16386136)
• Using the binary client/server protocol, the second execution of a prepared statement for a query
with parameters in the LIMIT clause raised an assertion. (Bug #16346241)
• Very long database names in queries could cause the server to exit. (Bug #15912213, Bug
#16900358)
• Memory allocated for the Performance Schema was not freed at server shutdown. (Bug #14771682)
254
MySQL 5.7 Release Notes
• If an INSTALL PLUGIN statement contained invalid UTF-8 characters in the shared library name,
it caused the server to hang (or to raise an assertion in debug builds). (Bug #14653594, Bug
#23080148)
• Standalone Windows MSI packages did not have the ALLUSERS property set. They now set
ALLUSERS=1. For earlier MSI packages in this MySQL series, a workaround is to use the following
command:
C:\> msiexec /i msi_installer_name ALLUSERS=1
(Bug #14647206)
• Deadlocks involving metadata locks and InnoDB deadlocks were both reported as an
ER_LOCK_DEADLOCK error, but only InnoDB deadlocks rolled back the transaction. Now both
deadlocks roll back the transaction. (Bug #14188793)
• Columns in a PRIMARY KEY must be NOT NULL, but if declared explicitly as NULL produced
no error. Now an error occurs. For example, a statement such as CREATE TABLE t (i INT
NULL PRIMARY KEY) is rejected. The same occurs for similar ALTER TABLE statements. (Bug
#13995622, Bug #66987, Bug #15967545, Bug #16545198)
• Some .pdb files were missing from Windows Zip archive distributions. (Bug #13878021)
• Several issues identified by the Coverity static analysis tool were fixed. Thanks to Jan Staněk and
Honza Horak for the patches. (Bug #70591, Bug #17590095)
• Setting host_cache_size at startup had no effect. (Bug #70552, Bug #17576516)
• MySQL did not compile on OS X 10.9 (Mavericks). (Bug #70542, Bug #17647863)
• For EXPLAIN FOR CONNECTION connection_id, the parser did not permit connection_id
values larger than the maximum signed BIGINT value. The maximum unsigned value now is
permitted. (Bug #70533, Bug #17564492)
• EXPLAIN FOR CONNECTION reported no error if the connection ID belonged to no connection
thread. (Bug #70532, Bug #17564493)
• In some cases, range conditions over indexes defined on column prefixes returned incomplete
result sets. (For example, SELECT ... WHERE 'abcdef1' < col_name AND col_name <
'abcdef9', where the index on col_name indexed only the first 6 characters.) (Bug #70341, Bug
#17458273)
• InnoDB full-text searches failed to find records within transactions that included savepoints. (Bug
#70333, Bug #17458835)
• Incorrect reference counting in the range optimizer module resulted in potential for missing or
duplicate rows in the query result set. (Bug #70236, Bug #17405466)
• If asked to upgrade a server that was running without InnoDB enabled, mysql_upgrade issued
complaints about InnoDB tables not existing (tables that will not exist unless InnoDB is available).
(Bug #70152, Bug #17361912)
• With the thread pool plugin enabled, the PROCESSLIST_USER and PROCESSLIST_HOST columns
of the threads Performance Schema table were always NULL for client sessions. Also, for the main
thread, those columns were not NULL but set to a user account.
Note
As part of the bug fix implementation, Performance Schema instrumentation
for the thread pool plugin was changed to use thread_pool, not sql.
(Bug #70028, Bug #17310065, Bug #17049691)
255
MySQL 5.7 Release Notes
• Performance Schema instrumentation overhead was reduced for frequent connect/disconnect
operations. (Bug #70018, Bug #17310878)
• Full-text search on InnoDB tables failed on searches for words containing apostrophes when using
boolean operators.
The innodb_ft_max_token_size maximum value was incorrectly defined as 252, which is the
maximum byte length. The maximum innodb_ft_max_token_size value is now 84, which is the
maximum character length. (Bug #69932, Bug #17276125)
• COUNT(DISTINCT) should not count NULL values, but they were counted when the optimizer used
Loose Index Scan. (Bug #69841, Bug #17222452)
• InnoDB deadlock caused transaction rollback but did not release metadata locks, blocking
concurrent DDL on the transaction tables until the connection that got the deadlock issued an explicit
COMMIT or ROLLBACK. (Bug #69668, Bug #17054007)
• In debug builds, static initialization code could call DBUG functions before the DBUG subsystem was
initialized. (Bug #69653, Bug #17063675)
• Reads of Geometry values within a stored program could read already-freed memory and produce
incorrect results. (Bug #69517, Bug #16985214)
• Specifying the same directory with multiple instances of --ignore-db-dir caused a server exit.
(Bug #69441, Bug #16944177)
• For queries that qualify to be written to the slow query log, the check whether the log is enabled now
occurs earlier, reducing overhead.
Also, when log_throttle_queries_not_using_indexes is specified at server startup, a value
is now required. Previously, it was incorrectly treated as optional. (Bug #69420, Bug #16924125)
• Some INSERT INTO ... SELECT ... FROM statements were slow unless the
tmp_table_size and max_heap_table_size system variables were set large enough to permit
the temporary table used for query processing to be stored in the MEMORY storage engine. (Bug
#69368, Bug #16894092)
• Missing va_end() calls were added to logging and UCS2 code. Thanks to Jan Staněk for the patch.
(Bug #68896, Bug #16725769)
• ER_TRUNCATED_WRONG_VALUE (truncated value) errors for DECIMAL values failed to show the
erroneous input value. (Bug #68745, Bug #16552002)
• For queries of the form UPDATE ... WHERE unique_key ORDER BY ... LIMIT ...,
incorrect rows could be updated. Unique keys permit multiple NULL values, but the optimizer did not
always consider all of them. (Bug #68656, Bug #16482467)
• Within a stored function or trigger, occurrence of an ER_LOCK_WAIT_TIMEOUT error caused failure
to execute a condition handler. (Bug #67947, Bug #16041903)
• With a NULL literal in a particular parameter position, IFNULL(), COALESCE(), and CASE returned a
signed value when they should return an unsigned value. (Bug #65976, Bug #14359340)
• The server uses the ethernet hardware address for UUID generation, but made assumptions about
the names of ethernet devices rather than querying the system for their names. Thanks to Honza
Horak for the patch. (Bug #63055, Bug #13548252)
• Host names in grant tables are stored in lowercase, but mysql_install_db could fail to observe
this convention, leading to accounts that could not be dropped with DROP USER. (Bug #62255, Bug
#12917164, Bug #62254, Bug #12917151)
256
MySQL 5.7 Release Notes
• If one connection changed its default database and simultaneously another connection executed
SHOW PROCESSLIST, the second connection could access invalid memory when attempting to
display the first connection's default database. memory. (Bug #58198, Bug #11765252)
• At server shutdown, a race condition between the main thread and the shutdown thread could cause
server failure. (Bug #56666, Bug #11763896)
• Fixed a potential problem with the MySQL string function strmov(). Its behavior with respect
to overlap of source and destination previously depended on native support for stpcpy(). (Bug
#48864, Bug #17429539)
• For a column declared as a PRIMARY KEY, the MySQL sometimes unnecessarily added a DEFAULT
clause. For example, for CREATE TABLE t (a INT, PRIMARY KEY(a)), a DEFAULT 0 clause
was added, whereas with CREATE TABLE t (a INT PRIMARY KEY), it was not. (Bug #36723,
Bug #11748566)
• Views containing ORDER BY integer could result in errors at view evaluation time. Consider these
view definitions, which use ORDER BY with an ordinal number:
CREATE VIEW v1 AS SELECT x, y, z FROM t ORDER BY 2;
CREATE VIEW v2 AS SELECT x, 1, z FROM t ORDER BY 2;
In the first case, ORDER BY 2 refers to a named column y. In the second case, it refers to a
constant 1. For queries that select from either view fewer than 2 columns (the number named in the
ORDER BY clause), an error occurred if the server evaluated the view using the MERGE algorithm.
Examples:
mysql> SELECT x FROM v1;
ERROR 1054 (42S22): Unknown column '2' in 'order clause'
mysql> SELECT x FROM v2;
ERROR 1054 (42S22): Unknown column '2' in 'order clause'
To handle view definitions like this, the server now writes them differently into the .frm file that
stores the view definition. This difference is visible with SHOW CREATE VIEW. Previously, the .frm
file contained this for the ORDER BY 2 clause:
For v1: ORDER BY 2
For v2: ORDER BY 2
Now, the .frm file contains this:
For v1: ORDER BY `t`.`y`
For v2: ORDER BY ''
That is, for v1, 2 is replaced by a reference to the name of the column referred to. For v2, 2 is
replaced by a constant string expression (ordering by a constant has no effect, so ordering by any
constant will do).
If you experience view-evaluation errors such as just described, drop and recreate the view so
that the .frm file contains the updated view representation. Alternatively, for views like v2 that
order by a constant value, drop and recreate the view with no ORDER BY clause. (Bug #28695, Bug
#11746789)
• Killing a query that is performing a filesort operation resulted in an ER_SERVER_SHUTDOWN
(Server shutdown in progess) error. (Bug #18256, Bug #11745656)
257
MySQL 5.7 Release Notes
Changes in MySQL 5.7.2 (2013-09-21, Milestone 12)
Note
This is a milestone release, for use at your own risk. Upgrades between
milestone releases (or from a milestone release to a GA release) are not
supported. Significant development changes take place in milestone releases
and you may encounter compatibility issues, such as data format changes that
require attention in addition to the usual procedure of running mysql_upgrade.
For example, you may find it necessary to dump your data with mysqldump
before the upgrade and reload it afterward.
• Authentication Notes
• Compilation Notes
• Diagnostics Notes
• Logging Notes
• Performance Schema Notes
• RPM Notes
• Security Notes
• Semisynchronous Replication Notes
• Trigger Notes
• Functionality Added or Changed
• Bugs Fixed
Authentication Notes
• Incompatible Change: Previously, account rows in the mysql.user table could have an empty
plugin column value. In this case, the server authenticated such an account using either the
mysql_native_password or mysql_old_password plugin, depending on whether the password
hash value in the Password column used native hashing or the older pre-4.1 hashing method. With
the deprecation of old-format password hashes in MySQL 5.6.5, this heuristic for deciding which
authentication plugin to use is unnecessary and it is desirable that user table rows always specify
explicitly which authentication plugin applies.
To that end, the plugin column is now defined to be non-NULL with a default value of
'mysql_native_password', and associated server operations require the column to be
nonempty. In conjunction with this plugin column definition modification, several other changes
have been made:
• The --default-authentication-plugin command-line option is reimplemented as the
default_authentication_plugin system variable. Its use at server startup is unchanged,
but now the default plugin value can be examined at runtime using SHOW VARIABLES or SELECT
@@default_authentication_plugin. The variable is read only and cannot be changed at
runtime.
• When mysql_install_db is run, it invokes the server to initialize the mysql database. The
server now assigns every user table row a nonempty plugin column value. The value is
'mysql_native_password' unless the default_authentication_plugin system variable
is set otherwise at server startup.
258
MySQL 5.7 Release Notes
• mysql_upgrade checks user table rows and, for any row with an empty plugin column, sets
that column to 'mysql_native_password' or 'mysql_old_password' depending on the
hash format of the Password column value.
• At startup, and at runtime when FLUSH PRIVILEGES is executed, the server checks user table
rows. For any row with an empty plugin column, the server writes a warning to the error log of
this form:
[Warning] User entry 'user_name'@'host_name' has an empty plugin
value. The user will be ignored and no one can login with this user
anymore.
To address this issue, execute mysql_upgrade.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate the plugin column change into the mysql system database
and assign the appropriate nonempty plugin value to any empty plugin column values. However,
because the server now checks for and disables accounts with empty plugin column values, it is
necessary to upgrade as follows.
If you plan to to upgrade using the data directory from your existing MySQL installation:
1. Stop the old server
2. Upgrade the MySQL binaries in place (replace the old binaries with the new ones)
3. Restart the server with the --skip-grant-tables option to disable privilege checking
4. Run mysql_upgrade to upgrade the system tables
5. Restart the server normally (without --skip-grant-tables)
If you plan to upgrade by reloading a dump file generated from your existing MySQL installation:
1. To generate the dump file, run mysqldump without the --flush-privileges option
2. Stop the old server
3. Upgrade the MySQL binaries in place (replace the old binaries with the new ones)
4. Restart the server with the --skip-grant-tables option to disable privilege checking
5. Reload the dump file (mysql < dump_file)
6. Run mysql_upgrade to upgrade the system tables
7. Restart the server normally (without --skip-grant-tables)
mysql_upgrade runs by default as the MySQL root user. For the preceding procedures, if the
root password is expired when you run mysql_upgrade, you will see a message that your
password is expired and that mysql_upgrade failed as a result. To correct this, reset the root
password to unexpire it and run mysql_upgrade again:
shell> mysql -u root -p
Enter password: **** <- enter root password here
mysql> SET PASSWORD = PASSWORD('root-password');
mysql> quit
shell> mysql_upgrade -p
Enter password: **** <- enter root password here
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MySQL 5.7 Release Notes
The password-resetting statement normally does not work if the server is started with --skipgrant-tables, but the first invocation of mysql_upgrade flushes the privileges, so when you run
mysql, the statement is accepted.
Compilation Notes
• Work was done to clean up the source code base, including: Removing unneeded CMake checks;
removing unused macros from source files; reorganizing header files to reduce the number of
dependencies and make them more modular, removing function declarations without definitions,
replacing locally written functions with equivalent functions from industry-standard libraries.
Diagnostics Notes
• Incompatible Change: Per the SQL standard, nondiagnostic statements should clear the
diagnostics area when they begin executing. Previously, MySQL differed from this in that some
nondiagnostic statements did not do this. MySQL now follows the SQL standard, which affects the
content of the diagnostics area for some statements. Consequently, the result from statements such
as SHOW WARNINGS that display the diagnostics area now differs somewhat:
• The previous behavior: SHOW WARNINGS displays information about the conditions (errors,
warnings, and notes) resulting from the most recent statement in the current session that
generated messages. It shows nothing if the most recent statement used a table and generated no
messages. (That is, statements that use a table but generate no messages clear the message list.)
Statements that do not use tables and do not generate messages have no effect on the message
list.
• The new behavior: SHOW WARNINGS displays information about the conditions resulting from
execution of the most recent nondiagnostic statement in the current session.
The result from other diagnostic statements is affected similarly (SHOW ERRORS, GET
DIAGNOSTICS).
The following example demonstrates the difference in behavior.
Previously:
mysql> DROP TABLE test.no_such_table;
ERROR 1051 (42S02): Unknown table 'test.no_such_table'
mysql> SELECT @@warning_count;
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW WARNINGS;
+-------+------+------------------------------------+
| Level | Code | Message
|
+-------+------+------------------------------------+
| Error | 1051 | Unknown table 'test.no_such_table' |
+-------+------+------------------------------------+
1 row in set (0.00 sec)
Here, the SELECT statement does not use tables and does not generate messages, so it does not
change the diagnostics area. Consequently, SHOW WARNINGS output pertains to the DROP TABLE
statement.
Now:
mysql> DROP TABLE test.no_such_table;
ERROR 1051 (42S02): Unknown table 'test.no_such_table'
mysql> SELECT @@warning_count;
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW WARNINGS;
Empty set (0.00 sec)
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MySQL 5.7 Release Notes
Here, the SELECT statement clears the diagnostics area because it is a nondiagnostic statement.
Consequently, SHOW WARNINGS output pertains to the SELECT statement (and is empty because the
SELECT produces no messages).
An implication of this change in diagnostics area handling is that if you expect to display the warning
count as well as the list of messages, you should list the messages first because selecting the
warning_count value clears the message list. Alternatively, use SHOW COUNT(*) WARNINGS to
display the count; this is recognized as a diagnostic statement and does not clear the diagnostics
area. Similar considerations apply to use of error_count.
For compliance with the SQL standard, which states that diagnostics statements are not preparable,
MySQL no longer supports the following as prepared statements:
• SHOW WARNINGS, SHOW COUNT(*) WARNINGS
• SHOW ERRORS, SHOW COUNT(*) ERRORS
• Statements containing any reference to the warning_count or error_count system variable.
In other words, those statements are now treated, in terms of preparability, the same as GET
DIAGNOSTICS, which was already not preparable.
Logging Notes
• Incompatible Change: Several changes have been made to provide more logging control and more
informative log messages:
• The log_error_verbosity system variable now controls verbosity of the server in writing error,
warning, and note messages to the error log. Permitted values are 1 (errors only), 2 (errors and
warnings), 3 (errors, warnings, and notes), with a default of 3.
log_error_verbosity is preferred over, and should be used instead of, the older
log_warnings system variable. See the description of log_warnings for information about how
that variable relates to log_error_verbosity (Server System Variables). The log_warnings
system variable and --log-warnings command-line option now are deprecated and will be
removed in a future MySQL release.
Note
The effective default verbosity is different now. The previous default
(log_warnings=1) corresponds to log_error_verbosity=2, but the
default log_error_verbosity is 3. To achieve a logging level similar to
the previous default, set log_error_verbosity=2.
• Default server verbosity is less when invoked with the --bootstrap option (such as is done by
mysql_install_db): Only errors are written during the installation process so that they are less
likely to be overlooked by the installer.
• The log_timestamps system variable has been introduced for control of the timestamp time
zone of messages written to the error log, and of general query log and slow query log messages
written to files. (It does not affect the time zone of general query log and slow query log messages
written to log tables, but rows retrieved from those tables can be converted from the local system
time zone to any desired time zone with CONVERT_TZ() or by setting the session time_zone
system variable.)
Note
The default timestamp time zone is different now (UTC rather than
the local system time zone). To restore the previous default, set
log_timestamps=SYSTEM.
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MySQL 5.7 Release Notes
• The format of timestamps has changed for messages written to the error log, and for general query
log and slow query log messages written to files. Timestamps are written using ISO 8601 / RFC
3339 format: YYYY-MM-DDThh:mm:ss.uuuuuu plus a tail value of Z signifying Zulu time (UTC) or
±hh:mm (an offset from UTC). In addition, for the general query log file, timestamps are included in
every message, not just when the second changes.
The format of timestamps has also changed for messages written to the general query log and
slow query log tables (mysql.general_log, mysql.slow_log), which now include fractional
seconds. (The column type for timestamps has changed from TIMESTAMP to TIMESTAMP(6).)
• Previously, the ID included in error log messages was the mysqld process ID. Now the ID is that
of the thread within mysqld responsible for writing the message. This is more informative with
respect to which part of the server produced the message. It is also more consistent with general
query log and slow query log messages, which include the connection thread ID.
For information about log output destinations, see Selecting General Query and Slow Query Log
Output Destinations. For information about specific logs, see The Error Log, The General Query Log,
and The Slow Query Log.
Performance Schema Notes
• The Performance Schema now provides tables that expose replication information. This is similar to
the information available from the SHOW SLAVE STATUS statement, but representation in table form
is more accessible and has usability benefits:
• SHOW SLAVE STATUS output is useful for visual inspection, but not so much for programmatic
use. By contrast, using the Performance Schema tables, information about slave status can be
searched using general SELECT queries, including complex WHERE conditions, joins, and so forth.
• Query results can be saved in tables for further analysis, or assigned to variables and thus used in
stored procedures.
• The replication tables provide better diagnostic information. For multi-threaded slave
operation, SHOW SLAVE STATUS reports all coordinator and worker thread errors using the
Last_SQL_Errno and Last_SQL_Error fields, so only the most recent of those errors is visible
and information can be lost. The replication tables store errors on a per-thread basis without loss
of information.
• The last seen transaction is visible in the replication tables on a per-worker basis. This is
information not avilable from SHOW SLAVE STATUS.
• Developers familiar with the Performance Schema interface can extend the replication tables to
provide additional information by adding rows to the tables.
These tables provide replication information:
• replication_connection_configuration and replication_connection_status
indicate the configuration parameters used by the slave for connecting to the master and the
status of the connection.
• replication_execute_configuration and replication_execute_status indicate, for
aspects of transaction execution on the slave not specific to any given thread, the configuration
parameters and the current execution status.
• replication_execute_status_by_coordinator and
replication_execute_status_by_worker contain thread-specific transaction execution
information, either about the SQL thread (for a single-threaded slave), or about the coordinator and
worker threads (for a multi-threaded slave).
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MySQL 5.7 Release Notes
If the slave is multi-threaded, the SQL thread is the coordinator for worker threads. In this case,
the Last_SQL_Error field of SHOW SLAVE STATUS output now shows exactly what the
Last_Error_Message column in the replication_execute_status_by_coordinator
Performance Schema table shows. The field value is modified to suggest that
there may be more failures in the other worker threads which can be seen in the
replication_execute_status_by_worker table that shows each worker thread's status.
For more information, see Performance Schema Replication Tables.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
• The Performance Schema now instruments stored program execution and aggregates statistics for
them. This includes stored procedures, stored functions, triggers, and Event Scheduler events.
These specific changes were implemented:
• The setup_instruments table has new instruments. The statement/scheduler/event
instrument tracks all events executed by the Event Scheduler. Instruments with names of the
form statement/sp/program_instruction track internal instructions executed by stored
programs.
• The setup_objects table OBJECT_TYPE column now permits values of 'EVENT',
'FUNCTION', 'PROCEDURE', 'TABLE', or 'TRIGGER', not just 'TABLE'.
• Statement event tables (events_statements_current, events_statements_history, and
events_statements_history_long) now have a NESTING_LEVEL column that indicates the
event nesting level.
• The performance_schema_max_program_instances and
performance_schema_max_statement_stack system variables configure the maximum
number of stored programs and the maximum depth of nested stored program calls for which the
Performance Schema maintains statistics.
• The Performance_schema_program_lost and
Performance_schema_nested_statement_lost status variables indicate the number of
stored programs for which statistics were lost, and the number of stored program statements for
which statistics were lost.
• The events_statements_summary_by_program summary table aggregates statement events
per stored program.
For more information, see Event Pre-Filtering, and Statement Summary Tables.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
• The Performance Schema now instruments memory usage and aggregates memory usage statistics,
detailed by these factors:
• Type of memory used (various caches, internal buffers, and so forth)
• Thread, account, user, host indirectly performing the memory operation
The Performance Schema instruments the following aspects of memory use
• Memory sizes used
• Operation counts
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MySQL 5.7 Release Notes
• Low and high water marks
Memory sizes help to understand or tune the memory consumption of a server.
Operation counts help to understand or tune the overall pressure the server is putting on the memory
allocator, which has an impact on performance. Allocating a single byte one million times is not the
same as allocating one million bytes a single time; tracking both sizes and counts can expose the
difference.
Low and high water marks are critical to detect workload spikes, overall workload stability, and
possible memory leaks.
These specific changes were implemented:
• The setup_instruments table now has memory instruments. These have names of the form
memory/component/instrument_name. Memory instrumentation is disabled by default.
• The performance_schema_max_memory_classes system variable configures the maximum
number of memory instruments.
• The Performance_schema_memory_classes_lost status variable indicates the number of
times a memory instrument could not be loaded.
• Several summary tables aggregate memory-related events.
For more information, see Memory Summary Tables.
If you upgrade to this MySQL release from an earlier version, you must run mysql_upgrade (and
restart the server) to incorporate these changes into the performance_schema database.
RPM Notes
• It was not possible to upgrade a community RPM to a commercial RPM using rpm -uvh or yum
localupdate. To deal with this, the RPM spec file has been updated in MySQL 5.7.2, which has
the following consequences:
• For a non-upgrade installation (no existing MySQL version installed), it possible to install MySQL
using yum.
• For upgrades, it is necessary to clean up any earlier MySQL installations. In effect, the update is
performed by removing the old installations and installing the new one.
Additional details follow.
For a non-upgrade installation of MySQL 5.7.2, it is possible to install using yum:
shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm
For upgrades to MySQL 5.7.2, the upgrade is performed by removing the old installation and
installing the new one. To do this, use the following procedure:
1. Remove the existing 5.7.X installation. OLDVERSION is the version to remove.
shell> rpm -e MySQL-server-OLDVERSION.glibc23.i386.rpm
Repeat this step for all installed MySQL RPMs.
2. Install the new version. NEWVERSION is the version to install.
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MySQL 5.7 Release Notes
shell> rpm -ivh MySQL-server-NEWVERSION.glibc23.i386.rpm
Alternatively, the removal and installation can be done using yum:
shell> yum remove MySQL-server-OLDVERSION.glibc23.i386.rpm
shell> yum install MySQL-server-NEWVERSION.glibc23.i386.rpm
(Bug #16445097, Bug #16445125, Bug #16587285)
Security Notes
• Platform availability, usability, and security of mysql_secure_installation has been improved.
Previously, this program was a shell script available for Unix and Unix-like systems. It has been
converted to a binary executable program (written in C++) that is available on all platforms.
Implementation as a C++ program permits mysql_secure_installation to connect directly
to the MySQL server using the client/server protocol, rather than by invoking mysql to do so and
communicating with mysql using temporary files.
This reimplementation of mysql_secure_installation is feature-compatible with previous
versions, but the following usability improvements have been made:
• The validate_password plugin can be used for password strength checking.
• Standard MySQL options such as --host and --port are supported on the command line and in
option files.
For more information, see mysql_secure_installation — Improve MySQL Installation
Security. For more information about validate_password, see The Password Validation Plugin.
Semisynchronous Replication Notes
• Replication: Semisynchronous replication master servers now use a different wait point by default
in communicating wih slaves. This is the point at which the master waits for acknowledgment of
transaction receipt by a slave before returning a status to the client that committed the transaction.
The wait point is controlled by the new rpl_semi_sync_master_wait_point system variable.
These values are permitted:
• AFTER_SYNC (the default): The master writes each transaction to its binary log and the slave, and
syncs the binary log to disk. The master waits for slave acknowledgment of transaction receipt
after the sync. Upon receiving acknowledgment, the master commits the transaction to the storage
engine and returns a result to the client, which then can proceed.
• AFTER_COMMIT: The master writes each transaction to its binary log and the slave, syncs
the binary log, and commits the transaction to the storage engine. The master waits for slave
acknowledgment of transaction receipt after the commit. Upon receiving acknowledgment, the
master returns a result to the client, which then can proceed.
For older versions of MySQL, semisynchronous master behavior is equivalent to a setting of
AFTER_COMMIT.
The replication characteristics of these settings differ as follows:
• With AFTER_SYNC, all clients see the committed transaction at the same time: After it has been
acknowledged by the slave and committed to the storage engine on the master. Thus, all clients
see the same data on the master.
In the event of master failure, all transactions committed on the master have been replicated to the
slave (saved to its relay log). A crash of the master and failover to the slave is lossless because
the slave is up to date.
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MySQL 5.7 Release Notes
• With AFTER_COMMIT, the client issuing the transaction gets a return status only after the server
commits to the storage engine and receives slave acknowledgment. After the commit and before
slave acknowledgment, other clients can see the committed transaction before the committing
client.
If something goes wrong such that the slave does not process the transaction, then in the event
of a master crash and failover to the slave, it is possible that such clients will see a loss of data
relative to what they saw on the master.
The new wait point is a behavior change, but requires no reconfiguration. The change does introduce
a version compatibility constraint because it increments the semisynchronous interface version:
Servers for MySQL 5.7.2 and up do not work with semisynchronous replication plugins from older
versions, nor do servers from older versions work with semisynchronous replication plugins for
MySQL 5.7.2 and up.
Trigger Notes
• Previously, a table could have at most one trigger for each combination of trigger event (INSERT,
UPDATE, DELETE) and action time (BEFORE, AFTER). This limitation has been lifted and multiple
triggers are permitted. Along with that change, several additional modifications were made:
• By default, triggers for each combination of trigger event and action time execute in the order
they were created. To make it possible to specify trigger activation order, CREATE TRIGGER now
supports FOLLOWS and PRECEDES clauses. Each clause takes the name of an existing trigger that
has the same trigger event and action time.
• The ACTION_ORDER column in the INFORMATION_SCHEMA.TRIGGERS table is no longer 0 but an
integer greater than zero that indicates the order in which triggers activate.
• Creation time for triggers is now maintained, as a TIMESTAMP(2) value (with a fractional part in
hundredths of seconds):
• The CREATED column in the TRIGGERS table is no longer NULL, for triggers created as of
MySQL 5.7.2.
• The same is true for the Created column of SHOW TRIGGERS output, and for the (new)
Created column of SHOW CREATE TRIGGER output.
• The tbl_name.TRG file that stores trigger information for table tbl_name now contains a
created line with trigger creation times.
For additional information, see Using Triggers, CREATE TRIGGER Syntax, SHOW CREATE
TRIGGER Syntax, SHOW TRIGGERS Syntax, The INFORMATION_SCHEMA TRIGGERS Table,
and Table Trigger Storage.
• If run against a table that has triggers, mysql_upgrade and CHECK TABLE ... FOR UPGRADE
display this warning for each trigger created before MySQL 5.7.2:
Trigger db_name.tbl_name.trigger_name does not have CREATED attribute.
The warning is informational only. No change is made to the trigger.
These changes have implications for backups, upgrades, and downgrades, as described following.
For brevity, “multiple triggers” here is shorthand for “multiple triggers that have the same trigger
event and action time.”
Backup and restore. mysqldump dumps triggers in activation order so that when the dump file
is reloaded, triggers are re-created in the same activation order. However, if a mysqldump dump
file contains multiple triggers for a table that have the same trigger event and action time, an error
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MySQL 5.7 Release Notes
occurs for attempts to load the dump file into an older server that does not support multiple triggers.
(See the downgrading notes for a workaround; you can convert triggers to be compatible with older
servers.)
Upgrades. Suppose that you upgrade an old server that does not support multiple triggers to MySQL
5.7.2 or newer. If the new server is a replication master and has old slaves that do not support
multiple triggers, an error occurs on those slaves if a trigger is created on the master for a table that
already has a trigger with the same trigger event and action time. To avoid this problem, upgrade the
slaves first, then upgrade the master.
Downgrades. If you downgrade a server that supports multiple triggers to an older version that does
not, the downgrade has these effects:
• For each table that has triggers, all trigger definitions remain in the .TRG file for the table.
However, if there are multiple triggers with the same trigger event and action time, the server
executes only one of them when the trigger event occurs. For information about .TRG files, see
Table Trigger Storage.
• If triggers for the table are added or dropped subsequent to the downgrade, the server rewrites
the table's .TRG file. The rewritten file retains only one trigger per combination of trigger event and
action time; the others are lost.
To avoid these problems, modify your triggers before downgrading. For each table that has multiple
triggers per combination of trigger event and action time, convert each such set of triggers to a single
trigger as follows:
1. For each trigger, create a stored routine that contains all the code in the trigger. Values accessed
using NEW and OLD can be passed to the routine using parameters. If the trigger needs a single
result value from the code, you can put the code in a stored function and have the function return
the value. If the trigger needs multiple result values from the code, you can put the code in a
stored procedure and return the values using OUT parameters.
2. Drop all triggers for the table.
3. Create one new trigger for the table that invokes the stored routines just created. The effect for
this trigger is thus the same as the multiple triggers it replaces.
References: See also: Bug #28803, Bug #11746800, Bug #37567, Bug #11748861.
Functionality Added or Changed
• Incompatible Change: Previously, the Performance Schema statement instrumentation did
not include statements executed on a slave replication server. To address this, a new abstract
instrument, statement/rpl/relay_log, has been added to the setup_instruments table.
This instrument is used during the early stages of replicated statement classification before the exact
statement type is known. (Bug #16750433, Bug #17271055)
• Incompatible Change: Previously, the main loop responsible for accepting client connections also
performed initialization of data structures related to each connection. These initialization tasks now
are delegated to worker threads to minimize work done by the accept loop and maximize connection
acceptance rate.
As a result of this change, the bind_address, thread_cache_size, and thread_handling
system variables are no longer visible to the embedded server (libmysqld). Similarly, the
Slow_launch_threads and Threads_cached status variables are not meaningful in the
embedded server. These variables are no longer visible within the embedded server and embedded
applications that rely on these variables should be modified accordingly. (Bug #62288, Bug
#12951536, Bug #62284, Bug #12951595, Bug #62283, Bug #12951605)
• Incompatible Change: The unused --basedir and --datadir options for mysql_upgrade
have been removed.
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MySQL 5.7 Release Notes
• Important Change; Partitioning: It is now possible to check and to repair partitions which contain
duplicate key violations. This is implemented by allowing the IGNORE keyword in ALTER TABLE
statements using the CHECK PARTITION or REPAIR PARTITION option. The keyword has the
following effects on the behavior of these statements:
• ALTER IGNORE TABLE ... REPAIR PARITION removes all rows that cannot be moved due to
the presence of duplicate keys.
• ALTER IGNORE TABLE ... CHECK PARTITION reports the contents of all columns in the
partitioning expression for each row.
Note
Support for the IGNORE keyword is removed in MySQL 5.7.4.
(Bug #16900947)
• Important Change; Replication: By default, when promoting integers from a smaller type on the
master to a larger type on the slave (for example, from a SMALLINT column on the master to a
BIGINT column on the slave), the promoted values are treated as though they are signed. Now
in such cases it is possible to modify or override this behavior using one or both of ALL_SIGNED,
ALL_UNSIGNED in the set of values specified for the slave_type_conversions server system
variable. For more information, see Row-based replication: attribute promotion and demotion, as well
as the description of the variable. (Bug #15831300)
• Performance; InnoDB: Multi-version concurrency control (MVCC) in InnoDB requires that each
transaction using MVCC be assigned a read view. To improve InnoDB read-only and read-write
performance, read view creation has been optimized by reducing mutex contention.
• Performance; InnoDB: An sx-lock, a new type of rw-lock, optimizes concurrency and improves
scalability for read-write workloads. sx-locks reduce locking contention for B-tree index operations
by providing write access while permitting inconsistent reads by other threads.
• Performance; InnoDB: Memory for transaction instances (trx_t) is now allocated in configurable
sized blocks that are a multiple of transaction instance size. Transaction instances are also placed
in a priority queue and ordered by their address in memory so that when instances are allocated
from the pool, they are close together. This enhancement reduces the cost incurred by iterating over
transactions instances when allocating instances from the pool.
• InnoDB: innochecksum functionality has been enhanced with new options and extended
capabilities. See innochecksum — Offline InnoDB File Checksum Utility. (Bug #16945722)
• InnoDB: A new CMake option, WITH_INNODB_EXTRA_DEBUG, has been added that enables
additional InnoDB debug checks. WITH_INNODB_EXTRA_DEBUG can only be enabled when the
WITH_DEBUG option is also enabled. (Bug #16821155)
• InnoDB: When building MySQL from source, you can now define the type of mutex used by InnoDB
using the new MUTEX_TYPE CMake option.
• InnoDB: Refactored mutex code makes selecting the appropriate mutex easier and allows multiple
mutex types to be combined in the same instance. The refactored code also removes the distinction
between fast_mutex_t and home brew ib_mutex_t types, implements a common interface for
both mutex types, and allows new mutex types to be added in the future. Additionally, mutex code is
decoupled from InnoDB code so that it can be used as a library, and a “PolicyMutex” interface has
been introduced. The new interface uses static inheritance (templates) for mutex implementation
making it easier to define policies and customize mutex behavior.
• InnoDB: Buffer pool list scans and related batch processing have been optimized to reduce scan
complexity and the number of pages scanned.
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MySQL 5.7 Release Notes
• InnoDB: InnoDB buffer pool dump and load operations have been enhanced. A new system
variable, innodb_buffer_pool_dump_pct, allows you to specify the percentage of most
recently used pages in each buffer pool to read out and dump. When there is other I/O activity being
performed by InnoDB background tasks, InnoDB attempts to limit the number of buffer pool load
operations per second using the innodb_io_capacity setting.
• InnoDB: DML operations (INSERT, UPDATE, DELETE) for temporary tables have been optimized
by turning off redo logging, locking, and change buffering that is not required for temporary tables.
Turning off these functions optimizes temporary table DML operations by reducing associated I/O.
• InnoDB: The limit on concurrent data-modifying transactions is now 96 * 1023 transactions that
generate undo records. As of MySQL 5.7.2, 32 of 128 rollback segments are allocated to non-redo
logs for transactions that modify temporary tables and related objects. This reduces the maximum
number of concurrent data-modifying transactions from 128K to 96K. The 96K limit assumes that
transactions do not modify temporary tables. If all data-modifying transactions also modify temporary
tables, the limit would be 32K concurrent transactions.
• InnoDB: MySQL 5.7.2 introduces a new type of undo log for both normal and compressed temporary
tables and related objects. The new type of undo log is not a redo log, as temporary tables are not
recovered during crash recovery and do not require redo logs. The new undo log resides in the
temporary tablespace. The default temporary tablespace file, ibtmp1, is located in the data directory
by default and is always recreated on server startup. A user defined location for the temporary
tablespace file can be specified by setting innodb_temp_data_file_path. For more information,
see Temporary Table Undo Logs.
• InnoDB: Read-only transactions will no longer be assigned a transaction ID. Conversely, an ID will
only be assigned if a transaction is explicitly tagged as “read-write”, if a transaction has acquired
an X or IX lock on a table, or if a transaction is a read-only transaction writing to a temporary
table. All other transactions are considered “read-only” and are not assigned an ID. Furthermore,
read-only transactions are not tagged as “read-only” unless they are explicitly started with START
TRANSACTION READ ONLY. For transactions without transaction IDs, SHOW ENGINE INNODB
STATUS prints an identifier that is unique but only within the context of the SHOW ENGINE INNODB
STATUS invocation.
• InnoDB: SELECT COUNT(*) FROM t statements now invoke a single handler call to the storage
engine to scan the clustered index and return the row count to the Optimizer. Previously, a row count
was typically performed by traversing a smaller secondary index and invoking a handler call for each
record. A single handler call to the storage engine to count rows in the clustered index improves
SELECT COUNT(*) FROM t performance in most cases. For more information, see Limits on
InnoDB Tables.
• InnoDB: Beginning with MySQL 5.7.2, UPDATE_TIME displays a timestamp value for the last
UPDATE, INSERT, or DELETE performed on InnoDB tables. Previously, UPDATE_TIME displayed a
NULL value for InnoDB tables. For MVCC, the timestamp value reflects the COMMIT time, which is
considered the last update time. Timestamps are not persisted when the server is restarted or when
the table is evicted from the InnoDB data dictionary cache.
• InnoDB: The process for converting a transaction's implicit lock to an explicit lock has been
optimized to improve performance. The optimization reduces lock_sys_t::mutex contention.
• InnoDB: A number of internal debug flags in the InnoDB code could only be set at compilation time
or from a debugger. As a result, a significant amount of diagnostic information was unused. This
enhancement replaces internal debug flags with DBUG labels so that the DBUG package can be
used and printouts from various InnoDB subsystems can be enabled using the mysqld --debug
command line option. See the Debugging a MySQL Server section for information about configuring
MySQL for debugging, creating trace files, and using the mysqld --debug option.
• Partitioning: The following operations are now supported for individual subpartitions as well as
partitions: ANALYZE, CHECK, OPTIMIZE, REPAIR, and TRUNCATE (see ALTER TABLE Partition
Operations).
269
MySQL 5.7 Release Notes
Note
This fix also allows the use of REBUILD with individual subpartitions, even
though this is not actually supported by MySQL, and has no effect. This
issue is addressed in MySQL 5.7.5 and later by disallowing REBUILD with
subpartitions in ALTER TABLE statements.
(Bug #14028340, Bug #65184)
References: See also: Bug #19075411, Bug #73130.
• Replication: Previously, transactions could be applied in parallel only if they did not touch the
same database. However, the MySQL Server uses a lock-based scheduler, which means that it
should be possible to execute in parallel all uncommitted replication threads already in the prepare
phase, without violating consistency. Such parallel execution can now be enabled on the slave
by starting the slave mysqld with --slave-parallel-type=LOGICAL_CLOCK or, if mysqld
is already started, by setting the value of the global system variable slave_parallel_type to
'LOGICAL_CLOCK' on a stopped slave.
When this feature is enabled, each transaction is marked with a logical timestamp. This timestamp
identifies the last transaction committed at the time that the current transaction entered the prepare
stage, and all transactions having the same timestamp can execute in parallel.
To disable this feature without restarting, stop the slave using STOP SLAVE (if it is running as a
slave), issue SET @global-slave_parallel_type='DATABASE', then issue START SLAVE
when you want the slave to resume. You can also disable the feature by restarting the slave mysqld
without the --slave-parallel-type option, or by setting it explicitly to DATABASE. When parallel
execution of preapred transactions is disabled, the slave follows the old behavior and applies in
parallel only those transactions that do not cause changes in the same database.
• Replication: The master dump thread was refactored to reduce lock contention and improve master
throughput. Previously, the dump thread took a lock on the binary log whenever reading an event;
now the lock is held only while reading the position at the end of the last successfully written event.
This means that multiple dump threads can now read concurrently from the binary log file, and that
dump threads can read while clients write to the binary log.
• Support for LinuxThreads has been removed from the source code. LinuxThreads was superseded
by NPTL in Linux 2.6. (Bug #17007529, Bug #72888, Bug #18913935)
• Previously, program options could be specified in full or as any unambiguous prefix. For example,
the --compress option could be given to mysqldump as --compr, but not as --comp because
the latter is ambiguous. Option prefixes are no longer supported; only full options are accepted. This
is because prefixes can cause problems when new options are implemented for programs and a
prefix that is currently unambiguous might become ambiguous in the future. Some implications of this
change:
• The --key-buffer option must now be specified as --key-buffer-size.
• The --skip-grant option must now be specified as --skip-grant-tables.
(Bug #16996656)
• Support for building Apple universal binaries to support PowerPC has been removed from the source
code. (Bug #16959103)
• CMake no longer checks for memmove() or memcpy() because they are standard C library
functions. Also, implementation of the bmove_upp() function was replaced with calls to
memmove(), which may have positive performance implications. (Bug #16839824)
270
MySQL 5.7 Release Notes
• The C API libmysqlclient shared-library .so files now have version 18.1.0 (up from version
18.0.0 used in MySQL 5.5). 18.1.0 can be used as a replacement for 18.0.0. (Bug #16809055, Bug
#59106, Bug #12407476)
• Use of DYNAMIC_ARRAY was reduced, which improves performance of certain range queries by
3-4%. (Bug #16736776, Bug #17030235)
• mysqladmin now supports a --show-warnings option to display warnings resulting from
execution of statements sent to the server. (Bug #16517756)
• mysql_upgrade now verifies that the server version matches the version against which it was
compiled, and exits if there is a mismatch. In addiion, a --version-check option permits
specifying whether to enable version checking (the default), or disable checking if given as --skipversion-checking. (Bug #16500013)
• The following items are deprecated and will be removed in a future MySQL release. Where
alternatives are shown, applications should be updated to use them.
• The ENCODE() and DECODE() functions. Consider using AES_ENCRYPT() and AES_DECRYPT()
instead.
• The INFORMATION_SCHEMA.PROFILING table. Use the Performance Schema instead; see
MySQL Performance Schema.
(Bug #16463921)
• Invoking CMake with -DWITH_AUTHENTICATION_PAM=1 now causes the build to fail (rather than
issue only a warning) if the PAM plugin cannot be built. (Bug #14554639)
• In batch mode, mysql formatted result status messages such as “"Query OK, 1 row affected"” but
did not print them. Now these messages are not formatted. (Bug #69486, Bug #16971432)
• Several inefficiencies were corrected:
• A loop in Item_in_subselect::single_value_transformer() could execute too many
times.
• The myisamchk(), my_test_if_sort_rep(), and recreate_table() functions in MyISAM
code could execute too many times.
Thanks to Po-Chun Chang for the patches to correct these issues. (Bug #69138, Bug #16764131,
Bug #69117, Bug #16751784, Bug #69561, Bug #17007268, Bug #69553, Bug #17001703)
• Plugins can now define and expose floating-point system variables of type double using the
MYSQL_SYSVAR_DOUBLE() and MYSQL_THDVAR_DOUBLE() accessor macros. See Client Plugin
Descriptors. (Bug #68121, Bug #16194302)
• MySQL now supports the use of protocol trace plugins: client-side plugins that implement tracing
of communication between a client and the server that takes place using the client/server protocol.
Protocol trace plugins use the client plugin API.
In MySQL source distributions, a test protocol trace plugin is implemented in the
test_trace_plugin.cc file in the libmysql directory. This can be examined as a guide to
writing other protocol trace plugins.
For more information, see Writing Plugins; in particular, Writing Protocol Trace Plugins.
• To make it easier to see the difference between good and bad execution plans, JSON-format
EXPLAIN output now includes this additional cost information:
• query_cost: The total cost of a query block, whether a top-level query or subquery. For a toplevel SELECT, this should be equal to the Last_query_cost status variable.
271
MySQL 5.7 Release Notes
• sort_cost: The cost of the first sorting operation (GROUP BY or ORDER BY) where and if
filesort is used.
• read_cost: The cost of reading data from each table used in the query block (that is, access
method cost).
• eval_cost: The cost of condition evaluation for each table in the query block.
• prefix_cost: The cost of executing prefix join in the query block; that is, the cost of joining
tables of the query block from the first one to the one (and including it) for which the value is given.
• data_read_per_join: The estimated amount of data processed by the handler interface per
query or subquery execution. This is essentially record width * number of read records.
• rows_produced_per_join/ rows_examined_per_join: The estimated number of records
from the table (per table from the query block) produced or examined per single query block
execution.
• used_columns: The list of columns from the table (per each table in the query block) used for
either read or write in the query.
This cost information is not displayed for INFORMATION_SCHEMA tables.
• EXPLAIN can now be used to obtain the execution plan for an explainable statement executing in a
named connection:
EXPLAIN [options] FOR CONNECTION connection_id;
For example, if you are running a statement in one session that is taking a long time to complete,
using EXPLAIN FOR CONNECTION in another session may yield useful information about the cause
of the delay and help you optimize the statement.
connection_id is the connection identifier, as obtained from the INFORMATION_SCHEMA
PROCESSLIST table or the SHOW PROCESSLIST statement. If you have the PROCESS privilege, you
can specify the identifier for any connection. Otherwise, you can specify the identifier only for your
own connections.
Changes in EXPLAIN output:
• In the output from EXPLAIN FOR CONNECTION, an Extra value of Plan isn't ready yet
means that the optimizer has not finished creating the execution plan for the statement executing
in the named connection. (For JSON-format output, this is indicated by planned: false.)
• In the output from any EXPLAIN used to obtain the execution plan for non-SELECT statements, the
select_type value displays the statement type for affected tables. For example, select_type
is DELETE for DELETE statements.
A new status variable, Com_explain_other, indicates how many EXPLAIN FOR CONNECTION
statements have been executed.
For more information, see EXPLAIN Syntax, and Obtaining Execution Plan Information for a Named
Connection.
• Semi-join LooseScan strategy now can use ref access and applies to a wider range of queries.
Bugs Fixed
• Incompatible Change: When used for an existing MySQL account, the GRANT statement
could produce unexpected results if it included an IDENTIFIED WITH clause that named an
authentication plug differing from the plugin named in the corresponding mysql.user table row.
272
MySQL 5.7 Release Notes
Because IDENTIFIED WITH is intended only for GRANT statements that create a new user, it is now
prohibited if the named account already exists. (Bug #16083276)
• Incompatible Change: It is possible for a column DEFAULT value to be valid for the sql_mode
value at table-creation time but invalid for the sql_mode value when rows are inserted or updated.
Example:
SET sql_mode = '';
CREATE TABLE t (d DATE DEFAULT 0);
SET sql_mode = 'NO_ZERO_DATE,STRICT_ALL_TABLES';
INSERT INTO t (d) VALUES(DEFAULT);
In this case, 0 should be accepted for the CREATE TABLE but rejected for the INSERT. However,
previously the server did not evaluate DEFAULT values used for inserts or updates against the
current sql_mode. In the example, the INSERT succeeds and inserts '0000-00-00' into the DATE
column.
The server now applies the proper sql_mode checks to generate a warning or error at insert or
update time.
A resulting incompatibility for replication if you use statement-based logging
(binlog_format=STATEMENT) is that if a slave is upgraded, a nonupgraded master will execute
the preceding example without error, whereas the INSERT will fail on the slave and replication will
stop.
To deal with this, stop all new statements on the master and wait until the slaves catch up. Then
upgrade the slaves followed by the master. Alternatively, if you cannot stop new statements,
temporarily change to row-based logging on the master (binlog_format=ROW) and wait until
all slaves have processed all binary logs produced up to the point of this change. Then upgrade
the slaves followed by the master and change the master back to statement-based logging. (Bug
#68041, Bug #16078943)
• Important Change; Performance; InnoDB: InnoDB failed to open a tablespace that has multiple
data files. This removes the known limitation that was in MySQL Server 5.6.12. (Bug #17033706,
Bug #69623)
• Important Change; Replication: When the server was running with --binlog-ignore-db and
SELECT DATABASE() returned NULL (that is, there was no currently selected database), statements
using fully qualified table names in dbname.tblname format were not written to the binary log. This
was because the lack of a currently selected database in such cases was treated as a match for any
possible ignore option rather than for no such option; this meant that these statements were always
ignored.
Now, if there is no current database, a statement using fully qualified table names is always written to
the binary log. (Bug #11829838, Bug #60188)
• Performance; InnoDB: A code regression introduced in MySQL 5.6 negatively impacted DROP
TABLE and ALTER TABLE performance. This could cause a performance drop between MySQL
Server 5.5.x and 5.6.x. (Bug #16864741, Bug #69316)
• Performance; InnoDB: When innodb_thread_concurrency is set to a non-zero value, there
was a possibility that all innodb_concurrency_tickets would be released after each row was
read, resulting in a concurrency check after each read. This could impact performance of all queries.
One symptom could be higher system CPU usage. We strongly recommend that you upgrade to
MySQL Server 5.6.13 if you use this setting. This could cause a performance drop between MySQL
Server 5.5.x and 5.6.x. (Bug #68869, Bug #16622478)
• InnoDB; Partitioning: Joins involving partitioned InnoDB tables having one or more BLOB columns
were not always handled correctly. The BLOB column or columns were not required to be join
273
MySQL 5.7 Release Notes
columns, or otherwise to be named or referenced in the statement containing the join, for this issue
to occur. (Bug #16367691)
• InnoDB; Partitioning: Following any query on the INFORMATION_SCHEMA.PARTITIONS
table, InnoDB index statistics as shown in the output of statements such as SELECT * FROM
INFORMATION_SCHEMA.STATISTICS were read from the last partition, instead of from the partition
containing the greatest number of rows. (Bug #11766851, Bug #60071)
References: See also: Bug #16882435, Bug #69179.
• InnoDB; Replication: Trying to update a column, previously set to NULL, of an InnoDB table with
no primary key caused replication to fail on the slave with Can't find record in 'table'.
Note
This issue was inadvertently reintroduced in MySQL 5.6.6, and fixed again in
MySQL 5.6.12.
(Bug #11766865, Bug #60091)
References: See also: Bug #16566658.
• InnoDB: In Windows 64-bit debug builds, read view COPY_TRX_IDS would report a “vector
subscript out of range” error to standard error output. (Bug #17320056)
• InnoDB: When logging the delete-marking of a record during online ALTER TABLE...ADD
PRIMARY KEY, InnoDB writes the transaction ID to the log as it was before the deletion or deletemarking of the record. When doing this, InnoDB would overwrite the DB_TRX_ID field in the original
table, which could result in locking issues. (Bug #17316731)
• InnoDB: An assertion failure would occur while searching an index tree and traversing multiple
levels where a block is accessed or pinned at each level. (Bug #17315967)
• InnoDB: The row_sel_sec_rec_is_for_clust_rec function would incorrectly prepare to
compare a NULL column prefix in a secondary index with a non-NULL column in a clustered index.
(Bug #17312846)
• InnoDB: An incorrect purge would occur when rolling back an update to a delete-marked record.
(Bug #17302896)
• InnoDB: The assertion ut_ad(oldest_lsn <= cur_lsn) in file buf0flu.cc failed because the
current max LSN would be retrieved from the buffer pool before the oldest LSN. (Bug #17252421)
• InnoDB: InnoDB memcached add and set operations would perform more slowly than SQL
INSERT operations. (Bug #17214191)
• InnoDB: As commented in log0log.h, old_lsn and old_buf_free should only be compiled
when UNIV_LOG_DEBUG is enabled. (Bug #17160270, Bug #69724)
• InnoDB: When started in read-only mode, InnoDB would assert on a savepoint. (Bug #17086428)
• InnoDB: Before dropping an index, a check is performed to ensure the index root page is free. If
the index root page is free, dropping activity is avoided. A transaction would be initialized before
the check is performed. If the check evaluated to true, the initialized transaction would be left in a
dangling state. (Bug #17076822)
• InnoDB: Adding a foreign key with a constraint name that included the string “_ibfk_” caused
InnoDB to create a duplicate constraint with a generated internal name. The generated internal
name could also collide with an existing user-defined constraint of the same name, causing a
duplicate key error. (Bug #17076737, Bug #69693, Bug #17076718, Bug #69707)
• InnoDB: An InnoDB monitor test would raise an assertion in ha_innodb.cc due to a mutex
conflict. (Bug #17027249)
274
MySQL 5.7 Release Notes
• InnoDB: In debug builds, the trx_sys->rw_max_trx_id variable would sometimes be reversed
resulting in an inconsistent CLUST_INDEX_SIZE value. (Bug #17026780)
• InnoDB: The ha_innobase::clone function would incorrectly assert that a thread cannot clone a
table handler that is used by another thread, and that the original table handler and the cloned table
handler must belong to the same transaction. The incorrect assertions have been removed. (Bug
#17001980)
• InnoDB: A regression introduced in the fix for Bug #14606334 would cause crashes on startup
during crash recovery. (Bug #16996584)
• InnoDB: Rolling back an INSERT after a failed BLOB write would result in an assertion failure. The
assertion has been modified to allow NULL BLOB pointers if an error occurs during a BLOB write.
(Bug #16971045)
• InnoDB: SHOW ENGINE INNODB STATUS output referenced a thread in hex format (example:
thread handle 0x880), whereas the same thread was referenced in the SHOW ENGINE INNODB
STATUS transaction list in decimal format (example: thread id 2176). (Bug #16934269, Bug
#69437)
• InnoDB: A full-text search using the IN BOOLEAN MODE modifier would result in an assertion
failure. (Bug #16927092)
References: This issue is a regression of: Bug #16516193.
• InnoDB: When CHECK TABLE found a secondary index that contained the wrong number of entries,
it would report an error but not mark the index as corrupt. CHECK TABLE now marks the index as
corrupt when this error is encountered, but only the index is marked as corrupt, not the table. As a
result, only the index becomes unusable until it is dropped and rebuilt. The table is unaffected. (Bug
#16914007)
• InnoDB: InnoDB would attempt to gather statistics on partially created indexes. (Bug #16907783)
• InnoDB: To avoid namespace clashes, usage of 'using namespace std' has been removed
from InnoDB. (Bug #16899560)
• InnoDB: When dropping all indexes on a column with multiple indexes, InnoDB failed to block a
DROP INDEX operation when a foreign key constraint requires an index. (Bug #16896810)
• InnoDB: Optimized explicit record locking routines. (Bug #16880127)
• InnoDB: The server would crash during a memcached set operation. The failure was due to a
padded length value for a utf8 CHAR column. During a memcached update operation, a field from
an old tuple would be copied with a data length that was less than the padded utf8 CHAR column
value. This fix ensures that old tuples are not copied. Instead, a new tuple is created each time. (Bug
#16875543)
• InnoDB: innochecksum would ignore the return value of fwrite which could result in an error or
generate warnings and compilation errors when WITH_INNODB_EXTRA_DEBUG CMake is enabled.
(Bug #16872677)
• InnoDB: An assertion failure would occur in file row0log.cc on ROW_FORMAT=REDUNDANT tables
that contained an unexpected but valid data directory flag. (Bug #16863098)
• InnoDB: An assertion in row0mysql.cc, which ensures that the dictionary operation lock is not
taken recursively, failed. (Bug #16862290)
• InnoDB: The two INFORMATION_SCHEMA tables for the InnoDB buffer pool could show an invalid
page type for read-fixed blocks. This fix will show the unknown page type for blocks that are I/O-fixed
for reading. (Bug #16859867)
• InnoDB: InnoDB record comparison functions have been simplified and optimized. (Bug
#16852278)
275
MySQL 5.7 Release Notes
• InnoDB: Removed invalid compilation warning messages that appeared when compiling the InnoDB
memcached plugin. (Bug #16816824)
• InnoDB: During an insert buffer merge, InnoDB would invoke
lock_rec_restore_from_page_infimum() on a potentially invalid record pointer. (Bug
#16806366)
• InnoDB: The innodb_rwlock_x_spin_waits item in the
INFORMATION_SCHEMA.INNODB_METRICS table would show the same value as the
innodb_rwlock_x_os_waits item. (Bug #16798175)
• InnoDB: The trx_tables_locked counter in INFORMATION_SCHEMA.INNODB_TRX would not
account for all tables with locks. (Bug #16793724)
• InnoDB: This patch removes the UNIV_INTERN function, which was introduced in MySQL 5.1
to help replace static linking in InnoDB with the shared object plugin. UNIV_INTERN is no longer
required. (Bug #16781511)
• InnoDB: In debug builds, an online ALTER TABLE operation that performed a full table copy
would raise an assertion. The assertion was due to a race condition that would occur during BLOB
retrieval, when applying the table modification log to any log block except for the very last one. This
fix modifies row_log_table_apply_convert_mrec() to ensure that an index B-tree lock is
acquired to protect the access to log->blobs and the BLOB page. (Bug #16774118)
• InnoDB: In debug builds, an assertion could occur in OPT_CHECK_ORDER_BY when using binary
directly in a search string, as binary may include NULL bytes and other non-meaningful characters.
This fix will remove non-meaningful characters before the search is run. (Bug #16766016)
• InnoDB: The page_zip_validate() debug function, which is enabled when UNIV_ZIP_DEBUG is
defined at compilation time, invokes page_zip_decompress(), which in turn would update some
compression statistics. This would cause some mysql-test-run tests to fail. (Bug #16759605)
• InnoDB: Valgrind testing returned memory leak errors which resulted from a regression introduced
by the fix for Bug #11753153. The dict_create_add_foreign_to_dictionary function would
call pars_info_create but failed to call pars_info_free. (Bug #16754901)
• InnoDB: When the function trx_rollback_or_clean_recovered() rolls back or cleans
up transactions during a crash recovery, it removes the trx objects from the trx_sys list
without freeing up the memory used by those objects. To prevent a memory leak, this fix adds
trx_free_for_background() calls to trx_rollback_resurrected(), the function that
removes the trx objects. (Bug #16754776)
• InnoDB: A memory leak would occur in dict_check_tablespaces_and_store_max_id()
when space_id is equal to zero. (Bug #16737332)
• InnoDB: The page_zip_validate() consistency check failed after compressing a page, in
page_zip_compress(). This problem was caused by page_zip_decompress(), which failed to
set heap_no correctly when a record contained no user data bytes. A record with no user data bytes
occurs when, for example, a primary key is an empty string and all secondary index fields are NULL
or an empty string. (Bug #16736929)
• InnoDB: A missing comma in SHOW STATUS output would break MySQL Enterprise Monitor parsing.
(Bug #16723686)
• InnoDB: This patch is a code cleanup which may provide a minor performance improvement when
keys are not used on columns and when using the default latin1_swedish_ci collation. (Bug
#16723431)
• InnoDB: Some characters in the identifier for a foreign key constraint are modified during table
exports. (Bug #16722314, Bug #69062)
276
MySQL 5.7 Release Notes
• InnoDB: After a clean shutdown, InnoDB does not check .ibd file headers at startup. As a result,
in a crash recovery scenario, InnoDB could load a corrupted tablespace file. This fix implements
consistency and status checks to avoid loading corrupted files. (Bug #16720368)
• InnoDB: A regression introduced with the fix for Bug #11762038 would cause InnoDB to raise
an incorrect error message. The message stated that, “InnoDB cannot delete/update rows with
cascading foreign key constraints that exceed max depth of 20”. The error message would occur
when killing connections reading from InnoDB tables that did not have foreign key constraints. (Bug
#16710923)
References: This issue is a regression of: Bug #11762038.
• InnoDB: Stale InnoDB memcached connections would result in a memory leak. (Bug #16707516,
Bug #68530)
• InnoDB: In debug builds, an assertion failure would occur if innodb_log_group_home_dir
does not exist. Instead of an assertion, InnoDB now aborts with an error message if
innodb_log_group_home_dir does not exist. (Bug #16691130, Bug #69000)
• InnoDB: An existing full-text index would become invalid after running ALTER TABLE ADD
FULLTEXT due to an unsynchronized full-text cache. (Bug #16662990, Bug #17373659)
• InnoDB: An INSERT into a temporary table resulted in the following assert: ASSERT ID > 0 IN
TRX_WRITE_TRX_ID(). This fix corrects conditions for moving a transaction from a read-only list to
a read-write list when the server is running in read-only mode. (Bug #16660575)
• InnoDB: Shutting down and restarting InnoDB with --innodb-force-recovery set
to 3 or greater (4, 5, or 6) and attempting to drop a table would result in a crash. With
innodb_force_recovery mode set to 3 or greater DML operations should be blocked and DDL
operations allowed. This fix ensures that DDL operations are allowed. (Bug #16631778)
• InnoDB: A race condition would occur between ALTER TABLE ... ADD KEY and INSERT
statements, resulting in an “Unable to Purge a Record” error. (Bug #16628233)
• InnoDB: Very large InnoDB full-text search (FTS) results could consume an excessive amount
of memory. This bug fix reduces memory consumption for FTS results and introduces a new
configuration parameter, innodb_ft_result_cache_limit, which places a default size limit of
2000000000 bytes on the InnoDB FTS query result cache. innodb_ft_result_cache_limit
has an unlimited maximum value and can be set dynamically. (Bug #16625973)
• InnoDB: This fix addresses a race condition that would occur between the rollback of a recovered
transaction and creation of a secondary index in a locked operation. The race condition would
corrupt the secondary index. (Bug #16593427)
• InnoDB: DML operations on compressed temporary tables would result in a Valgrind error in the
buffer manager stack. (Bug #16593331)
• InnoDB: When ADD PRIMARY KEY columns are reordered in an ALTER TABLE statement (for
example: ALTER TABLE t1 ADD PRIMARY KEY(a,b), CHANGE a a INT AFTER b), the log
apply for UPDATE operations failed to find rows. (Bug #16586355)
• InnoDB: A code regression resulted in a record lock wait in a dictionary operation. A code
modification made to avoid starting a transaction on a temporary table failed to reset the state back
to init upon completion of the operation. If a transaction is started, the state is usually reset by
trx_commit. To catch similar problems in the future, this fix adds asserts to innobase_commit(),
innobase_rollback(), and ha_innobase::update_thd() that trigger when trx>dict_operation and trx->dict_operation_lock_mode are not set. (Bug #16575799)
• InnoDB: In debug builds, the assert_trx_in_list() assert failed, causing a race condition. This
fix removes the assert. The same assert is verified in the caller and existing checks are sufficient.
(Bug #16567258)
277
MySQL 5.7 Release Notes
• InnoDB: The MySQL printf facility (my_vsnprintf) did not understand the Microsoft I32 and I64
integer format width specifiers, such as %I64u for printing a 64-bit unsigned integer. As a result,
DBUG_PRINT could not be used with the InnoDB UINT64PF format, which is defined as %I64u
on Windows. This fix replaces the non-standard “I64” and “I32” length modifiers on Windows with
“ll” and “l” so that they will be understood by both my_snprintf() and ut_snprintf(). (Bug
#16559119)
• InnoDB: ALTER TABLE operations on InnoDB tables that added a PRIMARY KEY using a column
prefix could produce an incorrect result. (Bug #16544336)
• InnoDB: For ALTER TABLE operations on InnoDB tables that required a table-copying operation,
other transactions on the table might fail during the copy. However, if such a transaction issued a
partial rollback, the rollback was treated as a full rollback. (Bug #16544143)
• InnoDB: The row0purge.h include file contained a self-referencing inclusion. (Bug #16521741)
• InnoDB: During a transaction commit, prepare_commit_mutex is acquired to preserve the
commit order. If the commit operation failed, the transaction would be rolled back but the mutex
would not be released. Subsequent insert operations would not be able to acquire the same mutex.
This fix frees prepare_commit_mutex during innobase_rollback. (Bug #16513588)
• InnoDB: The recv_writer thread would only start after all redo log scans finished. In the case
of multiple redo log scans, accumulated redo records would be applied after each scan and before
processing the next scan. The absence of the recv_writer thread to help with flushing would slow
recovery or result in a server startup timeout. This fix ensures that the recv_writer thread starts
before the first scan batch is processed. (Bug #16501172)
• InnoDB: Under certain circumstances, LRU flushing would take a long time possibly affecting all
flushing activity and causing a shutdown timeout. (Bug #16500209)
• InnoDB: The InnoDB memcached test.demo_test table failed to work when defined as a utf8
charset table. (Bug #16499038)
• InnoDB: In cases where threads are forced to do single page flushing, fsync() would be triggered
for all data files. This fix allows for synchronous single page flushing. (Bug #16477781)
• InnoDB: This fix removes most calls to OS_THREAD_SLEEP from InnoDB. (Bug #16472953, Bug
#68588)
• InnoDB: FLUSH TABLES ... FOR EXPORT slept too often while flushing pages from buffer pools.
(Bug #16471701)
• InnoDB: Concurrently inserting into a full-text table would cause some inserts to fail. Duplicate
values would be generated for full-text search document IDs when performing inserts into a hidden
full-text search document ID column. (Bug #16469399)
• InnoDB: An InnoDB memcached file descriptor leak would cause a serious error. (Bug #16466664)
• InnoDB: The page_zip_available function would count some fields twice. (Bug #16463505)
• InnoDB: This fix replaces the IB_ULONGLONG_MAX constant with LSN_MAX where the code refers
to log sequence numbers, or with TRX_ID_MAX where trx->no is initialized to an undefined value.
This change does not alter the value of the constant. (Bug #16458660)
• InnoDB: This fix corrects the text for InnoDB error 6025, which stated, “InnoDB: read can't be
opened in ./ib_logfile0 mode.”. The corrected message states, “InnoDB: ./ib_logfile0 can't be opened
in read mode.” The variable and mode in the message construct were transposed. (Bug #16434398)
• InnoDB: When changing the shared tablespace file name using innodb_data_file_path and
leaving the current log files in place, InnoDB would create a new tablespace file and overwrite the
log files resulting in a mismatch between the data dictionary and tables on disk. This bug fix ensures
that InnoDB does not create a new tablespace if there are inconsistent system tablespaces, undo
tablespaces, or redo log files. (Bug #16418661)
278
MySQL 5.7 Release Notes
• InnoDB: Creating a foreign key constraint using the ALTER TABLE INPLACE algorithm requires
foreign_key_checks to be set to 0 (SET foreign_key_checks = 0;). As a result, an
appropriate duplicate ID check would not be performed. (Bug #16413976)
• InnoDB: When the InnoDB shutdown mode (innodb_fast_shutdown) is set to 2 and the master
thread enters the flush loop, the thread would not be able to exit under some circumstances. This
could lead to a shutdown hang. (Bug #16411457)
• InnoDB: In debug builds, an insert failed with an invalid assertion:
sync_thread_levels_g(array, level - 1, TRUE). (Bug #16409715)
• InnoDB: Crash recovery failed with a !recv_no_log_write assertion when reading a page. (Bug
#16405422)
• InnoDB: An ALTER TABLE operation that performed a table copy failed because a temporary
tablespace with the same name already existed. This fix makes temporary tables and tablespace
names more unique by adding the current log sequence number (LSN) to the end of the previous
table or file name. For example, table name “test/#sql-ib21” becomes “test/#sqlib21-1701208,” where 1701208 is the current LSN. Both the LSN and the table ID are needed to
ensure that the name is unique because it is theoretically possible for multiple threads to have the
same LSN. Including the table ID allows the temporary name to be associated with the table. (Bug
#16403420)
• InnoDB: Multiple concurrent calls to dict_update_statistics() would result in unnecessary
server load. (Bug #16400412)
• InnoDB: On 64-bit Windows builds, INNODB_BUFFER_POOL_SIZE would not accept an allocation
of more than 32GB. This limitation was due to a bug that truncated the internal value for the InnoDB
buffer pool size to 32 bits on 64-bit Windows builds. (Bug #16391722, Bug #68470)
• InnoDB: Restarting InnoDB in read-only mode and running a workload would occasionally return a
global_segment < os_aio_n_segments assertion. (Bug #16362046)
• InnoDB: DROP DATABASE failed if the database contained an InnoDB table that had a data file in
an external data directory. The external data file had an “InnoDB Symbolic Link” file type (.isl) that
was not recognized by MySQL. This fix adds .isl as a known InnoDB file type. (Bug #16338667)
• InnoDB: RENAME TABLE would result in a hang due to a MySQL mutex acquisition deadlock. (Bug
#16305265)
• InnoDB: This fix removes dated and incomplete code that is protected by the UNIV_LOG_ARCHIVE
macro. (Bug #16296837)
• InnoDB: Under testing, a FLUSH TABLES operation resulted in a timeout due to a missing
acknowledgment that the purge thread had stopped. (Bug #16277387)
• InnoDB: For compressed tables, a page reorganize operation would always write
an MLOG_ZIP_PAGE_REORGANIZE record to the redo log, which is only correct if
innodb_log_compressed_pages=OFF. When innodb_log_compressed_pages=ON, the page
reorganize operation should log the compressed page image. (Bug #16267120)
• InnoDB: When tables are linked by foreign key constraints, loading one table would open other
linked tables recursively. When numerous tables are linked by foreign key constraints, this would
sometimes lead to a thread stack overflow causing the server to exit. Tables linked by foreign key
constraints are now loaded iteratively. Cascade operations, which were also performed in a recursive
manner, are now performed iteratively using an explicit stack. (Bug #16244691, Bug #65384)
• InnoDB: After disabling foreign key checks with SET foreign_key_checks=0 and performing a
DROP INDEX, the table was no longer accessible after restarting the server. This fix allows the table
with missing foreign key indexes to be accessed when SET foreign_key_checks=0. When the
table is accessible, the user must recreate the missing indexes to fulfill the foreign key constraints.
(Bug #16208542, Bug #68148)
279
MySQL 5.7 Release Notes
• InnoDB: When a transaction is in READ COMMITTED isolation level, gap locks are still taken in
the secondary index when a row is inserted. This occurs when the secondary index is scanned
for duplicates. The function row_ins_scan_sec_index_for_duplicate() always calls the
function row_ins_set_shared_rec_lock() with LOCK_ORDINARY irrespective of the transaction
isolation level. This fix modifies the row_ins_scan_sec_index_for_duplicate() function to
call row_ins_set_shared_rec_lock() with LOCK_ORDINARY or LOCK_REC_NOT_GAP, based
on the transaction isolation level. (Bug #16133801, Bug #68021)
• InnoDB: Persistent statistics would be disabled unnecessarily when running in read-only mode.
When running in read-only mode, fetching statistics from disk does not involve any modification of
on-disk data except for when ANALYZE TABLE is run. This fix enables persistent statistics for readonly mode. (Bug #16083211)
• InnoDB: Starting mysqld with --innodb_log_buffer_size=50GB failed to allocate memory
and returned NULL. For non-debug builds there was no check in place and a segmentation fault
occurred. This fix adds a log message stating that memory failed to be allocated, and adds an
assertion. (Bug #16069598, Bug #68025)
• InnoDB: When UNIV_DEBUG is enabled in debug builds, buf_validate() is often called which
sometimes results in false alarms in tests on semaphore wait timeout. This fix increases counter
values to reduce false alarms. (Bug #16068056)
• InnoDB: While printing a UTF-8 table name, InnoDB would truncate the table name, resulting in an
incomplete buffer and subsequent Valgrind error. This bug fix also addresses an incorrect debugging
error message. (Bug #16066351)
• InnoDB: The explain_filename function, which provides information about a partition by
parsing the file name, would return an error when attempting to parse a file name with no partition
information. (Bug #16051728)
• InnoDB: Stopping the server, removing a database table (d1.t1) .frm file from the data directory,
restarting the server, and dropping the database (d1), would cause an assertion. (Bug #16043216)
• InnoDB: While processing read-write workloads, InnoDB would scan more pages than are required
for flushing, unnecessarily consuming CPU resource. (Bug #16037180)
• InnoDB: TRUNCATE TABLE failed to handle the return value from btr_create when btr_create
is invoked by TRUNCATE TABLE for creation of a new index. (Bug #16026889)
• InnoDB: An overflow would occur for innodb_row_lock_time_max and
innodb_row_lock_current_waits. This fix modifies code logic in storage/innobase/srv/
srv0srv.c. (Bug #16005310)
• InnoDB: Attempting to create a table while in innodb_read_only mode resulted in the following
error: ERROR 1015 (HY000): Can't lock file (errno: 165 - Table is read only).
(Bug #15963619)
• InnoDB: An active FLUSH TABLES ... FOR EXPORT thread would cause a hang during
shutdown. The fix ensures that trx_is_interrupted() is checked during ibuf_merge. (Bug
#15953255)
• InnoDB: innochecksum would return an error when run on compressed tables. (Bug #14612872,
Bug #66779)
• InnoDB: A multi-row INSERT ... ON DUPLICATE KEY UPDATE insert failure, caused by a
duplicate key error, would result in duplicate auto-increment values. (Bug #14483484, Bug #66301)
• InnoDB: A mismatch between .ibd files and the InnoDB data dictionary could occur if TRUNCATE
TABLE is interrupted by a crash. The mismatch would be encountered after recovery. To avoid this
problem, truncate table information is written to a truncate log file that resides temporarily in the log
directory. The truncate log file has the following naming convention: ib_space_id_trunc.log. If
280
MySQL 5.7 Release Notes
the TRUNCATE operation is successful, the truncate log file is removed. If the TRUNCATE operation is
interrupted by a crash, information is read from the truncate log file during recovery, the log records
are applied, and the truncate log file is removed. (Bug #14174004, Bug #13997329, Bug #17227149,
Bug #17238361)
• InnoDB: The documentation incorrectly stated that START TRANSACTION WITH CONSISTENT
SNAPSHOT provides a consistent snapshot only if the current isolation level is REPEATABLE READ
or SERIALIZABLE. START TRANSACTION WITH CONSISTENT SNAPSHOT only works with
REPEATABLE READ. All other isolation levels are ignored. The documentation has been revised and
a warning is now generated whenever the WITH CONSISTENT SNAPSHOT clause is ignored. (Bug
#14017206, Bug #65146)
• InnoDB: The srv_master_thread background thread, which monitors server activity and
performs activities such as page flushing when the server is inactive or in a shutdown state, runs on
a one second delay loop. srv_master_thread failed to check if the server is in a shutdown state
before sleeping. (Bug #13417564, Bug #63276)
• InnoDB: In the error log, a full-text search index would be reported missing from the data dictionary
during a TRUNCATE TABLE operation. After restarting mysqld, the following InnoDB error would
be reported: “InnoDB: Error: trying to load index idx13 for table test/g1 but
the index tree has been freed..” (Bug #12429565)
References: See also: Bug #17402002.
• InnoDB: When the value provided for innodb_buffer_pool_size on 32-bit
systems is too large, an error message would incorrectly reference the internal variable,
innobase_buffer_pool_size, instead of innodb_buffer_pool_size. (Bug #11759578, Bug
#51901)
• InnoDB: Compiling InnoDB on Windows Vista 64-bit with Visual Studio 2005 would result in
compilation errors. (Bug #11752731, Bug #44004)
• InnoDB: The row_check_index_for_mysql method, which checks for NULL fields during an
index scan or CHECK TABLE operation, would iterate unnecessarily. Thanks to Po-Chun Chang for
the patch to correct this issue. (Bug #69377, Bug #16896647)
• InnoDB: When running an InnoDB full-text search in boolean mode, prefixing an asterisk (*) to a
search string ('*string') would result in an error whereas for MyISAM, a prefixed asterisk would
be ignored. To ensure compatibility between InnoDB and MyISAM, InnoDB now handles a prefixed
asterisk in the same way as MyISAM. (Bug #68948, Bug #16660607)
• InnoDB: Successive deletes in descending key order would lead to under-filled InnoDB index
pages. When an InnoDB index page is under-filled, it is merged with the left or right sibling node.
The check performed to determine if a sibling node is available for merging was not functioning
correctly. (Bug #68501, Bug #16417635)
• InnoDB: Setting foreign_key_checks=0 and running ALTER TABLE to change the character
set of foreign key columns for a database with multiple tables with foreign key constraints would
leave the database in an inconsistent state. Subsequent ALTER TABLE operations (using the COPY
algorithm) with foreign_key_checks=1 would fail due to the detected inconsistency. Reversion of
the partially executed ALTER TABLE operation would also fail, resulting in the loss of the table being
altered. When running the same ALTER TABLE operation with a RENAME clause, the inconsistency
would not be detected but if the ALTER TABLE operation failed for some other reason, reversion of
the partially executed ALTER TABLE failed with the same result.
The bug fix temporarily disables foreign_key_checks while the previous table definition is
restored. (Bug #65701, Bug #14227431)
• InnoDB: Creating a table with a comment or default textual value containing an apostrophe that is
escaped with a backslash would sometimes cause the InnoDB storage engine to omit foreign key
definitions. (Bug #61656, Bug #12762377)
281
MySQL 5.7 Release Notes
• InnoDB: The pthread_mutex, commit_threads_m, which was initialized but never used, has
been removed from the code base. (Bug #60225, Bug #11829813)
• InnoDB: In many cases InnoDB calls exit(1) when it encounters a fatal error. An exit(1) call
does not produce a crash dump or provide information about the process state. Additionally, on
Windows, an exit(1) call does not report a crashed process in the Event Viewer. This fix replaces
exit(1) calls with ut_error calls in a number of places. (Bug #56400, Bug #11763660)
• Partitioning: Creating a table t1 using CREATE TABLE ... PARTITION BY LIST ...
PARTITION ... VALUES IN (NULL), then attempting to execute CREATE TABLE ... LIKE
t1 caused the server to fail. (Bug #16860588)
• Partitioning: When upgrading to MySQL 5.5.31 or higher, a message is written into the output of
mysql_upgrade when encountering a partitioned table for which the ALGORITHM option is required
to maintain binary compatibility with the original; the message includes the ALTER TABLE statement
required to make the change. For such a table having a sufficiently large number of partitions, the
message was truncated with an error before the complete ALTER TABLE statement could be written.
(Bug #16589511)
• Partitioning: When a range was specified in the WHERE condition of a query against a table
partitioned by range, and the specified range was entirely within one of the partitions, the next
partition was also checked for rows although it should have been pruned away.
Suppose we have a range-partitioned table t created using the following SQL statement:
CREATE TABLE t (
id INT AUTO_INCREMENT,
dt DATETIME,
PRIMARY KEY (dt,id),
UNIQUE KEY (id,dt)
)
PARTITION BY RANGE COLUMNS(dt) (
PARTITION p0 VALUES LESS THAN ('2013-01-01'),
PARTITION p1 VALUES LESS THAN ('2013-01-15'),
PARTITION p2 VALUES LESS THAN ('2013-02-01'),
PARTITION p3 VALUES LESS THAN ('2013-02-15'),
PARTITION pmax VALUES LESS THAN (MAXVALUE)
);
An example of a query that exhibited this issue when run against t is shown here:
SELECT COUNT(*) FROM t
WHERE dt >= '2013-02-01' AND dt < '2013-02-15';
In this case, partition pmax was checked, even though the range given in the WHERE clause lay
entirely within partition p3. (Bug #16447483)
• Partitioning: When dropping a partitioned table, the table's .par file was deleted first, before the
table definition or data. This meant that, if the server failed during the drop operation, the table could
be left in an inconsistent state in which it could neither be accessed nor dropped.
The fix for this problem makes the following changes:
• Now, when dropping a partitioned table, the table's .par file is not removed until all table data has
been deleted.
• When executing DROP TABLE of a partitioned table, in the event that its .par file is determined to
be missing, the table's .frm file is now immediately deleted, in effect forcing the drop to complete.
(Bug #13548704, Bug #63884)
• Replication; Microsoft Windows: On Windows platforms, issuing SHOW SLAVE STATUS while the
slave I/O thread was being terminated due to an error caused the slave to fail. (Bug #16662771)
282
MySQL 5.7 Release Notes
• Replication: The server attempted to perform an internal truncatation of the slave_worker_info
table while resetting it, even though this is a DDL operation and should not be used conccurrently
with DML operations. To prevent this from happening, the reset now performs sequential row
deletion in place of the truncation operation. (Bug #17286858, Bug #69898)
• Replication: The data size for a table map event created during execution was calculated, but not
when the event was created from a network packet. This could later cause problems when the data
fields of such events were treated as if they had a length equal to 0 when trying to write the events to
a cache, or to the binary log.
To avoid future problems of this nature, the table map's data size is now calculated in both cases.
(Bug #17164074)
• Replication: When the --relay-log-info-file option was used together with --slaveparallel-workers set to a value greater than 1, mysqld failed to start. (Bug #17160671)
• Replication: The commit error caused by the failure of binary log rotation failure generated an
incident event in the binary log file and interrupted the user session with error messages which did
not mention that the slave server would be stopped later when the incident event was replayed.
Now, when encountering binary log rotation failure, a more helpful error message is instead written to
the log, alerting the user to investigate in a timely manner. (Bug #17016017)
• Replication: The condition leading to the issue fixed in Bug #16579083 continued to raise an error
even though the condition itself no longer cause the issue to occur. (Bug #16931177, Bug #69369)
References: See also: Bug #16271657, Bug #16491597, Bug #68251, Bug #68569. This issue is a
regression of: Bug #16579083.
• Replication: The mysqlbinlog option --rewrite-db caused USE statements to be ignored, even
for databases that were not referenced by the option. (Bug #16914535)
• Replication: When rpl_semi_sync_master_timeout was set to an extremely large value,
semisynchronous replication became very slow, especially when many sessions were working in
parallel. It was discovered that the code to calculate this timeout was inside the wait loop itself, with
the result that an increase in the value of rpl_semi_sync_master_timeout caused repeated
iterations. This fix improves the method used to calculate wakeup times, and moves it outside of the
wait loop, so that it is executed one time only. (Bug #16878043, Bug #69341)
• Replication: It was possible to cause a deadlock after issuing FLUSH TABLES WITH READ LOCK
by issuing STOP SLAVE in a new connection to the slave, then issuing SHOW SLAVE STATUS using
the original connection.
The fix for this includes the addition of the rpl_stop_slave_timeout system variable, to control
the time in seconds to wait for slave to stop after issuing STOP SLAVE before returning a warning.
(Bug #16856735)
• Replication: It was possible in CHANGE MASTER TO statements to set the MASTER_DELAY option
greater than the supported maximum value (231 − 1). In addition, the error resulting from setting
MASTER_DELAY to a value greater than 232 was not handled correctly. (Bug #16820156, Bug
#16960315, Bug #69249, Bug #69469)
• Replication: Some expressions employing variables were not handled correctly by LOAD DATA.
(Bug #16753869)
• Replication: In some circumstances, the message in the Last_Error column from the output
of SHOW SLAVE STATUS referred to GTID_NEXT_LIST although this variable is not currently
implemented (the name is reserved for possible future use). Now in such cases the error message
no longer refers to this variable. (Bug #16742886, Bug #69096)
References: See also: Bug #16715809, Bug #69045.
283
MySQL 5.7 Release Notes
• Replication: mysqlbinlog --rewrite-db failed when the name of the destination database
contained any underscore (_) characters. (Bug #16737279)
• Replication: Issuing a FLUSH TABLES statement on a GTID-enabled master caused replication
to fail. It was found that this misbehavior was introduced by the fix for Bug #16062608, which
disallowed statements that perform an implicit commit but whose changes are not logged when
gtid_next is set to any value other than AUTOMATIC. The changes made in that fix have been
reverted, and such statements are (again) allowed without regard to the value of this variable. (Bug
#16715809, Bug #69045)
References: Reverted patches: Bug #16062608.
• Replication: Point-in-time recovery could fail when trying to restore a single database from a binary
log in row-based format using mysqlbinlog with the --database option. (Bug #16698172)
• Replication: A crash-on-commit error caused InnoDB to lose the previous transaction following
execution of a RESET MASTER statement. This occurred because the prepare phase caused a flush
to disk, while the commit phase did not perform a corresponding flush within InnoDB.
To fix this problem, RESET MASTER now causes storage engine logs to be flushed on commit. (Bug
#16666456, Bug #68932)
• Replication: When processing an Update_rows_log_event or Delete_rows_log_event from
the binary log, the before image is hashed and stored in a hash table. Following this, the original
table is scanned for the desired records; subsequent processing hashes each record fetched from
the original table and performs a lookup for it in the hash table. However, columns read from the
image that had originally been set to NULL could instead contain random or “garbage” data, causing
the lookup (and thus replication) to fail with an error such as Could not execute Update_rows
event on table.... (Bug #16621923)
References: See also: Bug #11766865. This issue is a regression of: Bug #16566658.
• Replication: When used with the options --dump-slave --include-master-host-port,
mysqldump printed the port number within quotation marks, as if it were a string value rather than an
integer. (Bug #16615117)
• Replication: Linker errors occurred if the header file log_event.h was included in an application
containing multiple source files, because the file rpl_tblmap.cc was included in log_event.h.
This fix moves the inclusion of rpl_tblmap.cc into the source files that use log_event.h. (Bug
#16607258)
• Replication: The error displayed by SHOW SLAVE STATUS when a worker thread fails to apply
an event contained no event coordinate information. The GTID for the event's group was also not
shown. Now in such cases, the text shown for Last_SQL_Error is prefixed with the (physical)
master binary log coordinates, as well as the value of gtid_next when this has been set. (Bug
#16594095)
• Replication: A session attachment error during group commit causes the rollback of the transaction
(as intended), but the transaction in which this happened was still written to the binary log and
replicated to the slave. Thus, such an error could lead to a mismatched master and slave.
Now when this error occurs, an incident event is written in the binary log which causes replication
to stop, and notifies the user that redundant events may exist in the binary log. An additional error
is also now reported to the client, indicating that the ongoing transaction has been rolled back. (Bug
#16579083)
• Replication: Due to time resolution issues on some systems, the time to be taken by the dump
thread for a reply from the slave could be calculated to be less than zero, leading to Semi-sync
master wait for reply fail to get wait time errors. Since this condition does not have
a negative impact on replication, errors caused by these conditions have been reduced to warnings.
(Bug #16579028)
284
MySQL 5.7 Release Notes
• Replication: Running the server with --log-slave-updates together with --replicate-wildignore-table or --replicate-ignore-table in some cases caused updates to user variables
not to be logged. (Bug #16541422)
• Replication: When using mysqlbinlog and the mysql client to roll forward two or more binary logs
on a server having GTIDs enabled, the gtid_next variable was not properly reset when switching
from the first to the second binary log, causing processing to halt with an error at that point. (Bug
#16532543)
• Replication: The mysqlbinlog options --include-gtids, --exclude-gtids, and --skipgtids did not work correctly when trying to process multiple files. (Bug #16517775)
• Replication: When one or more GTID log events but no previous GTIDs log events were found
in the binary log, the resulting error was mishandled and led to a failure of the server. (This is an
extremely rare condition that should never occur under normal circumstances, and likely indicates
that the binary log file has somehow been corrupted.) Now in such cases, an appropriate error is
issued, and is handled correctly. (Bug #16502579, Bug #68638)
• Replication: Attempting to execute START SLAVE after importing new slave_master_info and
slave_relay_log_info tables failed with an empty error message. Now an appropriate error and
message are issued in such cases. (Bug #16475866, Bug #68605)
• Replication: Restarting the server after the slave_relay_log_info table had been emptied
caused mysqld to fail while trying to return an error. (Bug #16460978, Bug #68604)
• Replication: The warning issued when specifying MASTER_USER or MASTER_PASSWORD with
CHANGE MASTER TO was unclear for a number of reasons, and has been changed to read,
Storing MySQL user name or password information in the master info
repository is not secure and is therefore not recommended. Please consider
using the USER and PASSWORD connection options for START SLAVE; see 'START
SLAVE Syntax' in the MySQL Manual for more information. (Bug #16460123, Bug
#16461303, Bug #68602, Bug #68599)
• Replication: Extra binary log rotations were performed due to concurrent attempts at rotation when
the binary log became full, which were allowed to succeed. This could lead to the unnecessary
creation of many small binary log files. (Bug #16443676, Bug #68575)
• Replication: When the size of an execution event exceeded the maximum set for the buffer
(slave_pending_jobs_size_max), row-based replication could hang with Waiting for slave
workers to free pending events. (Bug #16439245, Bug #68462)
• Replication: Following disconnection from the master, the slave could under certain conditions
report erroneously on reconnection that it had received a packet that was larger than
slave_max_allowed_packet, causing replication to fail. (Bug #16438800, Bug #68490)
• Replication: A slave using row-based replication was unable to read the rows containing columns of
type MYSQL_TYPE_DECIMAL properly (old-style decimal, used prior to MySQL 5.0.3). Now the slave
throws an error if it receives this type of data. You can convert the old-style DECIMAL format to the
binary format used in current MySQL releases with ALTER TABLE; see Upgrading from MySQL 4.1
to 5.0, for more information. (Bug #16416302)
• Replication: An SQL thread error during MTS slave recovery caused the slave to fail. (Bug
#16407467, Bug #68506)
• Replication: When using the options --read-from-remote-server --stop-never -base64-output=decode-rows --verbose, mysqlbinlog failed to reset the counter used
to store the current position within the file when the binary log on the server was rotated. (Bug
#16316123, Bug #68347)
• Replication: When using mysqldump to back up a database created with MySQL 5.6.4 or
an earlier version, setting --set-gtid-purged=AUTO caused the backup to fail, because
pre-5.6.5 versions of MySQL did not support GTIDs, and it could not be determined if GTIDs
285
MySQL 5.7 Release Notes
were enabled for the database. This fix makes sure mysqldump does not attempt to output a SET
@@global.gtid_purged statement when backing up any pre-5.6.5 databases. (Bug #16303363,
Bug #68314)
• Replication: DROP TEMP TABLE IF EXISTS statements could lead to failures in applying the
binary log during point-in-time recovery operations. This is due to the fact that, when using rowbased replication, the server appends IF EXISTS to any DROP TEMPORARY TABLE statements
written to the binary log, and that the slave SQL thread does not check * wildcard filter rules for DROP
TEMPORARY TABLE IF EXISTS. If --log-slave-updates was also enabled on the slave, such
a statement was preceded by a USE statement. If the database referred by the USE statement did not
exist, the statement failed, and stopped replication.
Now, when writing DROP TEMPORARY TABLE IF EXISTS into the binary log, no USE statement
is written, and the table name in the DROP TEMPORARY TABLE statement is a fully qualified table
name. (Bug #16290902)
• Replication: Deadlocks could sometimes occur on group commits with a high number of concurrent
updates, as well as when one client held a lock from a commit while another client imposed a lock
while rotating the binary log. (Bug #16271657, Bug #16491597, Bug #68251, Bug #68569)
• Replication: After a transaction was skipped due to its GTID already having been logged, all
remaining executed transactions were incorrectly skipped until gtid_next was pointed to a different
GTID.
To avoid this incorrect behavior, all transactions—even those that have been skipped—are marked
as undefined when they are commited or rolled back, so that an error is thrown whenever a
second transaction is executed following the same SET @@session.gtid_next statement. (Bug
#16223835)
• Replication: When semisynchronous replication was enabled, the automatic dropping on the
master of an event created using ON COMPLETION NOT PRESERVE caused the master to fail. (Bug
#15948818, Bug #67276)
• Replication: Modifying large amounts of data within a transaction can cause the creation of
temporary files. Such files are created when the size of the data modified exceeds the size of the
binary log cache (max_binlog_cache_size). Previously, such files persisted until the client
connection was closed, which could allow them to grow until they exhausted all available disk space
in tmpdir. To prevent this from occurring, the size of a temporary file created in this way in a given
transaction is now reset to 0 when the transaction is committed or rolled back. (Bug #15909788, Bug
#18021493, Bug #66237)
• Replication: When the master had more than one table with an auto-increment column, and the
slave ignored at least one of these tables due to --replicate-ignore-table rules, but at least
one them was replicated, even so—the replicated table or tables having at least one trigger updating
one or more tables existing only on the slave—updates to any of the auto-increment tables on the
master caused replication to fail. (Bug #15850951, Bug #67504)
• Replication: Setting a SET column to NULL inside a stored procedure caused replication to fail. (Bug
#14593883, Bug #66637)
• Replication: The binary log contents got corrupted sometimes, because the function
MYSQL_BIN_LOG::write_cache always thought it had reached the end-of-cache when the
function my_b_fill() reported a '0,' while that could also mean an error had occurred. This fix
makes sure that whenever my_b_fill() returns a '0,' an error check is performed on info>error. (Bug #14324766, Bug #60173)
• Replication: The internal function MYSQL_BIN_LOG::open_binlog() contained an unneeded
variable, which has been removed. (Bug #14134590, Bug #60188)
• Replication: PURGE BINARY LOGS by design does not remove binary log files that are in use or
active, but did not provide any notice when this occurred. Now, when log files are not removed under
286
MySQL 5.7 Release Notes
such conditions, a warning is issued; this warning includes information about the file or files were not
removed when the statement was issued. (Bug #13727933, Bug #63138)
• Replication: It was possible for the multi-threaded slave coordinator to leak memory when the
slave was stopped while waiting for the next successful job to be added to the worker queue. (Bug
#13635612)
• Replication: When replicating to a BLACKHOLE table using the binary logging format, updates and
deletes cannot be applied and so are skipped. Now a warning is generated for this whenever it
occurs.
Note
binlog_format=STATEMENT is recommended when replicating to tables
that use the BLACKHOLE storage engine.
(Bug #13004581)
• Replication: Temporary files created by LOAD DATA INFILE were not removed if the statement
failed. (Bug #11763934, Bug #56708)
• Replication: After the client thread on a slave performed a FLUSH TABLES WITH READ LOCK
and was followed by some updates on the master, the slave hung when executing SHOW SLAVE
STATUS. (Bug #68460, Bug #16387720)
• Microsoft Windows: On Microsoft Windows, passing in --local-service to mysqld.exe when
also passing in a service name could cause a crash at startup. (Bug #16999777, Bug #69549)
• The execution time of a query involving a stored function was affected by the number of warnings
generated by the previous statement in the same session. (Bug #23031008, Bug #80922)
• The contents of SQL condition items such as TABLE_NAME, CONSTRAINT_NAME, an so forth were
lost if resignaled by a stored routine condition handler. (Bug #17280703)
• AES_ENCRYPT() and AES_DECRYPT() failed to work correctly when MySQL was built with an
AES_KEY_LENGTH value of 192 or 256. (Bug #17170207)
• SELECT * from performance_schema.events_statements_current could raise an
assertion due to a race condition under load. (Bug #17164720)
• InnoDB full-text searches failed in databases whose names began with a digit. (Bug #17161372)
• A successful connection failed to reset the per-IP address counter used to count
successive connection failures. This could possibly cause a host to be blocked, when the
max_connect_errors limit was reached. (Bug #17156507)
• With the thread pool plugin enabled and SSL in use, an error in one connection might affect other
connections, causing them to experience a lost connection. (Bug #17087862)
• Under load, truncating the accounts Performance Schema table could cause a server exit. (Bug
#17084615)
• my_pthread.h unconditionally included pfs_thread_provider.h, a noninstalled header file,
resulting in compilation failure when compiling MySQL applications against the installed header files.
(Bug #17061480)
• Indexed lookups on POINT columns was slower for InnoDB tables in MySQL 5.7 compared to 5.6.
(Bug #17057168)
• The Performance Schema was built for embedded server builds. This no longer occurs. (Bug
#17041705)
• Reads from message buffers for closed connections could occur. (Bug #17003702)
287
MySQL 5.7 Release Notes
• The server could exit while using a cursor to fetch rows from a UNION query. (Bug #16983143)
• The range optimizer incorrectly assumed that any geometry function on a spatial index returned rows
in ROWID order, which could result in incorrect query results. (Bug #16960800)
• mysql_secure_installation did not properly clean up the mysql.proxies_privs table for
removed accounts. (Bug #16959850)
• A race condition in the thread pool plugin could cause status variables such as Aborted_connects
not to be incremented and permitting concurrent kills to happen for the same thread ID. (Bug
#16959022)
• At server startup, it was possible to set the validate_password_length system variable to a
value smaller than permitted by the values of other password-length variables related to it. (Bug
#16957721)
• Initialization of keycache_* variables (see Multiple Key Caches) during server startup could write to
incorrect memory. (Bug #16945503)
• For debug builds, improper use of SAFE_MUTEX within dbug.c caused different code areas to have
different ideas about size and contents of a mutex. This could result in out-of-bounds memory writes.
(Bug #16945343)
• The Performance Schema could spawn a thread using incorrect instrumentation information. (Bug
#16939689)
• The server did excessive locking on the LOCK_active_mi and active_mi->rli->data_lock
mutexes for any SHOW STATUS LIKE 'pattern' statement, even when the pattern did not match
status variables that use those mutexes (Slave_heartbeat_period, Slave_last_heartbeat,
Slave_received_heartbeats, Slave_retried_transactions, Slave_running). Now
attempts to show those variables do not lock those mutexes. This might result is slightly stale data,
but better performance. (Bug #16904035)
• Full-text phrase search in InnoDB tables could read incorrect memory. (Bug #16885178)
• It was not possible to keep several major versions of MySQL in the same yum repository. (Bug
#16878042)
• Excessive memory consumption was observed for multiple execution of a stored procedure under
these circumstances: 1) The stored procedure had an SQL statement that failed during validation. 2)
The stored procedure had an SQL statement that required repreparation. (Bug #16857395)
• The Batched Key Access method could return incorrect results on big-endian machines if a table
buffered in the BKA join cache used a storage engine such as InnoDB or MyISAM with little-endian
storage format, and then the next table used a storage engine such as NDB with native-endian
storage format. (Bug #16853897)
• The error string for ER_COL_COUNT_DOESNT_MATCH_PLEASE_UPDATE string contained a
hardcoded database name ('mysql.%s'), which is incorrect when the error referred to a table in a
different database. (Bug #16813605)
• An assertion could be raised when the optimizer considered pushing down an index condition
containing an updatable user variable and did not contain fields from the index. (Bug #16804581)
• If a SET statement containing a subquery caused a deadlock inside InnoDB, InnoDB rolled back the
transaction. However, the SQL layer did not notice this and continued execution, resulting eventually
in an assertion being raised inside InnoDB. (Bug #16802288)
• Removing a server RPM package did not shut down the existing server if it was running. (Bug
#16798868)
• Some errors in MySQL 5.7 had different numbers than in MySQL 5.6. (Bug #16780120)
288
MySQL 5.7 Release Notes
• A race condition in the server could cause issues with the mysqld process ID file when startup
was aborted. As part of the fix for this issue, mysqld_safe now creates its own PID file
mysqld_safe.pid in the server's data directory. (Bug #16776528, Bug #70308)
• HAVE_REPLICATION now is set from CMake rather than in my_global.h so that it is not dependent
on my_global.h having been included. (Bug #16768511)
• INSERT ... ON DUPLICATE KEY UPDATE could cause a server exit if a column with no default
value was set to DEFAULT. (Bug #16756402)
References: This issue is a regression of: Bug #14789787.
• CMake now assumes the existence of standard C header files such as stdlib.h and stdarg.h.
(Bug #16748528)
• In a prepared statement or stored routine, if the HAVING clause of a subquery referenced some
column of the GROUP BY of the parent query, the server could exit. (Bug #16739050)
• Compiling failed with -DMY_ATOMIC_MODE_RWLOCKS=1 or on platforms on which MySQL did not
support lockless atomic operations (such as ARM). (Bug #16736461)
• Password rewriting in the general query log now also applies to prepared statements. (Bug
#16732621)
• The code base was modified to account for new warning checks introduced by gcc 4.8. (Bug
#16729109)
• The function fill_locks_row(), which is responsible for providing data for the
INFORMATION_SCHEMA.INNODB_LOCKS table, would try to look up the B-tree page in the
buffer pool for INFIMUM and SUPREMUM records, both of which have a predefined heap_no.
This generated unnecessary buffer pool contention and caused information to be omitted
when a page was not available in the buffer pool. This fix removes the buffer pool lookup for
PAGE_HEAP_NO_INFIMUM (heap_no=0) and PAGE_HEAP_NO_SUPREMUM (heap_no=1) from
fill_locks_row(). (Bug #16684523)
• The deprecated thread_concurrency system variable has been removed. (Bug #16661195)
• The read-only open_files_limit system variable did not show the maximum number of open
files the mysqld process could have, but instead the number that was requested after adjusting the
--open-files-limit command-line option. (Bug #16657588)
• Kill handling in the thread pool plugin was subject to timeout problems and Valgrind warnings. (Bug
#16633880)
• Overhead for setting PROCESSLIST_STATE values in the THREADS Performance Schema table has
been reduced. (Bug #16633515)
• Within a stored procedure, repeated execution of a prepared CREATE TABLE statement for a table
with partitions could cause a server exit. (Bug #16614004)
• The server could make the wrong decision about whether an account password was expired. (Bug
#16604641)
• The Windows authentication plugin failed to free a context buffer for each connection. (Bug
#16591288)
• Some rows for a session could be missing sporadically from the session_connect_attrs
Performance Schema table while the session was executing a workload. (Bug #16576980)
• The DBUG_PRINT() macro unnecessarily evaluated arguments when debugging was not enabled.
(Bug #16556597)
• Some problems compiling on Solaris in 64-bit mode with gcc and g++ were corrected. (Bug
#16555106)
289
MySQL 5.7 Release Notes
• SHOW WARNINGS and SHOW ERRORS did not properly reset the warning count. (Bug #16522662)
• Clients could determine based on connection error message content whether an account existed.
(Bug #16513435, Bug #17357528, Bug #19273967)
• Geometry methods that worked with WKB data performed insufficient input data validation, which
could cause Valgrind errors or a server exit. (Bug #16510712, Bug #12772601)
• The server could attempt a filesort operation for a zero-size sort length, causing it to exit. (Bug
#16503160)
• Opening a cursor on a SELECT within a stored procedure could cause a segmentation fault. (Bug
#16499751)
References: This issue is a regression of: Bug #14740889.
• CREATE TABLE or ALTER TABLE can fail if the statement specified unsupported options or
something was missing. Previously, such errors were returned as ER_ILLEGAL_HA. Now they are
returned as the new ER_MISSING_HA_CREATE_OPTION error. (Bug #16498740)
• Enabling the query cache could cause repeatable-read transactions to return incorrect results. (Bug
#16497925)
• my_load_defaults() was modified to accommodate some problems under compilation with gcc
4.7.2 that could cause a client crash during option processing. (Bug #16497125)
• Missing variable initialization led to incorrectly returning an error from
st_select_lex_unit::explain and led to a failed assertion. (Bug #16484966)
• When index condition pushdown was used on a descending range scan and the first range interval
did not contain any qualifying records, the result of the range scan could be empty even if other
range intervals contained qualifying records. (Bug #16483273)
• The WKB reader for spatial operations could fail and cause a server exit. (Bug #16451878)
• The ER_OUTOFMEMORY error was used in some places without the proper parameter being passed,
resulting in incorrect diagnostic output. (Bug #16449659)
• Failure to handle a full-text search wildcard properly could cause the server to exit. (Bug #16446108)
• Optimizer heuristics inappropriately preferred range access over ref access in cases when the ref
access referred to a column of a table earlier in the join seqence. (Bug #16437940)
• For queries using ref access on CHAR and VARCHAR data types, the ref access condition could be
evaluated again as part of the query condition or pushed down as an index condition to the storage
engine. (Bug #16437630)
• If the optimizer was using a loose index scan, the server could exit while attempting to create a
temporary table. (Bug #16436567)
• Incorrect results or a server exit could be caused by a reference to an aggregated expression inside
a nested subquery, where the aggregated expression was evaluated in a query block more than two
levels outer to the reference. (Bug #16436383)
• If a table has been marked as containing only NULL values for all columns if it is a NULLcomplemented row of an outer join, then rollup on the column which cannot be nullable results in a
server exit. (Bug #16436014)
• Unlike MyISAM, InnoDB does not support boolean full-text searches on nonindexed columns, but
this restriction was not enforced, resulting in queries that returned incorrect results. (Bug #16434374)
• Performance Schema parameter autosizing at startup did not take into account later autosizing
changes to other startup parameters on which the Performance Schema parameters depended. (Bug
#16430532)
290
MySQL 5.7 Release Notes
• A full-text search syntax error failed to print to standard output. (Bug #16429688, Bug #16765397)
• Some INFORMATION_SCHEMA queries that used ORDER BY did not use a filesort optimization
as they did in MySQL 5.5. (Bug #16423536)
• Debugging flags used to set the debug system variable were ignored if they were a prefix of
keywords already in the debugging list. (Bug #16415978)
• Manually-created accounts (using INSERT) with a malformed password effectively had no password.
(Bug #16414396)
• For debug builds, DBUG_EXPLAIN resulted in a buffer overflow when the debug system variable
value was more than 255 characters. (Bug #16402143)
• Several scripts in the sql-bench directory that were supposed to be executable did not have the
executable access bit set. (Bug #16395606)
• For debug builds, with an XA transaction in IDLE or PREPARED status, execution of a query with the
query cache enabled could cause a server exit. (Bug #16388996)
• If the primary key for the mysql.proc system table was removed (an unsupported and notrecommended operation), the server exited for subsequent stored procedure invocation. Similar
problems could occur for other system tables. Now an error occurs instead. (Bug #16373054)
• A server exit could occur for queries of the form SELECT (SELECT 1 FROM t1) IN (SELECT
a FROM t1) when attempting to evaluate the constant left-hand argument to the IN subquery
predicate. (Bug #16369522)
• An assertion could be raised when creating a index on a prefix of a TINYBLOB or GEOMETRY column
in an InnoDB column. (Bug #16368875, Bug #18776592, Bug #17665767)
• If a lock timeout resulted from an UPDATE with a nested SELECT being unable to access rows being
accessed by another thread, the error could go unchecked and cause an assertion to be raised later.
(Bug #16367039)
• In debug builds, failure in the range optimizer for an ER_LOCK_DEADLOCK or
ER_LOCK_WAIT_TIMEOUT error could go undetected and cause an assertion to be raised when a
response was sent to the client. In release builds, this problem manifested as clients receiving an OK
for a statement that had failed. (Bug #16366994, Bug #16247110)
• In debug builds, failure in the range optimizer for an ER_LOCK_DEADLOCK or
ER_LOCK_WAIT_TIMEOUT error could go undetected and cause the filesort code to raise an
assertion. In release builds, this problem manifested as clients receiving an ER_FILSORT_ABORT
rather than the correct error code. (Bug #16366881)
• For debug builds, set_field_to_null() could raise an assertion for attempts to insert NULL into
a NOT NULL column. (Bug #16362246)
• An assertion could be raised if, in greedy search mode, the optimizer identified join orders but was
unable to choose one. (Bug #16361170)
• A race condition in vio_shutdown() could cause a server exit. (Bug #16354789)
• For debug builds, GROUP_CONCAT(... ORDER BY) within an ORDER BY clause could cause a
server exit. (Bug #16347426)
• A GROUP_CONCAT() invocation containing subquery having an outer reference caused the server to
exit. (Bug #16347343)
• The validate_password plugin did not always enforce appropriate constraints against assigning
empty passwords. (Bug #16346443)
• Transforming some subqueries that select temporal or BIGINT types or to a semijoin caused a
server exit on the second execution of prepared statements or stored programs. (Bug #16319671)
291
MySQL 5.7 Release Notes
• Re-execution of a stored procedure could cause a server exit in
Item_field::fix_outer_field. (Bug #16317443)
• For debug builds, the server could exit for queries involving a nested subquery, a subquery
transformed into a semi-join and using a view. (Bug #16317076)
• The server could exit in do_copy_not_null() due to an improper NULL-value check. (Bug
#16316564)
• No warning was generated if a duplicate index existed after dropping a column associated with a
multiple-column index. (Bug #16315351)
• SELECT DISTINCT with WITH ROLLUP could result in a Duplicate entry 'NULL' for key
'<auto_key>' error. (Bug #16314835)
• Oracle RPM packages were unusable by yum due to issues with the obsoletes line in the .spec
file causing yum to interpret the package as obsoleting itself. (Bug #16298542)
• The range optimizer could set up incorrect ranges for queries that used XOR operations. (Bug
#16272562)
• mysql_secure_installation could not connect to the server if the account used had an
expired password. It invoked mysql noninteractively, resulting in that program failing to connect.
Now mysql supports a --connect-expired-password option that indicates to the server that
it can handle sandbox mode for expired-password accounts even if invoked noninteractively, and
mysql_secure_installation invokes mysql with this option. (Bug #16248315)
• The usual failed-login attempt accounting was not applied to failed COM_CHANGE_USER commands.
(Bug #16241992, Bug #17357535)
• For debug builds, an assertion could be raised if a failed LOAD DATA INFILE statement will
followed by an INSERT for the same table within the same session. (Bug #16240526)
• If loose index scan was used on a query that used MIN(), a segmentation fault could occur. (Bug
#16222245)
• For debug builds, an assertion was incorrectly raised for queries executed using eq_ref access and
filesort. (Bug #16164885)
• A user variable referenced during execution of a prepared statement is set to memory that is freed
at the end of execution. A second execution of the statement could result in Valgrind warnings when
accessing this memory. (Bug #16119355)
• Misoptimization of left expressions in prepared statements could cause a server exit. (Bug
#16095534)
• If my_write() encountered a disk-full condition, it could return an incorrect error value. (Bug
#16078792, Bug #19984788)
• The server could exit the second time a stored routine was invoked that performed an UPDATE or
DELETE using an invalid column in the join clause. (Bug #16078466)
• Certain queries containing ORDER BY or SQL_CALC_FOUND_ROWS could cause a server exit for
JSON-format EXPLAIN statements. (Bug #16077396, Bug #16078113)
• A prepared statement that used GROUP_CONCAT() and an ORDER BY clause that named multiple
columns could cause the server to exit. (Bug #16075310)
• ORDER BY MATCH ... AGAINST could cause a server exit. (Bug #16073689)
• Creating a FEDERATED table without specifying a connection string caused a server exit. (Bug
#16048546)
292
MySQL 5.7 Release Notes
• When a partition is missing, code in ha_innodb.cc would retry 10 times and sleep for a
microsecond each time while holding LOCK_open. The retry logic for partitioned tables was
introduced as a fix for Bug#33349 but did not include a test case to validate it. This fix removes the
retry logic for partitioned tables. If the problem reported in Bug#33349 reappears, a different solution
will be explored. (Bug #15973904)
• Client programs from MySQL 5.6.4 and up could confuse older servers during the connection
process by using newer protocol features not understood by older servers. (Bug #15965409)
• The mysql.server script exited with an error if the status command was executed with multiple
servers running. (Bug #15852074)
• In some cases, REVOKE could fail to revoke the GRANT OPTION privilege. (Bug #14799187)
• Use of the VALUES() function in the VALUES() clause of an INSERT statement could result in
Valgrind warnings or an unstable server, possibly leading to a server exit. (Bug #14789787)
• The Debug Sync facility could lose a signal, leading to a spurious ER_DEBUG_SYNC_TIMEOUT error.
(Bug #14765080, Bug #18221750)
• The mysql client allocated but did not free a string after reading each line in interactive mode,
resulting in a memory leak. (Bug #14685362)
• The optimizer trace could print ranges for key parts that were not usable for range access. (Bug
#14615536)
• Killing a connection while it was in the process of disconnecting could lead to an assertion being
raised, Valgrind warnings, and general unstability. (Bug #14560522)
• Passwords in statements were not obfuscated before being written to the audit log. (Bug #14536456)
• When running a query on INFORMATION_SCHEMA.INNODB_BUFFER_PAGE that requested
table_name and index_name values, query results would include index pages without
table_name or index_name values. (Bug #14529666)
• Several COM_xxx commands in the client-server protocol did not have length checks for incoming
network packets, which could result in various problems for malformed input. (Bug #14525642)
• If used to process a prepared CALL statement for a stored procedure with OUT or INOUT parameters,
mysql_stmt_store_result() did not properly set the flags required to retrieve all the result sets.
(Bug #14492429, Bug #17849978)
• INSERT ... ON DUPLICATE KEY UPDATE on a view could cause a server exit. (Bug #14261010)
• With the thread pool plugin in use, normal connection termination caused the Aborted_clients
status variable to be incremented. (Bug #14081240)
• A build failure occurred if HAVE_CRYPT was 0. (Bug #14036425)
• Grouping by an outer BLOB column in a subquery caused a server exit. (Bug #13966809, Bug
#14700180)
• On Windows, command-line options of the form --opt_name="opt_value" worked but
--opt_name='opt_value' did not.
On all platforms, for Performance Schema options of the form -performance_schema_instrument="instrument=value", invalid instrument names now are
rejected. (Bug #13955232)
• The server could exit after failing to handle an out-of-memory condition in
open_normal_and_derived_tables(). (Bug #13553905)
• The server could exit due to improper handling of the error from an invalid comparison. (Bug
#13009341)
293
MySQL 5.7 Release Notes
• MySQL Installer, if run in custom install or change mode, offered installation options that had no
effect. (Bug #12928601)
• Metadata returned for a prepared SELECT statement that had outer joins could indicate that columns
containing NULL values were NOT NULL. (Bug #12818811)
• The thread pool plugin produced an error message containing an incorrect maximum
thread_pool_prio_kickup_timer value. (Bug #12817590)
• For debug builds, the server could exit as a result of a series of statements that used a user variable
such that its character set/collation changed from statement to statement. (Bug #12368577)
• Incorrect results could be returned from queries that used several aggr_func(DISTINCT)
functions (where aggr_func() is an aggregate function such as COUNT()) when these referred to
different columns of the same composite key. (Bug #12328597)
• Queries of the form SELECT ... UNION SELECT ... ORDER BY were parsed incorrectly, with
the ORDER BY applied to the final SELECT rather than to the statement as a whole. (Bug #11886060)
• An identifier containing special characters could become too long after conversion of such characters
to encoded format, resulting in SQL errors or failure to find files. (Bug #11766880)
• The CMake check for unsigned time_t failed on all platforms. (Bug #11766815)
• mysql_convert_table_format ignored --engine or -e as a synonym for the --type option.
(Bug #11756950)
• mysqladmin debug causes the server to write debug information to the error log. On systems that
supported mallinfo(), the memory-status part of this output was incorrect in 64-bit environments
when mysqld consumed more than 4GB memory.
Now the server uses malloc_info() to obtain memory-status information. malloc_info() does
not report the memory that the glibc malloc() implementation internally allocates using mmap().
However, it does provide the memory usage information in all the memory arenas.
This bug fix also involves a change of output format. The server now writes memory information in
XML format rather than as plain text. Example:
Memory status:
<malloc version="1">
<heap nr="0">
<sizes>
<size from="33" to="33" total="1056" count="32"/>
<size from="65" to="65" total="65" count="1"/>
<size from="113" to="113" total="226" count="2"/>
<size from="129" to="129" total="2451" count="19"/>
<size from="145" to="145" total="290" count="2"/>
<size from="161" to="161" total="1288" count="8"/>
<size from="209" to="209" total="418" count="2"/>
</sizes>
<total type="fast" count="0" size="0"/>
<total type="rest" count="66" size="5794"/>
<system type="current" size="10833920"/>
<system type="max" size="10833920"/>
<aspace type="total" size="10833920"/>
<aspace type="mprotect" size="10833920"/>
</heap>
<total type="fast" count="0" size="0"/>
<total type="rest" count="66" size="5794"/>
<system type="current" size="10833920"/>
<system type="max" size="10833920"/>
<aspace type="total" size="10833920"/>
<aspace type="mprotect" size="10833920"/>
</malloc>
(Bug #11746658)
294
MySQL 5.7 Release Notes
• The DBUG_ENTER string for the THD::increment_questions_counter() function incorrectly
named the THD::increment_updates_counter() function. (Bug #69989, Bug #17297266)
• RPM packages did not provide lowercase tags for their contents. For example, a server RPM
indicated that it provided MySQL-server, but not mysql-server. (Bug #69830, Bug #17211588)
• If the WITH_SSL CMake option was specified with an incorrect path to the SSL installation or the path
to an unsupported (too old) SSL installation, the option was implicitly changed to the bundled value
and yaSSL was used instead. Now CMake exits with an error so the user knows that the option value
must be changed. (Bug #69744, Bug #17162055)
• When selecting a union of an empty result set (created with WHERE 1=0 or WHERE FALSE) with a
derived table, incorrect filtering was applied to the derived table. (Bug #69471, Bug #16961803)
References: This issue is a regression of: Bug #15848521.
• For queries with ORDER BY ... LIMIT, the optimizer could choose a nonordering index for table
access. (Bug #69410, Bug #16916596)
• If query_cache_type was disabled at startup to prevent the query cache from being enabled at
runtime, disabling query_cache_type at runtime generated a warning even though it was already
disabled. (Bug #69396, Bug #16906827)
• When an internal buffer was too small for the workload, the Performance Schema could spend a lot
of time in an internal spin loop attempting to allocate a memory buffer, and fail. (Bug #69382, Bug
#16945618)
• In the absence of SQL_CALC_FOUND_ROWS in the preceding query, FOUND_ROWS() should return
the number of rows in the result set, but this did not always happen if the query contained ORDER
BY. (Bug #69271, Bug #16827872)
• Full-text search on InnoDB tables failed on searches for words containing apostrophes. (Bug
#69216, Bug #16801781)
• The libmysql.dll library was missing several symbols: my_init,
mysql_client_find_plugin, mysql_client_register_plugin, mysql_load_plugin,
mysql_load_plugin_v, mysql_options4, and mysql_plugin_options. (Bug #69204, Bug
#16797982, Bug #62394)
• If an UPDATE containing a subquery caused a deadlock inside InnoDB, the deadlock was not
properly handled by the SQL layer. The SQL layer then tried to unlock the row after InnoDB rolled
back the transaction, raising an assertion inside InnoDB. (Bug #69127, Bug #16757869)
• FOUND_ROWS() could return an incorrect value if the preceding query used filesort. (Bug
#69119, Bug #16760474)
References: This issue is a regression of: Bug #68458.
• The optimizer could choose a poor execution plan for queries with ORDER BY ... LIMIT. (Bug
#69013, Bug #16697792)
• Some possible cases of memory use after being freed were fixed. Thanks to Jan Staněk for the
patch. (Bug #68918, Bug #16725945)
• Some LEFT JOIN queries with GROUP BY could return incorrect results. (Bug #68897, Bug
#16620047)
References: This issue is a regression of: Bug #11760517.
• Some errors could be handled by condition handlers only if they were raised by particular
statements, such as INSERT, but not if they were raised by other statements, like UPDATE. An
example would be the foreign-key error ER_NO_REFERENCED_ROW_2 which could be treated
differently, depending on which statement raised it. (Bug #68831, Bug #16587369)
295
MySQL 5.7 Release Notes
• When specified in an option file, the plugin-dir client option was ignored. (Bug #68800, Bug
#16680313)
• Comparison of a DATETIME value and a string did not work correctly for the utf8_unicode_ci
collation. (Bug #68795, Bug #16567381)
• When only counting events but not timing them, Performance Schema would report
MIN_TIMER_WAIT values as a large number instead of 0. (Bug #68768, Bug #16552425)
• Using range access with an index prefix could produce incorrect results. (Bug #68750, Bug
#16540042)
• Full-text search on InnoDB tables failed on searches for literal phrases combined with + or operators. (Bug #68720, Bug #16516193)
• For debug builds, metadata locking for CREATE TABLE ... SELECT could raise an assertion. (Bug
#68695, Bug #16503173)
• Compilation on Solaris using gcc produced incorrect builds for 32-bit systems. (Bug #68675)
• mysqld --help and mysqld --verbose --help performed unnecessary logging. (Bug #68578,
Bug #16442113)
• A new CMake option, WITH_EDITLINE, is provided to indicate whether to use the bundled or system
libedit/editline library. The permitted values are bundled (the default) and system.
WITH_EDITLINE replaces WITH_LIBEDIT, which has been removed. (Bug #68558, Bug
#16430208)
• Overhead for the skip_trailing_space() function was reduced. (Bug #68477, Bug #16395778)
• If Loose Index Scan was used to evaluate a query that compared an integer column to an integer
specified as a quoted string (for example, col_name = '1'), the query could return incorrect
results. (Bug #68473, Bug #16394084)
• Optimizations that used extended secondary keys (see Use of Index Extensions) worked only for
InnoDB, even for storage engines with the requisite underlying capabilities. (Bug #68469, Bug
#16391678)
• mysql_install_db incorrectly tried to create the mysql.innodb_table_stats and
mysql.innodb_index_stats tables if InnoDB was not available. (Bug #68438, Bug #16369955)
• BIT(0) is not a valid data type specification but was silently converted to BIT(1). Now an
ER_INVALID_FIELD_SIZE error occurs and the specification is rejected. (Bug #68419, Bug
#16358989)
• In a MySQL server newer than MySQL 5.5 using a nonupgraded mysql.user table (for which
mysql_upgrade had not been run), statements to set passwords caused a server exit due to a
faulty check for the password_expired column. (Bug #68385, Bug #16339767)
• Indexes on derived tables that were used during the first invocation of a stored procedure were not
used in subsequent invocations. (Bug #68350, Bug #16346367)
• If a function such as AES_DECRYPT() that requires SSL support failed, the error could affect later
calls to functions that require SSL support. (Bug #68340, Bug #16315767)
• For DELETE and UPDATE statements, EXPLAIN displayed NULL in the ref column for some cases
where const is more appropriate. (Bug #68299, Bug #16296268)
• The mysql client incorrectly used latin1 for certain comparisons even if started with a multibyte
default character set, resulting in a client crash. (Bug #68107, Bug #16182919)
• In option files, the server could misinterpret option settings if the value was given after the option
name with no = sign in between. (Bug #67740, Bug #15930031)
296
MySQL 5.7 Release Notes
• Performance of prepared DML statements containing ? parameter substitution markers was
improved under row-based logging format: Since the binary log in this case need not include the
statement text, and since the statement will not be forced to statement-based logging as some DDL
statements might be, there is no need to substitute ? markers to produce a statement suitable for
logging. (Bug #67676, Bug #16038776)
• ELT(LEAST(...),..) could return a non-NULL value even if LEAST() returned NULL. (Bug
#67578, Bug #16171537)
• If the server could not find the errmsg.sys file at startup, the resulting error message did not
indicate which configuration parameter to check. (Bug #67576, Bug #15880018)
• mysqldump wrote SET statements as SET OPTION, which failed when reloaded because the
deprecated OPTION keyword has been removed from SET syntax. (Bug #67507, Bug #15844882)
• For failure to create a new thread for the event scheduler, event execution, or new connection, no
message was written to the error log. This could lead to the impression that the event scheduler was
running normally when it was not. (Bug #67191, Bug #14749800, Bug #16865959)
• Configuring with cmake -DWITHOUT_SERVER to build clients without the server failed for builds
outside of the source tree. (Bug #66000, Bug #14367046)
• mysqldump assumed the existence of the general_log and slow_log tables in the mysql
database. It failed if invoked to dump tables from an older server where these tables do not exist.
(Bug #65670, Bug #14236170)
• If an account had a nonzero MAX_USER_CONNECTIONS value, that value was not always respected.
(Bug #65104, Bug #14003080)
• Attempts to build from a source RPM package could fail because the build process attempted to refer
to a pb2user that might not exist. (Bug #64641, Bug #13865797, Bug #69339, Bug #16874980)
• When an ALTER TABLE operation was performed with an invalid foreign key constraint, the error
reported was ER_CANT_CREATE_TABLE rather than ER_CANNOT_ADD_FOREIGN. (Bug #64617, Bug
#13840553)
• If one session had any metadata lock on a table, another session attempting CREATE TABLE
[IF NOT EXISTS] for the same table would hang. This occurred due to an attempt in the second
session to acquire an exclusive metadata lock on the table before checking whether the table already
existed. An exclusive metadata lock is not compatible with any other metadata locks, so the session
hung for the lock timeout period if another session had the table locked.
Now the server attempts to acquire a shared metadata lock on the table first to check whether
it exists, then upgrade to an exclusive lock if it does not. If the table does exist, an error occurs
for CREATE TABLE and a warning for CREATE TABLE IF NOT EXISTS. (Bug #63144, Bug
#13418638)
• sql-common/client_plugin.c contained a nonportable use of a va_list parameter. (Bug
#62769, Bug #13252623)
• InnoDB does not support full-text parser plugins, but failed to report an error if they were specified.
Now an ER_INNODB_NO_FT_USES_PARSER error is returned. (Bug #62004, Bug #12843070)
• The url columns in the mysql datatbase help tables were too short to hold some of the URLs in
the help content. These columns are now created as type TEXT to accommodate longer URLs. (Bug
#61520, Bug #12671635)
• A typo in cmake/dtrace.cmake prevented DTrace support from being enabled by DENABLE_DTRACE-on. (Bug #60743, Bug #12325449)
• The Turbo Boyer-Moore algorithm used for LIKE pattern matches failed to handle some patterns.
The server now uses the original Boyer-Moore algorithm. (Bug #59973, Bug #11766777)
297
MySQL 5.7 Release Notes
• Boolean plugin system variables did not behave well on machines where char is unsigned; some
code attempted to assign a negative value to these. (Bug #59905, Bug #11864205)
• Some subquery transformations were not visible in EXPLAIN output. (Bug #59852, Bug #11766685)
• Configuring MySQL with -DWITH_EXTRA_CHARSETS=none caused a build failure. (Bug #58672,
Bug #11765682)
• Two problems adding or subtracting keyword from the current debug system variable setting were
corrected:
• A debug value of 'd' means “all debug macros enabled”. The following sequence left the value in
an incorrect state:
mysql> SET debug = 'd';SELECT @@debug;
+---------+
| @@debug |
+---------+
| d
|
+---------+
mysql> SET debug = '+d,M1';SELECT @@debug;
+---------+
| @@debug |
+---------+
| d,M1
|
+---------+
The first SET statement enables all debug macros. The second SET should add the M1 macro to
the current set, which should result in no change because the current set is already “all macros”.
Instead, the second SET reset the current set to only the M1 macro, effectively disabling all others.
The server now correctly leaves debug set to 'd'.
• A debug value of '' means “no debug macros enabled”. The following sequence left the value in
an incorrect state:
mysql> SET debug = 'd,M1';SELECT @@debug;
+---------+
| @@debug |
+---------+
| d,M1
|
+---------+
mysql> SET debug = '-d,M1';SELECT @@debug;
+---------+
| @@debug |
+---------+
| d
|
+---------+
The first SET statement sets debug to the M1* macro. The second SET should subtract the M1
macro from the current set, leaving no debug macros enabled. Instead, the second SET reset the
current set to 'd' (all macros enabled). The server now correctly sets debug to ''.
(Bug #58630, Bug #11765644)
• It is now possible to suppress installation of the mysql-test directory after compiling MySQL from
source by invoking CMake with the INSTALL_MYSQLTESTDIR option explicitly set to empty:
cmake . -DINSTALL_MYSQLTESTDIR=
Previously, attempts to do this resulted in an error. (Bug #58615, Bug #11765629)
298
MySQL 5.7 Release Notes
• On 64-bit OS X systems, CMake used x86 rather than x86_64 when determining the machine type.
(Bug #58462, Bug #11765489)
• Long table or column names could cause mysqlshow to exit. (Bug #53956, Bug #11761458)
• With big_tables enabled, queries that used COUNT(DISTINCT) on a simple join with a constant
equality condition on a non-duplicate key returned incorrect results. (Bug #52582, Bug #11760197)
References: See also: Bug #18853696.
• The !includedir directive in option files did not read .cnf or .ini files that included a dot in the
file name preceding the extension. (Bug #51609, Bug #11759306)
• Successful queries served from the query cache did not clear warnings. (Bug #49634, Bug
#11757567)
• If ALTER TABLE was used to set the default value for a TIMESTAMP or DATETIME column that
had CURRENT_TIMESTAMP as its default when it was created, the new default was not shown by
SHOW CREATE TABLE, and incorrect values could be inserted into the column. (Bug #45669, Bug
#11754116, Bug #76610, Bug #20848203)
• IF() function evaluations could produce different results when executed in a prepared versus
nonprepared statement. (Bug #45370, Bug #11753852)
• The range optimizer used the wrong prerequisite for concluding that a table is the inner table of an
outer join. This led to incorrect cost estimates and choice of the wrong index for query processing.
(Bug #37333, Bug #11748775)
• For better robustness against stack overflow, the server now accounts for the size of the guard area
when making thread stack size requests. (Bug #35019, Bug #11748074)
• If mysqld crashed during a shutdown initiated by /etc/init.d/mysql stop, mysqld_safe
restarted mysqld when it should not have. (Bug #34084, Bug #13864548)
• mysql.h no longer defines __WIN__ on Windows, and the MySQL sources have been changed to
test for _WIN32 instead. (Bug #20338, Bug #11745828)
Changes in MySQL 5.7.1 (2013-04-23, Milestone 11)
Note
This is a milestone release, for use at your own risk. Upgrades between
milestone releases (or from a milestone release to a GA release) are not
supported. Significant development changes take place in milestone releases
and you may encounter compatibility issues, such as data format changes that
require attention in addition to the usual procedure of running mysql_upgrade.
For example, you may find it necessary to dump your data with mysqldump
before the upgrade and reload it afterward.
• Audit Log Notes
• Functionality Added or Changed
• Bugs Fixed
Audit Log Notes
• Several changes were made to the audit log plugin for better compatibility with Oracle Audit Vault.
The format of the audit log file has changed:
• Information within <AUDIT_RECORD> elements written in the old format using attributes is written
in the new format using subelements.
299
MySQL 5.7 Release Notes
• The new format includes more information in <AUDIT_RECORD> elements. Every element includes
a RECORD_ID value providing a unique identifier. The TIMESTAMP value includes time zone
information. Query records include HOST, IP, OS_LOGIN, and USER information, as well as
COMMAND_CLASS and STATUS_CODE values.
The STATUS_CODE value differs from the existing STATUS value: STATUS_CODE is 0 for success
and 1 for error, which is compatible with the EZ_collector consumer for Audit Vault. STATUS is the
value of the mysql_errno() C API function. This is 0 for success and nonzero for error, and thus
is not necessarily 1 for error.
Example of old <AUDIT_RECORD> format:
<AUDIT_RECORD
TIMESTAMP="2013-04-15T15:27:27" NAME="Query" CONNECTION_ID="3" STATUS="0" SQLTEXT="SELECT 1" />
Example of new <AUDIT_RECORD> format:
<AUDIT_RECORD>
<TIMESTAMP>2013-04-15T15:27:27 UTC</TIMESTAMP>
<RECORD_ID>3998_2013-04-15T15:27:27</RECORD_ID>
<NAME>Query</NAME>
<CONNECTION_ID>3</CONNECTION_ID>
<STATUS>0</STATUS>
<STATUS_CODE>0</STATUS_CODE>
<USER>root[root] @ localhost [127.0.0.1]</USER>
<OS_LOGIN></OS_LOGIN>
<HOST>localhost</HOST>
<IP>127.0.0.1</IP>
<COMMAND_CLASS>select</COMMAND_CLASS>
<SQLTEXT>SELECT 1</SQLTEXT>
</AUDIT_RECORD>
When the audit log plugin rotates the audit log file, it uses a different file name format. For a log file
named audit.log, the plugin previously renamed the file to audit.log.TIMESTAMP. The plugin
now renames the file to audit.log.TIMESTAMP.xml to indicate that it is an XML file.
For information about the audit log plugin, see MySQL Enterprise Audit.
If you previously used an older version of the audit log plugin, use this procedure to avoid writing
new-format log entries to an existing log file that contains old-format entries:
1. Stop the server.
2. Rename the current audit log file manually. This file will contain only old-format log entries.
3. Update the server and restart it. The audit log plugin will create a new log file, which will contain
only new-format log entries.
The API for writing audit plugins has also changed. The mysql_event_general structure has
new members to represent client host name and IP address, command class, and external user. For
more information, see Writing Audit Plugins.
Functionality Added or Changed
• Incompatible Change: SHOW ENGINE PERFORMANCE_SCHEMA STATUS output used a mix of
row_count and count attributes. These are now all count. Similarly, the output used a mix of
row_size and size attributes. These are now all size. (Bug #16165468)
• Performance: String hashing overhead was reduced. This also improves performance for metadata
locking, the table definition cache, and Performance Schema table I/O and file I/O instrumentation.
(Bug #13944392)
300
MySQL 5.7 Release Notes
• InnoDB: Added a separate tablespace for all non-compressed InnoDB temporary tables. The new
tablespace is always recreated on server startup.
The new tablespace, ibtmp1, is located in the MySQL data directory ( datadir) by default. A
newly added configuration file option, innodb_temp_data_file_path, allows for a user-defined
temporary data file path. For related information, see Temporary Table Undo Logs.
• InnoDB: Prior to this release, InnoDB stored spatial data types as binary BLOB data, mapped to the
internal DATA_BLOB data type. BLOB remains the underlying data type but spatial data types are now
mapped to a new internal data type, DATA_GEOMETRY. With BLOB as the underlying data type, a
prefix index can still be used on all GEOMETRY data type columns.
• InnoDB: InnoDB temporary table metadata is no longer stored in InnoDB system tables. Instead, a
new INFORMATION_SCHEMA table, INNODB_TEMP_TABLE_INFO, provides users with a snapshot
of active temporary tables. The table contains metadata and reports on all user and system-created
temporary tables that are active within a given InnoDB instance.
• InnoDB: DDL performance for InnoDB temporary tables is improved through optimization of
CREATE TABLE, DROP TABLE, TRUNCATE TABLE, and ALTER TABLE statements. Optimizations
were achieved by limiting actions performed by DDL statements to only those necessary for
temporary tables.
• InnoDB: VARCHAR size may be increased using an in-place ALTER TABLE, as in this example:
ALTER TABLE t1 ALGORITHM=INPLACE, CHANGE COLUMN c1 c1 VARCHAR(255);
This is true as long as the number of length bytes required by a VARCHAR column remains the same.
For VARCHAR values of 0 to 255, one length byte is required to encode the value. For VARCHAR
values of 256 bytes or more, two length bytes are required. As a result, in-place ALTER TABLE
only supports increasing VARCHAR size from 0 to 255 bytes or increasing VARCHAR size from a
value equal to or greater than 256 bytes. In-place ALTER TABLE does not support increasing
VARCHAR size from less than 256 bytes to a value equal to or greater than 256 bytes. In this case,
the number of required length bytes would change from 1 to 2, which is only supported by a table
copy (ALGORITHM=COPY).
Decreasing VARCHAR size using in-place ALTER TABLE is not supported. Decreasing VARCHAR size
requires a table copy (ALGORITHM=COPY).
For additional details, refer to the “Column Properties” information in Online DDL Overview.
• InnoDB: Online index renaming is supported by ALTER TABLE, which now includes a RENAME
INDEX clause, as shown in the following example: “ALTER TABLE t RENAME INDEX i1 TO i2”,
where i1 is the current name of the index and i2 is the new name.
The result of “ALTER TABLE t RENAME INDEX i1 TO i2” would be a table with contents and
structure that is identical to the old version of “t1” except for the index name, which is now “i2”
instead of “i1”.
• Partitioning: HANDLER statements are now supported with partitioned tables.
• Replication: An Auto_Position column has been added to the output generated by SHOW
SLAVE STATUS. The value of this column shows whether replication autopositioning is in use. If
autopositioning is enabled—that is, if MASTER_AUTO_POSITION = 1 was set by the last successful
CHANGE MASTER TO statement that was executed on the slave—then the column's value is 1; if not,
then the value is 0. (Bug #15992220)
• Replication: The functions GTID_SUBTRACT() and GTID_SUBSET() were formerly available in
libmysqld only when it was built with replication support. Now these functions are always available
when using this library, regardless of how it was built.
301
MySQL 5.7 Release Notes
• Replication: Added the --rewrite-db option for mysqlbinlog, which allows mysqlbinlog to
rewrite the names of databases when playing back binary logs written using the row-based logging
format. Multiple rewrite rules can be created by specifying the option multiple times.
• MySQL no longer uses the default OpenSSL compression. (Bug #16235681)
• There is now a distinct error code (ER_MUST_CHANGE_PASSWORD_LOGIN) for the error sent by the
server to a client authenticating with an expired password. (Bug #16102943)
• In RPM packages built for Unbreakable Linux Network, libmysqld.so now has a version number.
(Bug #15972480)
• Error messages for ALTER TABLE statement using a LOCK or ALGORITHM value not supported for
the given operation were very generic. The server now produces more informative messages. (Bug
#15902911)
• If a client with an expired password connected but old_passwords was not the value required
to select the password hashing format appropriate for the client account, there was no way for the
client to determine the proper value. Now the server automatically sets the session old_passwords
value appropriately for the account authentication method. For example, if the account uses the
sha256_password authentication plugin, the server sets old_passwords=2. (Bug #15892194)
• mysqldump now supports an --ignore-error option. The option value is a comma-separated list
of error numbers specifying the errors to ignore during mysqldump execution. If the --force option
is also given to ignore all errors, --force takes precedence. (Bug #15855723)
• mysql_config_editor now supports --port and --socket options for specifying TCP/IP port
number and Unix socket file name. (Bug #15851247)
• mysqlcheck has a new --skip-database option. The option value is the name of a database
(case sensitive) for which checks should be skipped.
mysql_upgrade adds this option to mysqlcheck commands that it generates to upgrade the
system tables in the mysql database before tables in other databases: It upgrades the mysql
database, then all databases except the mysql database. This avoids problems that can occur if
user tables are upgraded before the system tables. (Bug #14697538, Bug #68163, Bug #16216384)
• The validate_password_policy_number system variable was renamed to
validate_password_policy. (Bug #14588121)
• Previously, on Linux the server failed to perform stack backtrace attempts for versions of glibc
older than the current minimum supported version (2.3). Now on such attempts the server displays a
message that the glibc version is too old to support backtracing. (Bug #14475946)
• In JSON-format EXPLAIN output, the attached_condition information for subqueries now
includes select# to indicate the relative order of subquery execution. (Bug #13897507)
• The following changes were made to the sandbox mode that the server uses to handle client
connections for accounts with expired passwords:
• There is a new disconnect_on_expired_password system variable (default: enabled). This
controls how the server treats expired-password accounts.
• Two flags were added to the C API client library:
MYSQL_OPT_CAN_HANDLE_EXPIRED_PASSWORDS for mysql_options() and
CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS for mysql_real_connect(). Each flag enables
a client program to indicate whether it can handle sandbox mode for accounts with expired
passwords.
MYSQL_OPT_CAN_HANDLE_EXPIRED_PASSWORDS is enabled for mysqltest unconditionally, for
mysql in interactive mode, and for mysqladmin if the first command is password.
302
MySQL 5.7 Release Notes
For more information about how the client-side flags interact with
disconnect_on_expired_password, see Password Expiration and Sandbox Mode. (Bug
#67568, Bug #15874023)
• If a user attempted to access a nonexistent column for which the user had no access, the server
returned an error indicating that the column did not exist. Now the server returns an error indicating
that the user does not have privileges for the column, which provides no information about column
existence. (Bug #19947, Bug #11745788)
• The MySQL test suite mysql-test-run.sh program now starts the server with InnoDB rather than
MyISAM as the default storage engine. To maintain compatibility of test results with existing result
files, test cases were modified to add a line that includes the force_default_myisam.inc file as
necessary. In a future release, for those test cases not specifically requiring MyISAM, that line will be
removed (so they run with InnoDB) and test results will be updated.
• ALTER TABLE now supports a RENAME INDEX clause that renames an index. The change is made
in place without a table-copy operation.
• The mysql client now has a --syslog option that causes interactive statements to be sent to the
system syslog facility. Logging is suppressed for statements that match the default “ignore” pattern
list ("*IDENTIFIED*:*PASSWORD*"), as well as statements that match any patterns specified
using the --histignore option. For more information, see mysql Logging.
• The deprecated innodb_mirrored_log_groups system variable has been removed.
Bugs Fixed
• Incompatible Change; Partitioning: Changes in the KEY partitioning hashing functions used with
numeric, date and time, ENUM, and SET columns in MySQL 5.5 makes tables using partitioning or
subpartitioning by KEY on any of the affected column types and created on a MySQL 5.5 or later
server incompatible with a MySQL 5.1 server. This is because the partition IDs as calculated by a
MySQL 5.5 or later server almost certainly differ from those calculated by a MySQL 5.1 server for the
same table definition and data as a result of the changes in these functions.
The principal changes in the KEY partitioning implementation in MySQL 5.5 resulting in this issue
were as follows: 1. The hash function used for numeric and date and time columns changed from
binary to character-based. 2. The base used for hashing of ENUM and SET columns changed from
latin1 ci characters to binary.
The fix involves adding the capability in MySQL 5.5 and later to choose which type of hashing
to use for KEY partitioning, which is implemented with a new ALGORITHM extension to the
PARTITION BY KEY option for CREATE TABLE and ALTER TABLE. Specifying PARTITION BY
KEY ALGORITHM=1 ([columns]) causes the server to use the hashing functions as implemented
in MySQL 5.1; using ALGORITHM=2 causes the server to use the hashing functions from MySQL 5.5
and later. ALGORITHM=2 is the default. Using the appropriate value for ALGORITHM, you can perform
any of the following tasks:
• Create KEY partitioned tables in MySQL 5.5 and later that are compatible with MySQL 5.1, using
CREATE TABLE ... PARTITION BY KEY ALGORITHM=1 (...).
• Downgrade KEY partitioned tables that were created in MySQL 5.5 or later to become compatible
with MySQL 5.1, using ALTER TABLE ... PARTITION BY KEY ALGORITHM=1 (...).
• Upgrade KEY partitioned tables originally created in MySQL 5.1 to use hashing as in MySQL 5.5
and later, using ALTER TABLE ... PARTITION BY KEY ALGORITHM=2 (...).
Important: After such tables are upgraded, they cannot be used any longer with MySQL 5.1 unless
they are first downgraded again using ALTER TABLE ... PARTITION BY KEY ALGORITHM=1
(...) on a MySQL server supporting this option.
303
MySQL 5.7 Release Notes
This syntax is not backward compatible, and causes errors in older versions of the MySQL server.
When generating CREATE TABLE ... PARTITION BY KEY statements, mysqldump brackets
any occurrence of ALGORITHM=1 or ALGORITHM=2 in conditional comments such that it is ignored
by a MySQL server whose version is not at least 5.5.31. An additional consideration for upgrades
is that MySQL 5.6 servers prior to MySQL 5.6.11 do not ignore the ALGORITHM option in such
statements when generated by a MySQL 5.5 server, due to the that the conditional comments refer
to version 5.5.31; in this case, you must edit the dump manually and remove or comment out the
option wherever it occurs before attempting to load it into a MySQL 5.6.10 or earlier MySQL 5.6
server. This is not an issue for dumps generated by MySQL 5.6.11 or later version of mysqldump,
where the version used in such comments is 5.6.11. For more information, see ALTER TABLE
Partition Operations.
As part of this fix, a spurious assertion by InnoDB that a deleted row had previously been read,
causing the server to assert on delete of a row that the row was in the wrong partition, was also
removed. (Bug #14521864, Bug #66462, Bug #16093958, Bug #16274455)
References: See also: Bug #11759782.
• Incompatible Change: For debug builds, creating an InnoDB table in strict SQL mode that violated
the maximum key length limit caused the server to exit.
A behavior change in consequence of this bug fix: In strict SQL mode, a