Oracle 12c Release 2 12.2 database software Administrator's Reference
Reklama
Reklama
Oracle
®
Database
Administrator's Reference
12c Release 2 (12.2) for Linux and UNIX-Based Operating
Systems
E49960-17
July 2017
Oracle Database Administrator's Reference, 12c Release 2 (12.2) for Linux and UNIX-Based Operating
Systems
E49960-17
Copyright
©
2006, 2017, Oracle and/or its affiliates. All rights reserved.
Primary Author: Bharathi Jayathirtha
Contributing Authors: Kevin Flood, Pat Huey, Clara Jaeckel, Emily Murphy, Terri Winters, Prakash Jashnani,
Tanaya Bhattacharjee
Contributors: Subhranshu Banerjee, Mark Bauer, Robert Chang, Jonathan Creighton, Sudip Datta,
Thirumaleshwara Hasandka, Joel Kallman, George Kotsovolos, Richard Long, Rolly Lv, Padmanabhan
Manavazhi, Matthew Mckerley, Krishna Mohan, Rajendra Pingte, Hanlin Qian, Janelle Simmons, Roy
Swonger, Douglas Williams, Joseph Therrattil Koonen, Binoy Sukumaran, and Sumanta Chatterjee.
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Contents
Preface
Changes in This Release for Oracle Database Administrator's Reference
1 Administering Oracle Database
1.3.3 PROCESSOR_GROUP_NAME Initialization Parameter ................................................
2 Stopping and Starting Oracle Software
2.1.1 Stopping and Starting Oracle Database and Oracle Automatic Storage
iii
3 Configuring Oracle Database
4 Administering SQL*Plus
5 Configuring Oracle Net Services
6 Using Oracle Precompilers and the Oracle Call Interface
iv
7 SQL*Loader and PL/SQL Demonstrations
8 Tuning Oracle Database
v
8.5.2 Using Disk Resync to Monitor Automatic Storage Management Disk Group ..........
8.6.4 Shared Memory on IBM AIX on POWER Systems (64-Bit)...........................................
A Administering Oracle Database on Oracle Solaris
A.1.6 How Oracle Database Decides Between OSM, ISM and DISM.....................................
B Administering Oracle Database on Linux
vi
C Administering Oracle Database on IBM AIX on POWER Systems (64-Bit)
C.2.1 IBM AIX on POWER Systems (64-Bit) Logical Volume Manager.................................
C.2.2 Using Journaled File Systems Compared to Raw Logical Volumes .............................
C.2.5 Using the DB_FILE_MULTIBLOCK_READ_COUNT Parameter.................................
C.6 Configuring IBM Java Secure Socket Extension Provider with Oracle JDBC Thin Driver
D Administering Oracle Database on HP-UX
D.6 CPU_COUNT Initialization Parameter and HP-UX Dynamic Processor Reconfiguration
E Using Oracle ODBC Driver
vii
F Database Limits
Index
viii
Preface
This guide provides platform-specific information about administering and configuring Oracle Database 12c Release 2 (12.2) on the following platforms:
• Oracle Solaris
• Linux
• IBM AIX on POWER Systems (64-Bit)
• HP-UX Itanium
This guide supplements the Oracle Database Administrator's Guide.
Audience
This guide is intended for anyone responsible for administering and configuring
Oracle Database 12c Release 2 (12.2). If you are configuring Oracle RAC, then refer to
Oracle Real Application Clusters Administration and Deployment Guide
.
Documentation Accessibility
For information about Oracle's commitment to accessibility, visit the Oracle
Accessibility Program website at http://www.oracle.com/pls/topic/lookup?
ctx=acc&id=docacc .
Access to Oracle Support
Oracle customers that have purchased support have access to electronic support through My Oracle Support. For information, visit http://www.oracle.com/pls/ topic/lookup?ctx=acc&id=info or visit http://www.oracle.com/pls/topic/lookup?
ctx=acc&id=trs if you are hearing impaired.
Related Documentation
For important information, refer to your platform-specific Release Notes, Installation
Guides, and Examples Installation Guide in the Oracle Database Documentation Library.
Conventions
The following text conventions are used in this document:
ix
x
Convention boldface
italic
monospace
Meaning
Boldface type indicates graphical user interface elements associated with an action, or terms defined in text or the glossary.
Italic type indicates book titles, emphasis, or placeholder variables for which you supply particular values.
Monospace type indicates commands within a paragraph, URLs, code in examples, text that appears on the screen, or text that you enter.
Command Syntax
UNIX command syntax appears in monospace
font. The dollar character ($), number sign (#), or percent character (%) are UNIX command prompts. Do not enter them as part of the command. The following command syntax conventions are used in this guide:
Convention
backslash \ braces { } brackets [ ] ellipses ...
italic
vertical line |
Description
A backslash is the UNIX command continuation character. It is used in command examples that are too long to fit on a single line. Enter the command as displayed (with a backslash) or enter it on a single line without a backslash: dd if=/dev/rdsk/c0t1d0s6 of=/dev/rst0 bs=10b \ count=10000
Braces indicate required items:
.DEFINE {macro1}
Brackets indicate optional items: cvtcrt termname [outfile]
Ellipses indicate an arbitrary number of similar items:
CHKVAL fieldname value1 value2 ... valueN
Italic type indicates a variable. Substitute a value for the variable:
library_name
A vertical line indicates a choice within braces or brackets:
FILE filesize [K|M]
Terminology
The names of some UNIX operating systems have been shortened in this guide. These are:
Operating System
Oracle Solaris on SPARC (64-
Bit)
Oracle Solaris on x86-64 (64–
Bit)
Abbreviated Name
Oracle Solaris
Note:
Where the information for Oracle Solaris is different on a particular architecture, this is noted in the text.
Linux x86-64
Linux
Note:
Where the information for Linux is different on a particular architecture, this is noted in the text.
Accessing Documentation
The documentation for this release includes platform-specific documentation and generic product documentation. Platform-specific documentation includes information about installing, configuring, and using Oracle products on a particular platform. The documentation is available in Adobe portable document format (PDF) and HTML format.
All Oracle documentation is available at the following URL: http://docs.oracle.com/en/
Note:
Platform-specific documentation is current at the time of release. For the latest information, Oracle recommends you to go to Oracle Technology Network website.
xi
Changes in This Release for Oracle
Database Administrator's Reference
This preface contains:
•
Changes in Oracle Database 12c Release 2 (12.2)
(page xiii)
Changes in Oracle Database 12c Release 2 (12.2)
This section describes changes in Oracle Database Administrator's Reference for Linux and
UNIX-Based Operating Systems
for Oracle Database 12c Release 2 (12.2).
•
(page xiii)
New Features
The following is a list of new features or enhancements provided with Oracle
Database 12c Release 2 (12.2):
• New Administrator Role
Oracle Database 12c Release 2 (12.2) provides support for separation of duty for
Oracle Database by introducing the
SYSRAC
role for Oracle Real Application
Clusters (Oracle RAC) management.
SYSRAC
, like
SYSDG
,
SYSBACKUP
, and
SYSKM
, enables you to enforce separation of duty and reduce reliance on the use of
SYSDBA
on production systems. The
SYSRAC
role is the default mode and is assigned only the priveleges required for connecting to the database by the clusterware agent on behalf of the Oracle RAC utilities such as srvctl
.
Assigning a separate role for administering Oracle RAC (
SYSRAC
) improves the security of the Oracle database and reduces reliance on the
SYSDBA
role to administer Oracle RAC.
SYSRAC
adds to the roles
SYSKM
,
SYSDG
, and
SYSBACKUP
in release 12.1 that can administer key management, Oracle Data
Guard, and RMAN backup respectively. With these administrative roles, customers can implement separation of duty in their environment according to their business needs. For example, customers can create a named administrative account and grant only the administrative roles needed such as
SYSRAC
and
SYSDG
to manage both Oracle RAC and Oracle Data Guard configurations.
xiii
xiv
See Also:
–
Oracle Database Administrator's Guide
for more information about the
OSDBA
,
OSOPER
,
OSBACKUP
,
OSDG
, and
OSKM
groups, and the
SYSDBA
,
SYSOPER
,
SYSBACKUP
,
SYSDG
,
SYSKM
, and
SYSRAC
roles
–
Oracle Automatic Storage Management Administrator's Guide
for more information about
OSASM
and
SYSASM
–
Oracle Database Security Guide
–
Oracle Database Installation Guide for Linux
1
Administering Oracle Database
This chapter provides information about administering Oracle Database on UNIXbased operating systems. It contains the following sections:
•
•
Environment Variables (page 1-1)
•
(page 1-7)
•
Managing Diagnostic Data (page 1-9)
See Also:
• The appropriate appendix in this guide for platform-specific information about administering Oracle Database
•
Oracle Database Administrator's Guide
and Database 2 Day DBA for generic information about administering Oracle Database
1.1 Overview
You must set Oracle Database environment variables, parameters, and user settings for Oracle Database to work. This chapter describes the various settings for Oracle
Database.
In Oracle Database files and programs, a question mark (?) represents the value of the
ORACLE_HOME
environment variable. For example, Oracle Database expands the question mark in the following SQL statement to the full path of the Oracle home directory:
SQL> ALTER TABLESPACE TEMP ADD DATAFILE '?/dbs/temp02.dbf' SIZE 200M
Similarly, the at sign (@) represents the
ORACLE_SID
environment variable. For example, to indicate a file that belongs to the current instance, run the following command:
SQL> ALTER TABLESPACE tablespace_name ADD DATAFILE [email protected]
1.2 Environment Variables
This section describes the most commonly used Oracle Database and operating system environment variables. You must define some environment variables before installing
Oracle Database. This section covers the following topics:
•
Oracle Database Environment Variables
(page 1-2)
Administering Oracle Database 1-1
Environment Variables
•
Linux and UNIX Environment Variables (page 1-4)
•
Setting a Common Environment (page 1-6)
•
Setting the System Time Zone (page 1-7)
To display the current value of an environment variable, use the env
command. For example, to display the value of the
ORACLE_SID
environment variable, run the following command:
$ env | grep ORACLE_SID
To display the current value of all environment variables, run the env
command as follows:
$ env | more
1.2.1 Oracle Database Environment Variables
The following table describes some environment variables used with Oracle Database.
Table 1-1 Oracle Database Environment Variables
Variable
NLS_LANG
ORA_NLS10
ORA_TZFILE
ORACLE_BASE
Definition
Function: Specifies the language, territory, and character set of the client environment. The client character set specified by
NLS_LANG
must match the character set of the terminal or terminal emulator. If required,
NLS_LANG
can be temporarily reset to another character set before starting a non-interactive batch program to match the character set of files and scripts processed by this program. The character set specified by
NLS_LANG
can be different from the database character set, in which case the character set is automatically converted.
Refer to Oracle Database Globalization Support Guide for a list of parameters for this variable.
Syntax:
language_territory.characterset
Example: french_france.we8iso8859p15
Function: Specifies the directory where the language, territory, character set, and linguistic definition files are stored.
Syntax:
directory_path
Example:
$ORACLE_HOME/nls/data
Function: Specifies the full path and file name of the time zone file. The Oracle
Database Server always uses the large time zone file (
$ORACLE_HOME/ oracore/zoneinfo/timezlrg_number.dat
). If you want to use the small time zone file on the client side, you must set this environment variable to the full path of the small time zone file (
$ORACLE_HOME/oracore/zoneinfo/ timezone_number.dat
). If you use the small time zone file on the client side, you must ensure that the database you access contains data only in the time zone regions recognized by the small time zone file.
Syntax:
directory_path
Example:
$ORACLE_HOME/oracore/zoneinfo/timezlrg_11.dat
Function: Specifies the base of the Oracle directory structure for Optimal
Flexible Architecture compliant installations.
Syntax:
directory_path
Example:
/u01/app/oracle
1-2 Oracle Database Administrator's Reference
Environment Variables
Table 1-1 (Cont.) Oracle Database Environment Variables
Variable
ORACLE_HOME
ORACLE_PATH
ORACLE_SID
ORACLE_TRACE
ORAENV_ASK
SQLPATH
TNS_ADMIN
Definition
Function: Specifies the directory containing the Oracle software.
Syntax:
directory_path
Example:
$ORACLE_BASE/product/12.2.0/dbhome_1
Function: Specifies the search path for files used by Oracle applications such as
SQL*Plus. If the full path to the file is not specified, or if the file is not in the current directory, then the Oracle application uses
ORACLE_PATH
to locate the file.
Syntax: Colon-separated list of directories:
directory1:directory2:directory3
Example:
/u01/app/oracle/product/12.2.0/dbhome_1/bin:
Function: Specifies the Oracle system identifier.
Syntax: A string of numbers and letters that must begin with a letter. Oracle recommends a maximum of 8 characters for system identifiers. For more information about this environment variable, refer to Oracle Database Installation
Guide
.
Example:
SAL1
Function: Enables the tracing of shell scripts during an installation. If it is set to
T
, then many Oracle shell scripts use the set -x
command, which prints commands and their arguments as they are run. If it is set to any other value, or no value, then the scripts do not use the set -x
command.
Syntax:
T
or not
T
Example:
T
Function: Controls whether the oraenv
or coraenv
script prompts or does not prompt for the value of the
ORACLE_SID
environment variable. If it is set to
NO
, then the scripts do not prompt for the value of the
ORACLE_SID
environment variable. If it is set to any other value, or no value, then the scripts prompt for a value for the
ORACLE_SID
environment variable.
Syntax:
NO
or not
NO
Example:
NO
Function: Specifies the directory or list of directories that SQL*Plus searches for a login.sql
file.
Syntax: Colon-separated list of directories:
directory1:directory2:directory3
Example:
/home:/home/oracle:/u01/oracle
Function: Specifies the directory containing the Oracle Net Services configuration files.
Syntax:
directory_path
Example:
$ORACLE_HOME/network/admin
Administering Oracle Database 1-3
Environment Variables
Table 1-1 (Cont.) Oracle Database Environment Variables
Variable
TWO_TASK
NLS_OS_CHARSET
Definition
Function: Specifies the default connect identifier to use in the connect string. If this environment variable is set, then do not specify the connect identifier in the connect string. For example, if the
TWO_TASK
environment variable is set to sales
, then you can connect to a database by using the following command:
SQL> CONNECT username
Enter password: password
Syntax: Any connect identifier.
Range of Values: Any valid connect identifier that can be resolved by using a naming method, such as a tnsnames.ora
file or a directory server.
Example:
PRODDB_TCP
Function: Specifies the Oracle character set name corresponding to the UNIX locale character set in which the file names and user names are encoded by the operating system. You must set the environment variable
NLS_OS_CHARSET,
if the UNIX locale character set is different from the Oracle client character set.
These two character sets may differ, for example, if
NLS_LANG
is set to a particular character set used to encode an SQL script, which is to be executed in an SQL*Plus session. Usually, the Oracle client character set and the operating system character set are the same and
NLS_OS_CHARSET
must not be set.
Syntax:
characterset
Example:
WE8ISO8859P1
Note:
• To prevent conflicts, do not define environment variables with names that are identical to the names of Oracle Database server processes. For example
ARCH
,
PMON
, and
DBWR
.
• If the Oracle installation owner ( oracle
user) environment variables are missing, or if they are set to incorrect paths, then you may encounter undefined errors during Oracle Database startup. Ensure that all the environment variables are correctly set before starting the database. Refer to My Oracle Support Note 373303.1 for more information: https://support.oracle.com/epmos/faces/DocumentDisplay?
id=373303.1
Caution:
You must consult Oracle Support before you implement any changes as suggested in the My Oracle Support Note 373303.1.
1.2.2 Linux and UNIX Environment Variables
Oracle Database uses operating system environment variables to define system resources and software locations.
1-4 Oracle Database Administrator's Reference
Environment Variables
Table 1-2 Environment Variables Used with Oracle Database
Variable
ADA_PATH
(IBM AIX on POWER Systems
(64-Bit) only)
Definition
Function: Specifies the directory containing the Ada compiler
Syntax:
directory_path
Example:
/usr/lpp/powerada
CLASSPATH
Function: Used with Java applications. The required setting for this variable depends on the Java application. Refer to the product documentation for Java application for more information.
Syntax: Colon-separated list of directories or files:
directory1:directory2:file1:file1
Example: There is no default setting.
CLASSPATH
must include the following directories:
$ORACLE_HOME/jdk/jre/lib:$ORACLE_HOME/jlib
DISPLAY
Function: Used by X-based tools. Specifies the display device used for input and output. Refer to the X Window System documentation for information.
Syntax:
hostname:server[.screen]
where
hostname
is the system name (either IP address or alias),
server
is the sequential code number for the server, and
screen
is the sequential code number for the screen. If you use a single monitor, then use the value
0
for both server and screen (
0.0
).
Note
: If you use a single monitor, then
screen
is optional.
Example:
134.287.222.12:0.0
bambi:0
HOME
LANG
or
LC_ALL
LD_OPTIONS
LPDEST
(Oracle
Solaris only)
Function: The home directory of the user.
Syntax:
directory_path
Example:
/home/oracle
Function: Specifies the language and character set used by the operating system for messages and other output. Oracle tools that are programmed in Java, such as Oracle Universal Installer and Oracle
Database Configuration Assistant, may also use this variable to determine the language of their user interface. Refer to the operating system documentation for more information.
Function: Specifies the default linker options. Refer to the ld
man page for more information about this environment variable.
Function: Specifies the name of the default printer.
Syntax:
string
Example: docprinter
Administering Oracle Database 1-5
Environment Variables
Table 1-2 (Cont.) Environment Variables Used with Oracle Database
Variable Definition
LD_LIBRARY_PATH
Function: Environment variable to specify the path used to search for libraries on UNIX and Linux. The environment variable may have a different name on some operating systems, such as
LIBPATH
on IBM
AIX on POWER Systems (64-Bit), and
SHLIB_PATH
on HP-UX.
Syntax: Colon-separated list of directories:
directory1:directory2:directory3
Example:
/usr/dt/lib:$ORACLE_HOME/lib
PATH
Function: Used by the shell to locate executable programs; must include the
$ORACLE_HOME/bin
directory.
Syntax: Colon-separated list of directories:
directory1:directory2:directory3
Example:
/bin:/usr/bin:/usr/local/bin:/usr/bin/
X11:$ORACLE_HOME/bin:$HOME/bin:
PRINTER
TEMP
USER
,
TMP
TMPDIR
, and
(when using telnet to connect on
HP-UX Itanium systems)
Function: Specifies the name of the default printer.
Syntax:
string
Example: docprinter
Function: Specifies the default directories for temporary files. If set, then the tools that create temporary files create them in one of these directories.
Syntax:
directory_path
Example:
/u02/oracle/tmp
Function: Specifies the name of the user logging in.
Syntax:
string
Example: oracle
1.2.3 Setting a Common Environment
This section describes how to set a common operating system environment by using the oraenv
or coraenv
scripts, depending on the default shell:
• For the Bourne, Bash, or Korn shell, use the oraenv
command.
• For the C shell, use the coraenv
command.
oraenv and coraenv Script Files
The oraenv
and coraenv
scripts are created during installation. These scripts set environment variables based on the contents of the oratab
file and provide:
• A central means of updating all user accounts with database changes
• A mechanism for switching between databases specified in the oratab
file
You may find yourself frequently adding and removing databases from the development system or your users may be switching between several different Oracle
Databases installed on the same system. You can use the oraenv
or coraenv
script to ensure that user accounts are updated and to switch between databases.
1-6 Oracle Database Administrator's Reference
Initialization Parameters
Note:
Do not call the oraenv
or coraenv
script from the Oracle software owner
(typically, oracle
) user's shell startup script. Because these scripts prompt for values, they can prevent the dbstart
script from starting a database automatically when the system starts.
The oraenv
or coraenv
script is usually called from the user's shell startup file (for example,
.profile
or
.login
). It sets the
ORACLE_SID
and
ORACLE_HOME environment variables and includes the
$ORACLE_HOME/bin
directory in the
PATH environment variable setting. When switching between databases, users can run the oraenv
or coraenv
script to set these environment variables.
Note:
To run one of these scripts, use the appropriate command:
• coraenv
script:
% source /usr/local/bin/coraenv
• oraenv
script:
$ . /usr/local/bin/oraenv
Local bin Directory
The directory that contains the oraenv
, coraenv
, and dbhome
scripts is called the local bin
directory. All database users must have read access to this directory. Include the path of the local bin directory
PATH
environment variable setting for the users.
When you run the root.sh
script after installation, the script prompts you for the path of the local bin
directory and automatically copies the oraenv
, coraenv
, and dbhome
scripts to the directory that you specify. The default local bin
directory is
/usr/local/bin
. If you do not run the root.sh
script, then you can manually copy the oraenv
or coraenv
and dbhome
scripts from the
$ORACLE_HOME/bin directory to the local bin
directory.
1.2.4 Setting the System Time Zone
The
TZ
environment variable sets the time zone. It enables you to adjust the clock for daylight saving time changes or different time zones.
See Also:
•
(page 1-2)" in "
•
Oracle Database Globalization Support Guide
and Oracle Database
Administrator's Guide
for more information about setting the database time zone
1.3 Initialization Parameters
These sections provide information about Oracle Database initialization parameters.
Administering Oracle Database 1-7
Initialization Parameters
Topics:
•
ASM_DISKSTRING Initialization Parameter
(page 1-8)
•
DISK_ASYNCH_IO Initialization Parameter (HP-UX) (page 1-8)
•
PROCESSOR_GROUP_NAME Initialization Parameter
(page 1-9)
•
Managing Diagnostic Data (page 1-9)
1.3.1 ASM_DISKSTRING Initialization Parameter
Note:
Only Automatic Storage Management instances support the
ASM_DISKSTRING
initialization parameter.
The syntax for assigning a value to the
ASM_DISKSTRING
initialization parameter is as follows:
ASM_DISKSTRING = 'path1'[,'path2', . . .]
In this syntax,
pathn
is the path to a raw device. You can use wildcard characters when specifying the path.
(page 1-8) lists the platform-specific default values for the
ASM_DISKSTRING
initialization parameter.
Table 1-3 Default Values of the ASM_DISKSTRING Initialization Parameter
Platform
Oracle Solaris
Linux
IBM AIX on POWER
Systems (64-Bit)
HP-UX
Default Search String
/dev/rdsk/*
/dev/sd*
/dev/rhdisk*
/dev/rdisk*
1.3.2 DISK_ASYNCH_IO Initialization Parameter (HP-UX)
The
DISK_ASYNCH_IO
initialization parameter determines whether the database files reside on raw disks or file systems. Asynchronous I/O is available only with
Automatic Storage Management disk group which uses raw partitions as the storage option for database files. The
DISK_ASYNCH_IO
parameter can be set to
TRUE
or
FALSE
depending on where the files reside. By default, the value is set to
TRUE
.
Note:
The
DISK_ASYNCH_IO
parameter must be set to
FALSE
when the database files reside on file system. This parameter must be set to
TRUE
only when the database files reside on raw partitions.
1-8 Oracle Database Administrator's Reference
Initialization Parameters
1.3.3 PROCESSOR_GROUP_NAME Initialization Parameter
PROCESSOR_GROUP_NAME
specifies the name of the processor group in which an instance is running. This parameter instructs Oracle databases to run only on processors which are a part of the specified operating system processor groups. For
NUMA systems, all System Global Area (SGA) and Program Global Area (PGA) are allocated from the NUMA nodes associated with the CPUs in this processor group.
PROCESSOR_GROUP_NAME
parameter is only supported on Linux x86-64 and Oracle
Solaris 11 SRU 4 and later.
On Linux x86-64, the named subset of CPUs is created through a Linux feature called control groups (cgroups). Cgroups are introduced in Linux kernel version 2.6.24. It is created by specifying a name and a set of CPUs for the group. When a process is mapped to a cgroup, it uses only the CPUs associated with the cgroup.
On Oracle Solaris 11 SRU 4, the named subset of CPUs is created through a feature called resource pools. Each resource pool consists of a name and a set of CPUs. When a process is mapped to a resource pool, it uses the CPUs associated with the resource pool.
Note:
Oracle recommends that the
PROCESSOR_GROUP_NAME
parameter is set only for databases using a dedicated connection broker. The
USE_DEDICATED_BROKER
initialization parameter is used to configure the dedicated connection brokers.
Related Topics:
Oracle Database Reference
Oracle Database Reference
1.3.4 Managing Diagnostic Data
Diagnostic data includes the trace files, dumps, and core files to investigate, track, and resolve problems quickly and effectively.
Related Topics:
Oracle Database Administrator’s Guide
Administering Oracle Database 1-9
Initialization Parameters
1-10 Administrator's Reference
2
Stopping and Starting Oracle Software
This chapter describes how to identify Oracle Database processes, and provides basic information about how to stop and restart them. It also describes how to set up automatic startup and shutdown of the Oracle Database. It contains the following sections:
•
Stopping and Starting Oracle Processes (page 2-1)
•
Automating Shutdown and Startup (page 2-3)
Note:
When using Oracle Restart, you can use Service Control Utility (SRVCTL), a command-line interface, to manage Oracle processes (database instance, listener, Oracle ASM instance). With SRVCTL, you can manage the Oracle
Restart configuration, see the status of processes managed by Oracle Restart, and start or stop processes such as Oracle Database. SRVCTL is enhanced to support Oracle Clusterware, and single instance Oracle databases with Oracle
Restart.
See Also:
Oracle Database Administrator’s Guide
and Oracle Real Application Clusters
Administration and Deployment Guide
for more information about SRVCTL commands.
2.1 Stopping and Starting Oracle Processes
This section describes how to stop and start Oracle processes. It contains the following topics:
•
Stopping and Starting Oracle Database and Oracle Automatic Storage
Management Instances (page 2-1)
•
Stopping and Starting Oracle Restart
(page 2-3)
2.1.1 Stopping and Starting Oracle Database and Oracle Automatic Storage
Management Instances
This section describes how to stop and start Oracle Database and Oracle Automatic
Storage Management instances and contains the following topics:
•
Stopping an Oracle Database or Oracle Automatic Storage Management Instance
(page 2-2)
Stopping and Starting Oracle Software 2-1
Stopping and Starting Oracle Processes
•
Restarting an Oracle Database or Oracle Automatic Storage Management Instance
(page 2-3)
2.1.1.1 Stopping an Oracle Database or Oracle Automatic Storage Management
Instance
Caution:
Do not stop an Oracle Automatic Storage Management instance until you have stopped all Oracle Database instances that use Oracle Automatic Storage
Management instance to manage their storage.
To stop an Oracle Database or Oracle Automatic Storage Management instance:
1.
Run the following commands to identify the SID and Oracle home directory for the instance that must be shut down:
On Oracle Solaris:
$ cat /var/opt/oracle/oratab
On other operating systems:
$ cat /etc/oratab
The oratab
file contains lines similar to the following, which identify the
SID
and corresponding Oracle home directory for each database or Oracle Automatic
Storage Management instance on the system:
$ORACLE_SID:$ORACLE_HOME:<N/Y>
Note:
Oracle recommends that you use the plus sign (+) as the first character in the
SID
of Oracle Automatic Storage Management instances.
2.
Run the oraenv
or coraenv
script, depending on the default shell, to set the environment variables for the instance that must be shut down:
• Bourne, Bash, or Korn shell:
$ . /usr/local/bin/oraenv
• C shell:
% source /usr/local/bin/coraenv
When prompted, specify the
SID
for the instance.
3.
Run the following commands to shut down the instance:
$ sqlplus
SQL> CONNECT SYS AS SYSDBA
Enter password: sys_password
SQL> SHUTDOWN NORMAL
After the instance shuts down, you can quit SQL*Plus.
2-2 Oracle Database Administrator's Reference
About Automating Database Shutdown and Startup
2.1.1.2 Restarting an Oracle Database or Oracle Automatic Storage Management
Instance
Caution:
If the database instance uses Oracle Automatic Storage Management for storage management, then you must start the Oracle Automatic Storage
Management instance before you start the database instance.
To restart an Oracle Database or Oracle Automatic Storage Management instance:
1.
Repeat steps 1 (page 2-2) and 2 (page 2-2), if required, to set the
ORACLE_SID
and
ORACLE_HOME
environment variables to identify the SID and Oracle home directory for the instance you want to start.
2.
Run the following commands to start the instance:
$ sqlplus
SQL> CONNECT SYS AS SYSDBA
Enter password: sys_password
SQL> STARTUP
After the instance starts, you can exit from SQL*Plus.
2.1.2 Stopping and Starting Oracle Restart
To stop or start Oracle Restart, run the following command:
• Start: This option is used to start Oracle Restart
Syntax and Options: crsctl start has
• Stop: This option is used to stop Oracle Restart
Syntax and Options: crsctl stop has
See Also:
Oracle Database Administrator's Guide
for more information about the srvctl commands
2.2 About Automating Database Shutdown and Startup
Oracle recommends that you configure the system to automatically start Oracle
Database when the system starts, and to automatically shut it down when the system shuts down. Automating database startup and shutdown guards against incorrect database shutdown.
To automate database startup and shutdown, use the dbstart
and dbshut
scripts, which are located in the
$ORACLE_HOME/bin
directory. The scripts refer to the same entries in the oratab
file, which are applied on the same set of databases. You cannot, for example, have the dbstart
script automatically start sid1
, sid2
, and sid3
, and
Stopping and Starting Oracle Software 2-3
About Automating Database Shutdown and Startup have the dbshut
script shut down only sid1
. However, you can specify that the dbshut
script shuts down a set of databases while the dbstart
script is not used at all. To do this, include a dbshut
entry in the system shutdown file, but do not include the dbstart
entry in the system startup files.
See Also:
The init
command in the operating system documentation for more information about system startup and shutdown procedures
2.2.1 Automating Database Startup and Shutdown
To automate database startup and shutdown by using the dbstart
and dbshut scripts:
1.
Log in as the root
user.
2.
Edit the oratab
file for the platform.
To open the file, use one of the following commands:
• On Oracle Solaris:
# vi /var/opt/oracle/oratab
• On IBM AIX on POWER Systems (64-Bit) and Linux:
# vi /etc/oratab
Database entries in the oratab
file are displayed in the following format:
$ORACLE_SID:ORACLE_HOME:<N|Y>
In this example, the values
Y
and
N
specify whether you want the scripts to start or shut down the database, respectively. For each database for which you want to automate shutdown and startup, first determine the instance identifier (SID) for that database, which is identified by the SID in the first field. Then, change the last field for each to
Y
.
You can set dbstart
to autostart a single-instance database which uses an
Automatic Storage Management installation auto-started by Oracle Clusterware.
This is the default behavior for an Automatic Storage Management cluster. To do this, you must change the oratab
entry of the database and the Automatic Storage
Management installation to use a third field with the value
W
and
N
, respectively.
These values specify that dbstart
auto-starts the database only after the
Automatic Storage Management instance is started.
Note:
If you add new database instances to the system and automate the startup for them, then you must edit the entries for those instances in the oratab
file.
3.
Change directory to one of the following, depending on the operating system:
2-4 Oracle Database Administrator's Reference
About Automating Database Shutdown and Startup
Platform
Linux and Oracle Solaris
IBM AIX on POWER
Systems (64-Bit)
Initialization File Directory
/etc/init.d
/etc
4.
Create a file called dbora
, and copy the following lines into this file:
Note:
Change the value of the
ORACLE_HOME
environment variable to specify the
Oracle home directory for the installation. Change the value of the
ORACLE environment variable to the user name of the owner of the database installed in the Oracle home directory (typically, oracle
).
#! /bin/sh
# description: Oracle auto start-stop script.
#
# Set ORACLE_HOME to be equivalent to the $ORACLE_HOME
# from which you wish to execute dbstart and dbshut;
#
# Set ORA_OWNER to the user id of the owner of the
# Oracle database in ORACLE_HOME.
ORA_HOME=<Type your ORACLE_HOME in full path here>
ORA_OWNER=<Type your Oracle account name here> case "$1" in
'start')
# Start the Oracle databases:
# The following command assumes that the oracle login
# will not prompt the user for any values
# Remove "&" if you don't want startup as a background process.
su - $ORA_OWNER -c "$ORA_HOME/bin/dbstart $ORA_HOME" &
touch /var/lock/subsys/dbora
;;
'stop')
# Stop the Oracle databases:
# The following command assumes that the oracle login
# will not prompt the user for any values
su - $ORA_OWNER -c "$ORA_HOME/bin/dbshut $ORA_HOME" &
rm -f /var/lock/subsys/dbora
;; esac
Note:
This script can only stop Oracle Net listener for which a password has not been set. In addition, if the listener name is not the default name,
LISTENER
, then you must specify the listener name in the stop
and start
commands:
$ORACLE_HOME/bin/lsnrctl {start|stop} listener_name
Stopping and Starting Oracle Software 2-5
About Automating Database Shutdown and Startup
5.
Change the group of the dbora
file to the OSDBA group (typically dba
), and set the permissions to 750:
# chgrp dba dbora
# chmod 750 dbora
6.
Create symbolic links to the dbora
script in the appropriate run-level script directories, as follows:
Platform Symbolic Links Commands
Oracle Solaris
# ln -s /etc/init.d/dbora /etc/rc0.d/K01dbora
# ln -s /etc/init.d/dbora /etc/rc3.d/S99dbora
Linux
# ln -s /etc/init.d/dbora /etc/rc.d/rc0.d/K01dbora
# ln -s /etc/init.d/dbora /etc/rc.d/rc3.d/S99dbora
# ln -s /etc/init.d/dbora /etc/rc.d/rc5.d/S99dbora
IBM AIX on
POWER
Systems (64-
Bit)
# ln -s /etc/dbora /etc/rc.d/rc2.d/S99dbora
# ln -s /etc/dbora /etc/rc.d/rc0.d/K01dbora
2-6 Oracle Database Administrator's Reference
3
Configuring Oracle Database
This chapter describes how to configure Oracle Database for Oracle products. It contains the following sections:
•
Using Configuration Assistants
(page 3-1)
•
(page 3-2)
3.1 Using Configuration Assistants
Oracle Database software is supplied with configuration assistants that you can use to perform various database administration operations.
This section contains the following topics:
•
Using Oracle Net Configuration Assistant
(page 3-1)
•
Using Oracle Database Upgrade Assistant (page 3-1)
•
Using Oracle Database Configuration Assistant (page 3-2)
3.1.1 Using Oracle Net Configuration Assistant
Oracle Net Configuration Assistant enables you to configure basic network components during installation, including listener names and protocol addresses, naming methods, net service names in tnsnames.ora
file, and directory server usage.
After installation is complete, you can use Oracle Net Configuration Assistant to create a more detailed configuration by entering the following command:
$ $ORACLE_HOME/bin/netca
Note:
When you use DBCA to create a database, it automatically updates the network configuration files to include information for the new database.
3.1.2 Using Oracle Database Upgrade Assistant
Oracle Database Upgrade Assistant (DBUA) interactively guides you through a database upgrade and configures the database for the new release. DBUA automates the upgrade by performing all tasks normally performed manually. DBUA makes recommendations for configuration options such as tablespaces and the online redo log.
To start DBUA, run the following command:
Configuring Oracle Database 3-1
Relinking Executables
$ $ORACLE_HOME/bin/dbua
For information about the command-line options available with DBUA, use the
-help or
-h
command-line arguments. For example:
$ $ORACLE_HOME/bin/dbua -help
Related Topics:
Oracle Database Upgrade Guide
3.1.3 Using Oracle Database Configuration Assistant
Oracle Database Configuration Assistant (DBCA) is a graphical user interface that assists you in creating and configuring a default or customized database. It also enables you to configure an existing database to add Oracle Database features, and create Oracle Automatic Storage Management disk groups. DBCA also generates a set of shell and SQL scripts that you can inspect, modify, and run at a later time to create a database.
To start DBCA, run the following command:
$ $ORACLE_HOME/bin/dbca
For information about the command-line options available with DBCA, use the
-help or
-h
command-line arguments. For example:
$ $ORACLE_HOME/bin/dbca -help
3.2 Relinking Executables
You can relink the product executables manually by using the relink
shell script located in the
$ORACLE_HOME/bin
directory. You must relink the product executables every time you apply an operating system patch or after an operating system upgrade.
Note:
Before relinking executables, you must shut down all the relinking executables which run in the Oracle home directory. In addition, shut down applications linked with Oracle shared libraries. The relink
script takes all
and as_installed
as arguments. If you do not specify any argument, then the all
argument is considered.
Depending on the products that have been installed in the Oracle home directory, the relink
script relinks all Oracle product executables.
See Also:
Oracle Database Installation Guide for Linux
for more information about how to use the relink script with Automatic Storage Manager
To relink the product executables, run the following command:
$ relink
3-2 Oracle Database Administrator's Reference
4
Administering SQL*Plus
This chapter describes how to administer SQL*Plus. It contains the following sections:
•
Administering Command-Line SQL*Plus
(page 4-1)
•
Using Command-Line SQL*Plus (page 4-3)
•
(page 4-5)
Related Topics:
SQL*Plus User's Guide and Reference
4.1 Administering Command-Line SQL*Plus
This section describes how to administer command-line SQL*Plus. In the examples,
SQL*Plus replaces the question mark (?) with the value of the
ORACLE_HOME environment variable.
•
•
Using the PRODUCT_USER_PROFILE Table
(page 4-2)
•
Using Oracle Database Sample Schemas
(page 4-2)
•
Installing and Removing SQL*Plus Command-Line Help
(page 4-2)
4.1.1 Using Setup Files
When you start SQL*Plus, it runs the glogin.sql
site profile setup file and then runs the login.sql
user profile setup file.
Using the Site Profile File
The global site profile file is
$ORACLE_HOME/sqlplus/admin/glogin.sql
. If a site profile already exists at this location, then it is overwritten when you install SQL*Plus.
If SQL*Plus is removed, then the site profile file is also removed.
Using the User Profile File
The user profile file is login.sql
. SQL*Plus looks for this file in the current directory, and then in the directories specified by the
SQLPATH
environment variable.
The value of this environment variable is a colon-separated list of directories.
SQL*Plus searches these directories for the login.sql
file in the order that they are listed in the
SQLPATH
environment variable.
The options set in the login.sql
file override those set in the glogin.sql
file.
Administering SQL*Plus 4-1
Administering Command-Line SQL*Plus
See Also:
SQL*Plus User's Guide and Reference
for more information about profile files
4.1.2 Using the PRODUCT_USER_PROFILE Table
Oracle Database provides the PRODUCT_USER_PROFILE table that you can use to disable the specified SQL and SQL*Plus commands. This table is automatically created when you choose an installation type that installs a preconfigured database.
See Also:
Oracle Database Installation Guide
for more information about installation options
To re-create the PRODUCT_USER_PROFILE table, run the
$ORACLE_HOME/ sqlplus/admin/pupbld.sql
script in the SYSTEM schema. For example, run the following commands, where
SYSTEM_PASSWORD
is the password of the SYSTEM user:
$ sqlplus
SQL> CONNECT SYSTEM
Enter password: system_password
SQL> @?/sqlplus/admin/pupbld.sql
You can also re-create the PRODUCT_USER_PROFILE table manually in the SYSTEM schema by using the
$ORACLE_HOME/bin/pupbld
shell script. This script prompts for the SYSTEM password. To run the pupbld
script without interaction, set the
SYSTEM_PASS
environment variable to the SYSTEM user name and password.
4.1.3 Using Oracle Database Sample Schemas
When you install Oracle Database or use Oracle Database Configuration Assistant to create a database, you can choose to install Oracle Database Sample Schemas.
Related Topics:
Oracle Database Sample Schemas
4.1.4 Installing and Removing SQL*Plus Command-Line Help
This section describes how to install and remove the SQL*Plus command-line Help.
•
Installing SQL*Plus Command-Line Help (page 4-2)
•
Removing SQL*Plus Command-Line Help
(page 4-3)
Related Topics:
SQL*Plus User's Guide and Reference
4.1.4.1 Installing SQL*Plus Command-Line Help
There are three ways to install the SQL*Plus command-line Help:
• Complete an installation that installs a preconfigured database.
4-2 Oracle Database Administrator's Reference
Using Command-Line SQL*Plus
When you install a preconfigured database as part of an installation, SQL*Plus automatically installs the SQL*Plus command-line Help in the SYSTEM schema.
• Install the command-line Help manually in the SYSTEM schema by using the
$ORACLE_HOME/bin/helpins
shell script.
The helpins
script prompts for the SYSTEM password. To run this script without interaction, set the
SYSTEM_PASS
environment variable to the SYSTEM user name and password. For example:
– Bourne, Bash, or Korn shell:
$ SYSTEM_PASS=SYSTEM/system_password; export SYSTEM_PASS
– C shell:
% setenv SYSTEM_PASS SYSTEM/system_password
• Install the command-line Help manually in the SYSTEM schema by using the
$ORACLE_HOME/sqlplus/admin/help/helpbld.sql
script.
For example, run the following commands, where
system_password
is the password of the SYSTEM user:
$ sqlplus
SQL> CONNECT SYSTEM
Enter password: system_password
SQL> @?/sqlplus/admin/help/helpbld.sql ?/sqlplus/admin/help helpus.sql
Note:
Both the helpins
shell script and the helpbld.sql
script drop existing command-line Help tables before creating new tables.
4.1.4.2 Removing SQL*Plus Command-Line Help
To manually drop the SQL*Plus command-line Help tables from the SYSTEM schema, run the
$ORACLE_HOME/sqlplus/admin/help/helpdrop.sql
script. To do this, run the following commands, where
system_password
is the password of the
SYSTEM user:
$ sqlplus
SQL> CONNECT SYSTEM
Enter password: system_password
SQL> @?/sqlplus/admin/help/helpdrop.sql
4.2 Using Command-Line SQL*Plus
This section describes how to use command-line SQL*Plus. It contains the following topics:
•
Using a System Editor from SQL*Plus
(page 4-4)
•
Running Operating System Commands from SQL*Plus
(page 4-4)
•
(page 4-5)
•
Using the SPOOL Command (page 4-5)
Administering SQL*Plus 4-3
Using Command-Line SQL*Plus
4.2.1 Using a System Editor from SQL*Plus
If you run an
ED
or
EDIT
command at the SQL*Plus prompt, then the system starts an operating system editor, such as ed
, emacs
, ned
, or vi
. However, the
PATH environment variable must include the directory where the editor executable is located.
The
HISTORY
command enables users to run, edit, or delete previously used
SQL*Plus, SQL, or PL/SQL commands from the history list in the current session. You can enable or disable the history of commands issued in the current SQL*Plus session.
When you start the editor, the current SQL buffer is placed in the editor. When you exit the editor, the changed SQL buffer is returned to SQL*Plus.
You can specify which editor should start by defining the SQL*Plus
_EDITOR
variable.
You can define this variable in the glogin.sql
site profile or the login.sql
user profile. Alternatively, you can define it during the SQL*Plus session. For example, to set the default editor to vi
, run the following command:
SQL> DEFINE _EDITOR=vi
If you do not set the
_EDITOR
variable, then the value of either the
EDITOR
or the
VISUAL
environment variable is used. If both environment variables are set, then the value of the
EDITOR
variable is used. If
_EDITOR
,
EDITOR
, and
VISUAL
are not specified, then the default editor is vi
. The defined editor is used in the edit option of the
HISTORY
command. Consider the following SQL statements:
SQL> hist
1 select * from dual;
2 desc dual
To open the first entry in the above SQL statements in the vi
editor, use the following command:
SQL> hist 1 edit
When you start the editor, SQL*Plus uses the afiedt.buf
temporary file to pass text to the editor. You can use the
SET EDITFILE
command to specify a different file name. For example:
SQL> SET EDITFILE /tmp/myfile.sql
SQL*Plus does not delete the temporary file.
4.2.2 Running Operating System Commands from SQL*Plus
Using the HOST command or an exclamation point (!) as the first character after the
SQL*Plus prompt causes subsequent characters to be passed to a subshell. The
SHELL environment variable sets the shell used to run operating system commands. The default shell is the Bourne shell. If the shell cannot be run, then SQL*Plus displays an error message.
To return to SQL*Plus, run the exit
command or press Ctrl+D.
For example, to run a single command, use the following command syntax:
SQL> ! command
In this example,
command
represents the operating system command that you want to run.
4-4 Oracle Database Administrator's Reference
SQL*Plus Restrictions
To run multiple operating system commands from SQL*Plus, run the HOST or !
command. Press Enter to return to the operating system prompt.
4.2.3 Interrupting SQL*Plus
While running SQL*Plus, you can stop the scrolling record display and terminate a
SQL statement by pressing Ctrl+C.
4.2.4 Using the SPOOL Command
The default file name extension of files generated by the SPOOL command is
.lst
. To change this extension, specify a spool file containing a period (.). For example:
SQL> SPOOL query.txt
4.3 SQL*Plus Restrictions
This section describes the following SQL*Plus restrictions:
•
•
•
Hiding the Password (page 4-5)
4.3.1 Resizing Windows
The default values for the SQL*Plus
LINESIZE
and
PAGESIZE
system variables do not automatically adjust for the window size. If the window size is changed, then you must set the
LINESIZE
and
PAGESIZE
system variables.
4.3.2 Return Codes
Operating system return codes use only one byte, which is not enough space to return an Oracle error code. The range for a return code is 0 to 255.
4.3.3 Hiding the Password
If you pass the password on the command line or set the
SYSTEM_PASS
environment variable to the user name and password of the SYSTEM user, then the output of the ps command may display this information. To prevent unauthorized access, enter the
SYSTEM
password only when prompted by SQL*Plus.
To automatically run a script, consider using an authentication method that does not require you to store a password. For example, externally authenticated logins to
Oracle Database. If you have a low-security environment, then you must consider using the operating system pipes in script files to pass a password to SQL*Plus. For example:
$ echo system_password | sqlplus SYSTEM @MYSCRIPT
Alternatively, run the following commands:
$ sqlplus <<EOF
SYSTEM/system_password
SELECT ...
EXIT
EOF
Administering SQL*Plus 4-5
SQL*Plus Restrictions
In the preceding examples,
system_password
is the password of the SYSTEM user.
4-6 Oracle Database Administrator's Reference
5
Configuring Oracle Net Services
This chapter describes how to configure Oracle Net Services. It contains the following sections:
•
Locating Oracle Net Services Configuration Files
(page 5-1)
•
(page 5-2)
•
(page 5-2)
•
Setting Up the Listener for TCP/IP or TCP/IP with Secure Sockets Layer
(page 5-4)
Related Topics:
Oracle Database Net Services Administrator's Guide
5.1 Locating Oracle Net Services Configuration Files
Oracle Net Services configuration files are typically, but not always, located in the
$ORACLE_HOME/network/admin
directory. Depending on the type of file, Oracle
Net uses a different search order to locate the file.
The search order for the sqlnet.ora
and ldap.ora
files is as follows:
1.
The directory specified by the
TNS_ADMIN
environment variable, if this environment variable is set
2.
The
$ORACLE_HOME/network/admin
directory
The search order for the cman.ora
, listener.ora
, and tnsnames.ora
files is as follows:
1.
The directory specified by the
TNS_ADMIN
environment variable, if this environment variable is set
2.
One of the following directories:
• On Oracle Solaris:
/var/opt/oracle
• On other platforms:
/etc
3.
The
$ORACLE_HOME/network/admin
directory
For some system-level configuration files, users may have a corresponding user-level configuration file stored in their home directory. The settings in the user-level file
Configuring Oracle Net Services 5-1
Using Adapters Utility override the settings in the system-level file. The following table lists the system-level configuration files and the corresponding user-level configuration files:
System-Level Configuration File
sqlnet.ora
tnsnames.ora
User-Level Configuration File
$HOME/.sqlnet.ora
$HOME/.tnsnames.ora
Example 5-1 Sample Configuration Files
The
$ORACLE_HOME/network/admin/samples
directory contains samples of the cman.ora
, listener.ora
, sqlnet.ora
, and tnsnames.ora
configuration files.
Note:
The cman.ora
file is installed only if you select Connection Manager as part of a custom option during a client custom installation.
5.2 Using Adapters Utility
The adapters
utility displays the transport protocols, naming methods, and Oracle
Advanced Security options that Oracle Database supports on the system.
See Also:
Oracle Database Net Services Administrator's Guide
for more information about the adapters
utility
5.3 Using Oracle Protocol Support
Oracle protocol support is a component of Oracle Net. It includes the following:
•
IPC Protocol Support (page 5-2)
•
TCP/IP Protocol Support (page 5-3)
•
TCP/IP with Secure Sockets Layer Protocol Support (page 5-3)
Each of the IPC, TCP/IP, and TCP/IP with Secure Sockets Layer protocol support have an address specification that is used in the Oracle Net Services configuration files and in the
DISPATCHER
initialization parameter. The following sections describe the address specifications for each of the protocol supports.
Related Topics:
Oracle Database Net Services Administrator's Guide
5.3.1 IPC Protocol Support
The IPC protocol support can be used only when the client program and Oracle
Database are installed on the same system. This protocol support requires a listener. It is installed and linked to all client tools and the oracle
executable.
5-2 Oracle Database Administrator's Reference
Using Oracle Protocol Support
The IPC protocol support requires an address specification in the following format:
(ADDRESS = (PROTOCOL=IPC)(KEY=key))
The following table describes the parameters used in this address specification:
Parameter
PROTOCOL
KEY
Description
The protocol to be used. The value is IPC. It is not case-sensitive.
Any name that is different from any other name used for an IPC KEY on the same system.
The following is a sample IPC protocol address:
(ADDRESS= (PROTOCOL=IPC)(KEY=EXTPROC))
5.3.2 TCP/IP Protocol Support
TCP/IP is the standard communication protocol used for client/server communication over a network. The TCP/IP protocol support enables communication between client programs and Oracle Database, whether they are installed on the same or different systems. If the TCP/IP protocol is installed on the system, then the
TCP/IP protocol support is installed and linked to all client tools and to the oracle executable.
The TCP/IP protocol support requires an address specification in the following format:
(ADDRESS = (PROTOCOL=TCP)(HOST=hostname)(PORT=port))
The following table describes the parameters used in this address specification:
Parameter
PROTOCOL
HOST
PORT
Description
The protocol support to be used. The value is TCP. It is not casesensitive.
The host name or the host IP address.
The TCP/IP port. Specify the port as either a number or the alias name mapped to the port in the
/etc/services
file. Oracle recommends a value of 1521.
The following is a sample TCP/IP protocol address:
(ADDRESS= (PROTOCOL=TCP)(HOST=MADRID)(PORT=1521))
5.3.3 TCP/IP with Secure Sockets Layer Protocol Support
The TCP/IP with Secure Sockets Layer protocol support enables an Oracle application on a client to communicate with remote Oracle Database instances through TCP/IP and Secure Sockets Layer.
The TCP/IP with Secure Sockets Layer protocol support requires an address specification in the following format:
(ADDRESS = (PROTOCOL=TCPS)(HOST=hostname)(PORT=port))
Configuring Oracle Net Services 5-3
Setting Up the Listener for TCP/IP or TCP/IP with Secure Sockets Layer
The following table describes the parameters used in this address specification:
Parameter
PROTOCOL
HOST
PORT
Description
The protocol to be used. The value is TCPS. It is not case-sensitive.
The host name or the host IP address.
The TCP/IP with Secure Sockets Layer port. Specify the port as either a number or the alias name mapped to the port in the
/etc/ services
file. Oracle recommends a value of 2484.
The following is a sample TCP/IP with Secure Sockets Layer protocol address:
(ADDRESS= (PROTOCOL=TCPS)(HOST=MADRID)(PORT=2484))
5.4 Setting Up the Listener for TCP/IP or TCP/IP with Secure Sockets
Layer
Oracle recommends that you reserve a port for the listener in the
/etc/services
file of each Oracle Net Services node on the network. The default port is 1521. The entry lists the listener name and the port number. For example:
oraclelistener 1521/tcp
In this example,
oraclelistener
is the name of the listener as defined in the listener.ora
file. Reserve multiple ports if you intend to start multiple listeners.
If you intend to use Secure Sockets Layer, then you should define a port for TCP/IP with Secure Sockets Layer in the
/etc/services
file. Oracle recommends a value of
2484. For example:
oraclelistenerssl 2484/tcps
In this example,
oraclelistenerssl
is the name of the listener as defined in the listener.ora
file. Reserve multiple ports if you intend to start multiple listeners.
5-4 Oracle Database Administrator's Reference
6
Using Oracle Precompilers and the Oracle
Call Interface
This chapter describes how to use Oracle precompilers and the Oracle Call Interface
Topics:
•
Overview of Oracle Precompilers
(page 6-1)
•
Bit-Length Support for Client Applications (page 6-5)
•
(page 6-6)
•
(page 6-9)
•
(page 6-13)
•
(page 6-15)
•
(page 6-17)
•
Running Oracle JDBC/OCI Programs with a 64-Bit Driver (page 6-19)
•
•
(page 6-20)
•
(page 6-21)
•
Using Signal Handlers (page 6-21)
•
6.1 Overview of Oracle Precompilers
Oracle precompilers are application development tools that are used to combine SQL statements for an Oracle Database with programs written in a high-level language.
Oracle precompilers are compatible with ANSI SQL and are used to develop and open customized applications that run with Oracle Database or any other ANSI SQL database management system.
This section contains the following topics:
•
Precompiler Configuration Files
(page 6-2)
•
Relinking Precompiler Executables
(page 6-2)
•
Issues Common to All Precompilers
(page 6-3)
•
(page 6-3)
Using Oracle Precompilers and the Oracle Call Interface 6-1
Overview of Oracle Precompilers
•
Client Shared and Static Libraries
(page 6-3)
Note:
ORACLE_HOME
in this section refers to
ORACLE_HOME
that is created while installing Oracle Database Client 12c by using the Administrator Install type.
6.1.1 Precompiler Configuration Files
Configuration files for the Oracle precompilers are located in the
$ORACLE_HOME/ precomp/admin
directory.
The following table lists the names of the configuration files for each precompiler.
Table 6-1 System Configuration Files for Oracle Precompilers
Product
Pro*C/C++
Pro*COBOL
Pro*FORTRAN (IBM AIX on POWER Systems (64-Bit), HP-UX, and Oracle Solaris)
Object Type Translator
SQL*Module for Ada (IBM AIX on POWER Systems (64-Bit))
Configuration File
pcscfg.cfg
pcbcfg.cfg
pccfor.cfg
ottcfg.cfg
pmscfg.cfg
6.1.2 Relinking Precompiler Executables
Use the
$ORACLE_HOME/precomp/lib/ins_precomp.mk
make file to relink all precompiler executables. To manually relink a particular precompiler executable, enter the following command:
$ make -f ins_precomp.mk relink exename = executable_name
This command creates the new executable in the
$ORACLE_HOME/precomp/lib directory, and then moves it to the
$ORACLE_HOME/bin
directory.
In the preceding example, replace
executable
with one of the product executables listed in
(page 6-2).
The following table lists the executables for Oracle Precompilers:
Table 6-2 Executables for Oracle Precompilers
Product
Pro*FORTRAN 32-bit (Oracle Solaris, HP-UX and IBM AIX on
POWER Systems (64-Bit))
Pro*COBOL 32-bit (Oracle Solaris, HP-UX, and IBM AIX on
POWER Systems (64-Bit))
Pro*COBOL (Oracle Solaris, HP-UX, and IBM AIX on POWER
Systems (64-Bit))
Executable
profor procob procob
or rtsora
6-2 Oracle Database Administrator's Reference
Overview of Oracle Precompilers
Table 6-2 (Cont.) Executables for Oracle Precompilers
Product
Pro*C/C++ 32 bit (HP-UX)
Pro*FORTRAN (HP-UX)
SQL*Module for Ada (IBM AIX on POWER Systems (64-Bit))
Executable
proc profor modada
6.1.3 Issues Common to All Precompilers
The following issues are common to all precompilers:
• Uppercase to Lowercase Conversion
In languages other than C, the compiler converts an uppercase function or subprogram name to lowercase. This can cause a
No such user exists
error message. If you receive this error message, then verify that the case of the function or subprogram name in the option file matches the case used in the IAPXTB table.
• Vendor Debugger Programs
Precompilers and vendor-supplied debuggers can be incompatible. Oracle does not guarantee that a program run using a debugger performs the same way when it is run without the debugger.
• Value of
IRECLEN
and
ORECLEN
parameters
The
IRECLEN
and
ORECLEN
parameters do not have maximum values.
6.1.4 Static and Dynamic Linking
You can statically or dynamically link Oracle libraries with precompiler and OCI or
OCCI applications. With static linking, the libraries and objects of the whole application are linked into a single executable program. As a result, application executables can become very large.
With dynamic linking, the executing code is partly stored in the executable program and partly stored in libraries that are linked dynamically by the application at run time. Libraries that are linked at run time are called dynamic or shared libraries. The benefits of dynamic linking are:
• Reduced disk space requirements: Multiple applications or calls to the same application can use the same dynamic libraries.
• Reduced main memory requirements: The same dynamic library image is loaded into the main memory only once, and it can be shared by multiple applications.
6.1.5 Client Shared and Static Libraries
The client shared and static libraries are located in
$ORACLE_HOME/lib.
If you use the Oracle-provided demo_product.mk
file to link an application, then the client shared library is linked by default.
If the shared library path environment variable setting does not include the directory that contains the client shared library, then you may see an error message similar to one of the following lines when starting an executable:
Using Oracle Precompilers and the Oracle Call Interface 6-3
Overview of Oracle Precompilers
Cannot load library libclntsh.a
cannot open shared library: .../libclntsh.sl.10.1
libclntsh.so.10.1: can't open file: errno=2 can't open library: .../libclntsh.dylib.10.1
Cannot map libclntsh.so
To avoid this error, set the shared library path environment variable to specify the appropriate directory. The following table shows sample settings for this environment variable name. If the platform supports both 32-bit and 64-bit applications, then ensure that you specify the correct directory, depending on the application that you want to run.
Platform
Oracle Solaris (32-bit and 64-bit applications) and Linux
IBM AIX on POWER Systems
(32-bit and 64–bit applications)
HP-UX (32-bit applications)
HP-UX (64-bit applications)
Environment Variable Sample Setting
LD_LIBRARY_PATH $ORACLE_HOME/lib
LIBPATH
SHLIB_PATH
LD_LIBRARY_PATH
$ORACLE_HOME/lib
$ORACLE_HOME/lib
$ORACLE_HOME/lib
The client shared library is created automatically during installation. If you must recreate it, then complete the following procedure:
1.
Quit all client applications that use the client shared library, including all Oracle client applications such as SQL*Plus and Oracle Recovery Manager.
2.
Log in as the oracle
user, and run the following command:
$ $ORACLE_HOME/bin/genclntsh
Non-threaded Client Shared Library
Note:
The information in this section applies to HP-UX systems.
On HP-UX, you can use a non-threaded client shared library. However, you cannot use this library with any OCI application that uses or has a dependency on threads.
To use this library for applications that do not use threads, run the following command to build the OCI application for 32 and 64-bit:
$ make -f demo_rdbms.mk build_nopthread EXE=oci02 OBJS=oci02.o
6.1.6 Generating the Client Static Library
To link applications to the client static library, you must generate it first.
The client static library ( libclntst12.a
) is not generated during an Oracle Database installation. To link the applications to the client static library, you must first generate it:
1.
Switch the user to the Oracle installation owner ( oracle
).
6-4 Oracle Database Administrator's Reference
Bit-Length Support for Client Applications
2.
Set the
ORACLE_HOME
environment variable to specify the Oracle home directory used by the Oracle Database installation. For example:
• Bourne, Bash, or Korn shell:
$ ORACLE_HOME=/u01/app/oracle/product/12.2.0/dbhome_1
$ export ORACLE_HOME
• C shell:
% setenv ORACLE_HOME /u01/app/oracle/product/12.2.0/dbhome_1
3.
Enter the following command:
$ $ORACLE_HOME/bin/genclntst
6.2 Bit-Length Support for Client Applications
The client application type (32-bit or 64-bit) is supported on the following platforms:
• Oracle Solaris
• Linux x86-64
• IBM: Linux on System z
• IBM AIX on POWER Systems (64-Bit)
• HP-UX Itanium
The following table lists the 32-bit and 64-bit client shared libraries:
Platform
Oracle Solaris, Linux x86-64, and IBM:
Linux on System z
32-Bit Client Shared Library
$ORACLE_HOME/lib/libclntsh.so
IBM AIX on POWER
Systems (64-Bit)
$ORACLE_HOME/lib/libclntsh.a
$ORACLE_HOME/lib/libclntsh.so
64-Bit Client Shared Library
$ORACLE_HOME/lib/ libclntsh.so
$ORACLE_HOME/lib/ libclntsh.a
$ORACLE_HOME/lib/ libclntsh.so
HP-UX Itanium
$ORACLE_HOME/lib/ libclntsh.sl
$ORACLE_HOME/lib/ libclntsh.sl
To implement a mixed word-size installation:
1.
Run the following command to generate the 32-bit and 64-bit client shared libraries:
2.
$ $ORACLE_HOME/bin/genclntsh
Include the paths of the required 32-bit and 64-bit client shared libraries in one of the following environment variables, depending on the platform:
Using Oracle Precompilers and the Oracle Call Interface 6-5
Pro*C/C++ Precompiler
Platform
Oracle Solaris, Linux x86-64, IBM:
Linux on System z, and HP-UX
Environment Variable
LD_LIBRARY_PATH
IBM AIX on POWER Systems (64-Bit)
LIBPATH
HP-UX (32-bit client applications)
SHLIB_PATH
Building 32-Bit Pro*C and OCI Customer Applications
If the operating system supports both 32-bit and 64-bit Pro*C and Oracle Call Interface
(OCI) customer applications, then you can find more information about building 32-bit
Pro*C and OCI applications in the following files:
For Information About. . .
Refer to the Following Make Files. . .
Building 32-bit Pro*C applications
$ORACLE_HOME/precomp/demo/proc/demo_proc32.mk
Building 32-bit OCI applications
$ORACLE_HOME/rdbms/demo/demo_rdbms32.mk
6.3 Pro*C/C++ Precompiler
Before you use the Pro*C/C++ precompiler, verify that the correct version of the operating system compiler is properly installed.
See Also:
•
Oracle Database Installation Guide
for information about supported compiler versions
•
Pro*C/C++ Programmer's Guide
for information about the Pro*C/C++ precompiler and interface features
This section contains the following topics:
•
Pro*C/C++ Demonstration Programs
(page 6-6)
•
Pro*C/C++ User Programs (page 6-7)
6.3.1 Pro*C/C++ Demonstration Programs
Demonstration programs are provided to show the features of the Pro*C/C++ precompiler. There are three types of demonstration programs: C, C++, and Object programs. All demonstration programs are located in the
$ORACLE_HOME/precomp/ demo/proc
directory. By default, all programs are dynamically linked with the client shared library.
To run the demonstration programs, the programs require the demonstration tables created by the
$ORACLE_HOME/sqlplus/demo/demobld.sql
script to exist in the
JONES schema with a password.
6-6 Oracle Database Administrator's Reference
Pro*C/C++ Precompiler
Note:
You must unlock the JONES account and set the password before creating the demonstrations.
Use the demo_proc.mk
make file, which is located in the
$ORACLE_HOME/precomp/ demo/proc/
directory, to create the demonstration programs. For example, to precompile, compile, and link the sample1
demonstration program, run the following command:
$ make -f demo_proc.mk sample1
Note:
On IBM AIX on POWER Systems (64-Bit), to ensure that the demonstration programs compile correctly, include the
-r
option of the make
command in the following examples. For example:
$ make -r -f demo_proc.mk sample1
To create all the C demonstration programs for Pro*C/C++, run the following command:
$ make -f demo_proc.mk samples
To create all the C++ demonstration programs for Pro*C/C++, run the following command:
$ make -f demo_proc.mk cppsamples
To create all the Object demonstration programs for Pro*C/C++, run the following command:
$ make -f demo_proc.mk object_samples
Some demonstration programs require you to run a SQL script, located in the
$ORACLE_HOME/precomp/demo/sql
directory. If you do not run the script, then a message prompting you to run it is displayed.
To build a demonstration program and run the corresponding SQL script, include the make
macro argument
RUNSQL=run
at the command line. For example, to create the sample9
demonstration program and run the required
$ORACLE_HOME/precomp/ demo/sql/sample9.sql
script, run the following command:
$ make -f demo_proc.mk sample9 RUNSQL=run
To create all the Object demonstration programs and run all the required SQL scripts, run the following command:
$ make -f demo_proc.mk object_samples RUNSQL=run
6.3.2 Pro*C/C++ User Programs
You can use the
$ORACLE_HOME/precomp/demo/proc/demo_proc.mk
make file to create user programs. This make file builds either 32-bit or 64-bit user programs.
You can also use the demo_proc32.mk
make file to build 32-bit user programs. The
Using Oracle Precompilers and the Oracle Call Interface 6-7
Pro*C/C++ Precompiler following table shows the make files that you can use to build 32-bit and 64-bit user programs with Pro*C/C++:
Platform
Oracle Solaris, Linux x86-64,
IBM: Linux on System z, IBM
AIX on POWER Systems (64-
Bit), and HP-UX
64-bit Make File
demo_proc.mk
32-Bit Make File
demo_proc32.mk
See Also:
The make file for more information about creating user programs
Note:
On IBM AIX on POWER Systems (64-Bit), to ensure that the programs compile correctly, specify the
-r
option for the make
command used in the following examples.
To create a program by using the demo_proc.mk
make file, run a command similar to the following:
$ make -f demo_proc.mk target OBJS="objfile1 objfile2 ..." EXE=exename
In this example:
•
target
is the make file target that you want to use
•
objfilen
is the object file to link the program
•
exename
is the executable program
For example, to create the program myprog
from the Pro*C/C++ source file myprog.pc
, run one of the following commands, depending on the source and the type of executable that you want to create:
• For C source dynamically linked with the client shared library, run the following command:
$ make -f demo_proc.mk build OBJS=myprog.o EXE=myprog
• For C source statically linked with the client shared library, run the following command:
$ make -f demo_proc.mk build_static OBJS=myprog.o EXE=myprog
• For C++ source dynamically linked with the client shared library, run the following command:
$ make -f demo_proc.mk cppbuild OBJS=myprog.o EXE=myprog
• For C++ source statically linked with the client shared library, run the following command:
$ make -f demo_proc.mk cppbuild_static OBJS=myprog.o EXE=myprog
6-8 Oracle Database Administrator's Reference
Pro*COBOL Precompiler
6.4 Pro*COBOL Precompiler
(page 6-9) shows the naming conventions for the Pro*COBOL precompiler.
Table 6-3 Pro*COBOL Naming Conventions
Item
Executable
Demonstration directory
Make file
Naming Convention
procob procob2 demo_procob.mk
or demo_procob_32.mk
Pro*COBOL supports statically linked, dynamically linked, or dynamically loadable programs. Dynamically linked programs use the client shared library. Dynamically loadable programs use the rtsora
executable located in the
$ORACLE_HOME/bin directory.
This section contains the following topics:
•
Pro*COBOL Environment Variables (page 6-9)
•
Pro*COBOL Oracle Runtime System (page 6-11)
•
Pro*COBOL Demonstration Programs
(page 6-11)
•
Pro*COBOL User Programs (page 6-12)
•
FORMAT Precompiler Option (page 6-13)
6.4.1 Pro*COBOL Environment Variables
This section describes the environment variables required by Pro*COBOL:
•
Micro Focus Server Express COBOL Compiler
(page 6-9)
•
Acucorp ACUCOBOL-GT COBOL Compiler (page 6-10)
6.4.1.1 Micro Focus Server Express COBOL Compiler
To use the Micro Focus Server Express COBOL compiler, you must set the
COBDIR and
PATH
environment variables and the shared library path environment variable.
See Also:
The " Client Shared and Static Libraries (page 6-3)" section for information
about the shared library path environment variable
COBDIR
Set the
COBDIR
environment variable to the directory where the compiler is installed.
For example, if the compiler is installed in the
/opt/lib/cobol
directory, then run the following command:
• Bourne, Bash, or Korn shell:
Using Oracle Precompilers and the Oracle Call Interface 6-9
Pro*COBOL Precompiler
$ COBDIR=/opt/lib/cobol
$ export COBDIR
• C shell:
% setenv COBDIR /opt/lib/cobol
PATH
Set the
PATH
environment variable to include the
$COBDIR/bin
directory:
• Bourne, Bash, or Korn shell:
$ PATH=$COBDIR/bin:$PATH
$ export PATH
• C shell:
% setenv PATH ${COBDIR}/bin:${PATH}
Shared Library Path
Set the
LIBPATH
,
LD_LIBRARY_PATH
, or
SHLIB_PATH
environment variable to the directory where the compiler library is installed. For example, if the platform uses the
LD_LIBRARY_PATH
environment variable and the compiler library is installed in the
$COBDIR/coblib
directory, then run the following command:
• Bourne, Bash, or Korn shell:
$ LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$COBDIR/coblib
$ export LD_LIBRARY_PATH
• C shell:
% setenv LD_LIBRARY_PATH ${LD_LIBRARY_PATH}:$COBDIR/coblib
6.4.1.2 Acucorp ACUCOBOL-GT COBOL Compiler
To use the Acucorp ACUCOBOL-GT COBOL compiler, you must set the
A_TERMCAP
,
A_TERM
,
PATH
, and
LD_LIBRARY_PATH
environment variables. If the
LD_LIBRARY_PATH
environment variable setting does not include the correct directory, then an error message similar to the following is displayed when you compile or run a program: runcbl: error while loading shared libraries: libclntsh.so: cannot open shared object file: No such file or directory
A_TERMCAP and A_TERM
Set the
A_TERMCAP
environment variable to specify the location of the a_termcap
file and set the
A_TERM
environment variable to specify a supported terminal from that file. For example:
• Bourne, Bash, or Korn shell:
$ A_TERMCAP=/opt/COBOL/etc/a_termcap
$ A_TERM=vt100
$ export A_TERMCAP A_TERM
• C shell:
% setenv A_TERMCAP /opt/COBOL/etc/a_termcap
% setenv A_TERM vt100
6-10 Oracle Database Administrator's Reference
Pro*COBOL Precompiler
PATH
Set the
PATH
environment variable to include the
/opt/COBOL/bin
directory:
• Bourne, Bash, or Korn shell:
$ PATH=/opt/COBOL/bin:$PATH
$ export PATH
• C shell:
% setenv PATH opt/COBOL/bin:${PATH}
LD_LIBRARY_PATH
Note:
On IBM AIX on POWER Systems (64-Bit), the
LIBPATH
variable is the
LD_LIBRARY_PATH
variable equivalent. You must use the
LIBPATH
variable on IBM AIX on POWER Systems (64-Bit) instead of the
LD_LIBRARY_PATH variable in the following commands.
Set the
LD_LIBRARY_PATH
environment variable to the directory where the compiler library is installed. For example, if the compiler library is installed in the
/opt/
COBOL/lib
directory, then run the following command:
• Bourne, Bash, or Korn shell:
$ LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/opt/COBOL/lib
$ export LD_LIBRARY_PATH
• C shell:
% setenv LD_LIBRARY_PATH ${LD_LIBRARY_PATH}:/opt/COBOL/lib
6.4.2 Pro*COBOL Oracle Runtime System
Oracle provides its own complete run-time system, called rtsora
, to run dynamically loadable Pro*COBOL programs. Use the rtsora
run-time system instead of the cobrun
run-time system to run dynamically loadable Pro*COBOL programs. If you attempt to run a Pro*COBOL program with cobrun
, then an error message similar to the following is displayed:
$ cobrun sample1.gnt
Load error : file 'SQLADR' error code: 173, pc=0, call=1, seg=0
173 Called program file not found in drive/directory
6.4.3 Pro*COBOL Demonstration Programs
Demonstration programs are provided to show the features of the Pro*COBOL precompiler. The demonstration programs are located in the
$ORACLE_HOME/ precomp/demo/procob2
directory. By default, all programs are dynamically linked with the client shared library.
To run the demonstration programs, the programs require the demonstration tables created by the
$ORACLE_HOME/sqlplus/demo/demobld.sql
script to exist in the
JONES schema with a password.
Using Oracle Precompilers and the Oracle Call Interface 6-11
Pro*COBOL Precompiler
Note:
You must unlock the JONES account and set the password before creating the demonstrations.
Use the following make file to create the demonstration programs:
$ORACLE_HOME/precomp/demo/procob2/demo_procob.mk
To precompile, compile, and link the sample1
demonstration program for
Pro*COBOL, run the following command:
$ make -f demo_procob.mk sample1
To create the Pro*COBOL demonstration programs, run the following command:
$ make -f demo_procob.mk samples
To create and run a dynamically loadable sample1.gnt
program to be used with the rtsora
run-time system, run the following command:
$ make -f demo_procob.mk sample1.gnt
$ rtsora sample1.gnt
Some demonstration programs require you to run a SQL script, which is located in the
$ORACLE_HOME/precomp/demo/sql
directory. If you do not run the script, then a message requesting you to run it is displayed.
To build a demonstration program and run the corresponding SQL script, include the make
macro argument
RUNSQL=run
in the command. For example, to create the sample9
demonstration program and run the required
$ORACLE_HOME/precomp/ demo/sql/sample9.sql
script, run the following command:
$ make -f demo_procob.mk sample9 RUNSQL=run
To create the Pro*COBOL demonstration programs and run all required SQL scripts, run the following command:
$ make -f demo_procob.mk samples RUNSQL=run
6.4.4 Pro*COBOL User Programs
You can use the
$ORACLE_HOME/precomp/demo/procob2/demo_procob.mk
make file to create user programs. This make file builds either 32-bit or 64-bit user programs. You can also use the demo_procob_32.mk
make file to build 32-bit user programs. The following table shows the make files that you can use to build 32-bit and 64-bit user programs with Pro*COBOL:
Platform
Oracle Solaris, Linux x86-64, IBM:
Linux on System z, IBM AIX on
POWER Systems (64-Bit), and HP-
UX
64-bit Make File
demo_procob.mk
32-Bit Make File
demo_procob_32.mk
6-12 Oracle Database Administrator's Reference
Pro*FORTRAN Precompiler
See Also:
The make file for more information about creating user programs
To create a program using the demo_procob.mk
make file, run a command similar to the following:
$ make -f demo_procob.mk target COBS="cobfile1 cobfile2 ..." EXE=exename
In this example:
•
target
is the make file target that you want to use
•
cobfilen
is the COBOL source file for the program
•
exename
is the executable program
For example, to create the program myprog
, run one of the following commands, depending on the source and type of executable that you want to create:
• For COBOL source, dynamically linked with the client shared library, run the following command:
$ make -f demo_procob.mk build COBS=myprog.cob EXE=myprog
• For COBOL source, statically linked, run the following command:
$ make -f demo_procob.mk build_static COBS=myprog.cob EXE=myprog
• For COBOL source, dynamically loadable for use with rtsora
, run the following command:
$ make -f demo_procob.mk myprog.gnt
6.4.5 FORMAT Precompiler Option
The FORMAT precompiler option specifies the format of input lines for COBOL. If you specify the default value
ANSI
, then columns 1 to 6 contain an optional sequence number, column 7 indicates comments or continuation lines, paragraph names begin in columns 8 to 11, and statements begin in columns 12 to 72.
If you specify the value
TERMINAL
, then columns 1 to 6 are dropped, making column
7 the left most column.
6.5 Pro*FORTRAN Precompiler
Before you use the Pro*FORTRAN precompiler, verify that the correct version of the compiler is installed. This section contains the following topics:
•
Pro*FORTRAN Demonstration Programs
(page 6-14)
•
Pro*FORTRAN User Programs (page 6-14)
Using Oracle Precompilers and the Oracle Call Interface 6-13
Pro*FORTRAN Precompiler
See Also:
•
Oracle Database Installation Guide
for information about supported compiler versions
•
Pro*FORTRAN Supplement to the Oracle Precompilers Guide
for information about the Pro*FORTRAN precompiler and interface features
6.5.1 Pro*FORTRAN Demonstration Programs
Demonstration programs are provided to show the features of the Pro*FORTRAN precompiler. All demonstration programs are located in the
$ORACLE_HOME/ precomp/demo/profor
directory. By default, all programs are dynamically linked with the client shared library.
To run the demonstration programs, the demonstration tables created by the
$ORACLE_HOME/sqlplus/demo/demobld.sql
script must exist in the JONES schema with a password.
Note:
You must unlock the JONES account and set the password before creating the demonstrations.
To create the demonstration programs, use the demo_profor.mk
make file, located in the
$ORACLE_HOME/precomp/demo/profor
directory. For example, to precompile, compile, and link the sample1
demonstration program, run the following command:
$ make -f demo_profor.mk sample1
To create the Pro*FORTRAN demonstration programs, run the following command:
$ make -f demo_profor.mk samples
Some demonstration programs require you to run a SQL script that is located in the
$ORACLE_HOME/precomp/demo/sql
directory. If you do not run the script, then a message prompting you to run it is displayed.
To build a demonstration program and run the corresponding SQL script, include the make
macro argument
RUNSQL=run
on the command line. For example, to create the sample11
demonstration program and run the required
$ORACLE_HOME/precomp/ demo/sql/sample11.sql
script, run the following command:
$ make -f demo_profor.mk sample11 RUNSQL=run
To create the Pro*FORTRAN demonstration programs and run all the required SQL scripts, run the following command:
$ make -f demo_profor.mk samples RUNSQL=run
6.5.2 Pro*FORTRAN User Programs
You can use the
$ORACLE_HOME/precomp/demo/profor/demo_profor.mk
make file to create user programs. This make file builds either 32-bit or 64-bit user programs.
You can also use the demo_profor_32.mk
make file to build 32-bit user programs.
6-14 Oracle Database Administrator's Reference
SQL*Module for ADA
The following table shows the make files that you can use to build 32-bit and 64-bit user programs with Pro*FORTRAN:
Platform
Oracle Solaris, IBM AIX on POWER
Systems (64-Bit), and HP-UX
64-bit Make File
demo_profor.mk
32-Bit Make File
demo_profor_32.mk
See Also:
The make file for more information about creating user programs
To create a program using the demo_proc.mk
make file, run a command similar to the following:
$ make -f demo_profor.mk target FORS="forfile1 forfile2 ..." EXE=exename
In this example:
•
target
is the make file target that you want to use
•
forfilen
is the FORTRAN source for the program
•
exename
is the executable program
For example, to create the program myprog
from the Pro*FORTRAN source file myprog.pfo
, run one of the following commands, depending on the type of executable that you want to create:
• For an executable dynamically linked with the client shared library, run the following command:
$ make -f demo_profor.mk build FORS=myprog.f EXE=myprog
• For an executable statically linked with the client shared library, run the following command:
$ make -f demo_profor.mk build_static FORS=myprog.f EXE=myprog
6.6 SQL*Module for ADA
Note:
The information in this section applies to the IBM AIX on POWER Systems
(64-Bit) platform.
Before using SQL*Module for Ada, verify that the correct version of the compiler is installed.
Using Oracle Precompilers and the Oracle Call Interface 6-15
SQL*Module for ADA
See Also:
•
Oracle Database Installation Guide
for information about required compiler versions
•
Oracle SQL*Module for Ada Programmer's Guide
for information about
SQL*Module for Ada
This section contains the following topics:
•
SQL*Module for Ada Demonstration Programs (page 6-16)
•
SQL*Module for Ada User Programs (page 6-17)
6.6.1 SQL*Module for Ada Demonstration Programs
Demonstration programs are provided to show the features of SQL*Module for Ada.
All demonstration programs are located in the
$ORACLE_HOME/precomp/demo/ modada
directory. By default, all programs are dynamically linked with the client shared library.
To run the ch1_drv
demonstration program, the demonstration tables created by the
$ORACLE_HOME/sqlplus/demo/demobld.sql
script must exist in the
JONES schema with a password.
Note:
You must unlock the JONES account and set the password before creating the demonstrations.
The demcalsp
and demohost
demonstration programs require that the sample college database exists in the
MODTEST
schema. You can use the appropriate make command to create the
MODTEST
schema and load the sample college database.
Run the following command to create the SQL*Module for Ada demonstration programs, run the necessary SQL scripts to create the
MODTEST
user, and create the sample college database:
$ make -f demo_modada.mk all RUNSQL=run
To create a single demonstration program ( demohost
) and run the necessary SQL scripts to create the
MODTEST
user, and create the sample college database, run the following command:
$ make -f demo_modada.mk makeuser loaddb demohost RUNSQL=run
To create the SQL*Module for Ada demonstration programs, without re-creating the sample college database, run the following command:
$ make -f demo_modada.mk samples
To create a single demonstration program ( demohost
), without re-creating the sample college database, run the following command:
$ make -f demo_modada.mk demohost
6-16 Oracle Database Administrator's Reference
OCI and OCCI
To run the programs, you must define an Oracle Net connect string or alias named
INST1_ALIAS that is used to connect to the database where the appropriate tables exist.
6.6.2 SQL*Module for Ada User Programs
You can use the
$ORACLE_HOME/precomp/demo/modada/demo_modada.mk
make file to create user programs. To create a user program with the demo_modada.mk
make file, run a command similar to the following:
$ make -f demo_modada.mk ada OBJS="module1 module2 ..." \
EXE=exename MODARGS=SQL_Module_arguments
In this example:
•
modulen
is a compiled Ada object
•
exename
is the executable program
•
SQL_Module_arguments
are the command-line arguments to be passed to the
SQL*Module
See Also:
Oracle SQL*Module for Ada Programmer's Guide
for information about
SQL*Module for Ada
6.7 OCI and OCCI
Before you use the Oracle Call Interface (OCI) or Oracle C++ Call Interface (OCCI), verify that the correct version of C or C++ is installed.
See Also:
•
Oracle Database Installation Guide
for information about supported compiler versions
•
Oracle Call Interface Programmer's Guide
or Oracle C++ Call Interface
Programmer's Guide
for information about OCI and OCCI
This section contains the following topics:
•
OCI and OCCI Demonstration Programs
(page 6-17)
•
OCI and OCCI User Programs (page 6-18)
6.7.1 OCI and OCCI Demonstration Programs
Demonstration programs that show the features of OCI and OCCI are provided with the Oracle Database 12c Examples software. There are two types of demonstration programs: C and C++. All demonstration programs are located in the
$ORACLE_HOME/rdbms/demo
directory. By default, all programs are dynamically linked with the client shared library.
Using Oracle Precompilers and the Oracle Call Interface 6-17
OCI and OCCI
To run the demonstration programs, the programs require the demonstration tables created by the
$ORACLE_HOME/sqlplus/demo/demobld.sql script to exist in the
JONES schema with a password. Some demonstration programs require specific .sql
files to be run, as mentioned in the demonstration source files. OCCI demonstration programs require occidemo.sql to be run.
Note:
You must unlock the JONES account and set the password before creating the demonstrations.
Use the demo_rdbms.mk
make file, which is located in the
$ORACLE_HOME/rdbms/ demo
directory, to create the demonstration programs. For example, to compile and link the cdemo1
demonstration program, run the following command:
$ make -f demo_rdbms.mk cdemo1
To create the C demonstration programs for OCI, run the following command:
$ make -f demo_rdbms.mk demos
To create the C++ demonstration programs for OCCI, run the following command:
$ make -f demo_rdbms.mk occidemos
6.7.2 OCI and OCCI User Programs
You can use the
$ORACLE_HOME/rdbms/demo/demo_rdbms.mk
make file to build user programs. This make file builds either 32-bit or 64-bit user programs. You can also use the demo_rdbms32.mk
to build 32-bit user programs on a 64-bit operating system. The following table shows the make files that you can use to build 32-bit and
64-bit user programs with Pro*FORTRAN:
Platform
Oracle Solaris, Linux x86-64, IBM
AIX on POWER Systems (64-Bit), and HP-UX
64-bit Make File
demo_rdbms.mk
32-Bit Make File
demo_rdbms32.mk
See Also:
The make file for more information about building user programs
6-18 Oracle Database Administrator's Reference
Running Oracle JDBC/OCI Programs with a 64-Bit Driver
6.8 Running Oracle JDBC/OCI Programs with a 64-Bit Driver
Note:
• The information in this section applies to Oracle Solaris, Linux x86-64,
IBM: Linux on System z, IBM AIX on POWER Systems (64-Bit), and HP-
UX platforms.
• You can use the instructions and make files described in this section to create JDBC/OCI user programs that use a 64-bit driver.
To run JDBC/OCI demonstration programs with a 64-bit driver:
1.
Add
$ORACLE_HOME/jdbc/lib/ojdbc5.jar
to the start of the
CLASSPATH environment variable value for each of the following files: jdbc/demo/samples/jdbcoci/Makefile jdbc/demo/samples/generic/Inheritance/Inheritance1/Makefile jdbc/demo/samples/generic/Inheritance/Inheritance2/Makefile jdbc/demo/samples/generic/Inheritance/Inheritance3/Makefile jdbc/demo/samples/generic/JavaObject1/Makefile jdbc/demo/samples/generic/NestedCollection/Makefile
2.
Modify the JAVA and JAVAC variables in the
$ORACLE_HOME/jdbc/demo/ samples/generic/Makefile
file to specify the JDK location and the
-d64
flag, as follows:
JAVA=${ORACLE_HOME}/java/bin/java -d64
JAVAC=${ORACLE_HOME}/java/bin/javac -d64
3.
Set the
LD_LIBRARY_PATH_64
environment variable to include the
$ORACLE_HOME/lib
directory.
Note:
On IBM AIX on POWER Systems (64-Bit), the
LIBPATH
variable is the
LD_LIBRARY_PATH_64
variable equivalent. You must use the
LIBPATH variable on IBM AIX on POWER Systems (64-Bit) instead of the
LD_LIBRARY_PATH_64
variable.
6.9 Custom Make Files
Oracle recommends that you use the demo_product.mk
make files provided with the software to create user programs as described in the product-specific sections of this chapter. If you modify the provided make file or if you choose to use a customwritten make file, then remember that the following restrictions apply:
• Do not modify the order of the Oracle libraries. Oracle libraries are included on the link line more than once so that all the symbols are resolved during linking.
Except for IBM AIX on POWER Systems (64-Bit), the order of the Oracle libraries is essential on all platforms for the following reasons:
Using Oracle Precompilers and the Oracle Call Interface 6-19
Correcting Undefined Symbols
– Oracle libraries are mutually referential. For example, functions in library A call functions in library B, and functions in library B call functions in library
A.
– The HP-UX linkers are one-pass linkers. The IBM AIX on POWER Systems
(64-Bit), Linux, and Oracle Solaris linkers are two-pass linkers.
• Add the library to the beginning or to the end of the link line. Do not place user libraries between the Oracle libraries.
• If you choose to use a make
utility such as nmake
or GNU make
, then you must be aware of how macro and suffix processing differs from the make
utility provided with the operating system. Oracle make files are tested and supported with the make
utility.
• Oracle library names and the contents of Oracle libraries are subject to change between releases. Always use the demo_product.mk
make file that ships with the current release as a guide to determine the required libraries.
6.10 Correcting Undefined Symbols
Oracle provides the symfind
utility to assist you in locating a library or object file where a symbol is defined. When linking a program, undefined symbols are a common error that produce an error message similar to the following:
$ make -f demo_proc.mk sample1
Undefined first referenced
symbol in file sqlcex sample1.o
sqlglm sample1.o
ld: irrecoverable: Symbol referencing errors. No output written to sample1
The error occurs when the linker cannot find a definition for a referenced symbol. If this error message is displayed, then verify that the library or object file containing the definition exists on the link line and that the linker is searching the correct directories for the file.
The following example shows the output from the symfind
utility, which is used to locate the sqlcex
symbol:
$ symfind sqlcex
SymFind - Find Symbol <sqlcex> in <**>.a, .o, .so
------------------------------------------------------
Command: /u01/app/oracle/product/12.2.0/bin/symfind sqlcex
Local Directory: /u01/app/oracle/product/12.2.0
Output File: (none)
Note: I do not traverse symbolic links
Use '-v' option to show any symbolic links
Locating Archive and Object files ...
[11645] | 467572| 44|FUNC |GLOB |0 |8 |sqlcex
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ./lib/libclntsh.sl
[35] | 0| 44|FUNC |GLOB |0 |5 |sqlcex
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ./lib/libsql.a
6-20 Oracle Database Administrator's Reference
Multithreaded Applications
6.11 Multithreaded Applications
The Oracle libraries provided with this release are thread-safe, they support multithreaded applications.
See Also:
Pro*C/C++ Programmer's Guide
for more information on Multithreaded
Applications
6.12 Using Signal Handlers
Oracle Database uses signals for two-task communication. Signals are installed in a user process when the process connects to the database and are removed when it disconnects.
The following table describes the signals that Oracle Database uses for two-task communication.
Table 6-4 Signals for Two-Task Communication
Signal
SIGCLD
SIGCONT
SIGINT
SIGIO
SIGPIPE
SIGTERM
SIGURG
Description
The pipe driver uses SIGCLD, also referred to as SIGCHLD, when an Oracle process terminates. The operating system kernel sends a SIGCLD signal to the user process. The signal handler uses the wait()
routine to determine if a server process died. The Oracle process does not catch SIGCLD; the user process catches it.
The pipe two-task driver uses SIGCONT to send out-of-band breaks from the user process to the Oracle process.
Two-task drivers use SIGINT to detect user interrupt requests. The Oracle process does not catch SIGINT; the user process catches it.
Oracle Net protocols use SIGIO to indicate incoming networking events.
The pipe driver uses SIGPIPE to detect end-of-file on the communications channel. When writing to the pipe, if no reading process exists, then a
SIGPIPE signal is sent to the writing process. Both the Oracle process and the user process catch SIGPIPE. SIGCLD is similar to SIGPIPE, but it applies only to user processes, not to Oracle processes.
The pipe driver uses SIGTERM to signal interrupts from the user to the
Oracle process. This occurs when the user presses the interrupt key, Ctrl+C.
The user process does not catch SIGTERM; the Oracle process catches it.
Oracle Net TCP/IP drivers use SIGURG to send out-of-band breaks from the user process to the Oracle process.
The listed signals affect all precompiler applications. You can install one signal handler for SIGCLD (or SIGCHLD) and SIGPIPE when connected to the Oracle process. If you call the osnsui()
routine to set it up, then you can have multiple signal handles for SIGINT. For SIGINT, use osnsui()
and osncui()
to register and delete signal-catching routines.
Using Oracle Precompilers and the Oracle Call Interface 6-21
Using Signal Handlers
You can also install as many signal handlers as you want for other signals. If you are not connected to the Oracle process, then you can have multiple signal handlers.
Example 6-1 (page 6-22) shows how to set up a signal routine and a catching routine.
Example 6-1 Signal Routine and Catching Routine
/* user side interrupt set */ word osnsui( /*_ word *handlp, void (*astp), char * ctx, _*/)
/*
** osnsui: Operating System dependent Network Set User-side Interrupt. Add an
** interrupt handling procedure astp. Whenever a user interrupt(such as a ^C)
** occurs, call astp with argument ctx. Put in *handlp handle for this
** handler so that it may be cleared with osncui. Note that there may be many
** handlers; each should be cleared using osncui. An error code is returned if
** an error occurs.
*/
/* user side interrupt clear */ word osncui( /*_ word handle _*/ );
/*
** osncui: Operating System dependent Clear User-side Interrupt. Clear the
** specified handler. The argument is the handle obtained from osnsui. An error
** code is returned if an error occurs.
*/
Example 6-2 (page 6-22) shows how to use the
osnsui()
and the osncui() routines in an application program.
Example 6-2 osnsui() and osncui() Routine Template
/*
** User interrupt handler template.
*/ void sig_handler()
{
...
} main(argc, argv) int arc; char **argv;
{
int handle, err;
...
/* Set up the user interrupt handler */
if (err = osnsui(&handle, sig_handler, (char *) 0))
{
/* If the return value is nonzero, then an error has occurred
Take appropriate action for the error. */
...
}
...
/* Clear the interrupt handler */
if (err = osncui(handle))
{
/* If the return value is nonzero, then an error has occurred
Take appropriate action for the error. */
6-22 Oracle Database Administrator's Reference
XA Functionality
...
}
...
}
6.13 XA Functionality
Oracle XA is the Oracle implementation of the X/Open Distributed Transaction
Processing XA interface. The XA standard specifies a bidirectional interface between resource managers that provide access to shared resources within transactions, and between a transaction service that monitors and resolves transactions.
Oracle Call Interface has the XA functionality. When building a TP-monitor XA application, ensure that the TP-monitor libraries (that define the symbols ax_reg
and ax_unreg
) are placed in the link line before the Oracle client shared library. This link restriction is required when using the XA dynamic registration (Oracle XA switch xaoswd
).
Oracle Database XA calls are defined in both the client shared library ( libclntsh.a
, libclntsh.sl
, libclntsh.so
, or libclntsh.dylib
depending on the platform) and the client static library ( libclntst11.a
). These libraries are located in the
$ORACLE_HOME/lib
directory.
Using Oracle Precompilers and the Oracle Call Interface 6-23
XA Functionality
6-24 Administrator's Reference
7
SQL*Loader and PL/SQL Demonstrations
This chapter describes how to build and run the SQL*Loader and PL/SQL demonstration programs available with Oracle Database. It contains the following sections:
•
SQL*Loader Demonstrations (page 7-1)
•
PL/SQL Demonstrations (page 7-1)
•
Calling 32-Bit External Procedures from 64-Bit Oracle Database PL/SQL
(page 7-4)
Note:
To use the demonstrations described in this chapter, you must install Oracle
Database Examples included on the Oracle Database 12c Examples media. You must unlock JONES account and set the password before creating the demonstrations.
7.1 SQL*Loader Demonstrations
Run the ulcase.sh
file to run the SQL*Loader demonstrations. To run an individual demonstration, read the information contained in the file to determine how to run it.
7.2 PL/SQL Demonstrations
PL/SQL includes many demonstration programs. You must build database objects and load sample data before using these programs. To build the objects and load the sample data:
1.
Change directory to the PL/SQL demonstrations directory:
2.
3.
$ cd $ORACLE_HOME/plsql/demo
Start SQL*Plus, and enter the following command:
$ sqlplus
SQL> CONNECT JONES
Enter password: password
Run the following commands to build the objects and load the sample data:
SQL> @exampbld.sql
SQL> @examplod.sql
SQL*Loader and PL/SQL Demonstrations 7-1
PL/SQL Demonstrations
Note:
Build the demonstrations as any Oracle user with sufficient privileges. Run the demonstrations as the same Oracle user.
PL/SQL Kernel Demonstrations
The following PL/SQL kernel demonstrations are available with the software:
• examp1.sql
to examp8.sql
• examp11.sql
to examp14.sql
• sample1.sql
to sample4.sql
• extproc.sql
To compile and run the exampn.sql
or samplen.sql
PL/SQL kernel demonstrations:
1.
Start SQL*Plus, and enter the following command:
2.
$ cd $ORACLE_HOME/plsql/demo
$ sqlplus
SQL> CONNECT JONES
Enter password: password
Run a command similar to the following to run a demonstration, where
demo_name
is the name of the demonstration:
SQL> @demo_name
To run the extproc.sql
demonstration:
1.
If required, add an entry for external procedures to the tnsnames.ora
file, similar to the following:
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS=(PROTOCOL = IPC)( KEY = EXTPROC))
)
(CONNECT_DATA =
(SID = PLSExtProc)
)
)
2.
If required, add an entry for external procedures to the listener.ora
file, similar to the following:
Note:
The value that you specify for SID_NAME in the listener.ora
file must match the value that you specify for SID in the tnsnames.ora
file.
• On Oracle Solaris, Linux, and HP-UX:
SID_LIST_LISTENER =
(SID_LIST =
7-2 Oracle Database Administrator's Reference
PL/SQL Demonstrations
(SID_DESC=
(SID_NAME=PLSExtProc)
(ORACLE_HOME=oracle_home_path)
(ENVS=EXTPROC_DLLS=oracle_home_path/plsql/demo/extproc.so,
LD_LIBRARY_PATH=oracle_home_path/plsql/demo)
(PROGRAM=extproc)
)
)
• On IBM AIX on POWER Systems (64-Bit):
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC=
(SID_NAME=PLSExtProc)
(ORACLE_HOME=oracle_home_path)
(ENVS=EXTPROC_DLLS=oracle_home_path/plsql/demo/extproc.so,
LIBPATH=oracle_home_path/plsql/demo)
(PROGRAM=extproc)
)
)
3.
Change directory to
$ORACLE_HOME/plsql/demo
.
4.
Run the following command to create the extproc.so
shared library, build the required database objects, and load the sample data:
$ make -f demo_plsql.mk extproc.so exampbld examplod
Alternatively, if you have already built the database objects and loaded the sample data, then run the following command:
$ make -f demo_plsql.mk extproc.so
5.
From SQL*Plus, run the following commands:
SQL> CONNECT SYSTEM
Enter password: system_password
SQL> GRANT CREATE LIBRARY TO JONES;
SQL> CONNECT JONES
Enter password: password
SQL> CREATE OR REPLACE LIBRARY demolib IS
2 'oracle_home_path/plsql/demo/extproc.so';
3 /
Note:
CREATE LIBRARY
is a very high privilege. This privilege must be granted only to trusted users.
6.
To start the demonstration, run the following command:
SQL> @extproc
SQL*Loader and PL/SQL Demonstrations 7-3
Calling 32-Bit External Procedures from 64-Bit Oracle Database PL/SQL
Example 7-1 PL/SQL Precompiler Demonstrations
Note:
The make
commands shown in this section build the required database objects and load the sample data in the JONES schema.
The following precompiler demonstrations are available:
• examp9.pc
• examp10.pc
• sample5.pc
• sample6.pc
To build the PL/SQL precompiler demonstrations, set the library path environment variable to include the
$ORACLE_HOME/lib
directory, and run the following commands:
$ cd $ORACLE_HOME/plsql/demo
$ make -f demo_plsql.mk demos
To build a single demonstration, run its name as the argument in the make
command.
For example, to build the examp9
demonstration, run the following command:
$ make -f demo_plsql.mk examp9
To start the examp9
demonstration, run the following command:
$ ./examp9
7.3 Calling 32-Bit External Procedures from 64-Bit Oracle Database
PL/SQL
Note:
This section applies to any 64-Bit Oracle Database.
Starting with Oracle Database 11g Release 2 (11.2), extproc32
is no longer available from 64-bit Oracle database install. Therefore, if you have a requirement to run 32-bit external procedures from 64-bit Oracle database, you must obtain 32-bit extproc
by installing the corresponding 32-bit client software for your platform. Specifically, you must choose custom install within 32-bit client installation, and then select both Oracle
Database Utilities and Oracle listener.
In other words, you need a separate Oracle home (32-bit) to run the 32-bit extproc
.
The executable name is not extproc32
anymore, but simply extproc
.
To enable 32-bit external procedures on 64-bit Oracle database environment, you must configure 32-bit listener for extproc
and specify Oracle home (from the 32-bit client install) for the extproc listener.ora
entry.
7-4 Oracle Database Administrator's Reference
8
Tuning Oracle Database
This chapter describes how to tune Oracle Database. It contains the following sections:
•
(page 8-1)
•
(page 8-1)
•
(page 8-8)
•
Tuning Disk Input-Output (page 8-11)
•
Monitoring Disk Performance (page 8-12)
•
System Global Area (page 8-13)
•
Tuning the Operating System Buffer Cache (page 8-18)
8.1 Importance of Tuning
The intent of this section is to efficiently tune and optimize the performance of Oracle
Database. Frequent tuning enhances system performance and prevents data bottlenecks.
Before tuning the database, you must observe its normal behavior by using the tools
described in the " Operating System Tools
(page 8-1)" section.
8.2 Operating System Tools
Several operating system tools are available to enable you to assess database performance and determine database requirements. In addition to providing statistics for Oracle processes, these tools provide statistics for CPU usage, interrupts, swapping, paging, context switching, and I/O for the entire system.
This section provides information about the following common tools:
•
(page 8-2)
•
•
(page 8-3)
•
swap_ swapinfo_ swapon_ or lsps (page 8-4)
•
Oracle Solaris Tools (page 8-4)
•
(page 8-4)
•
IBM AIX on POWER Systems (64-Bit) Tools
(page 8-5)
•
(page 8-6)
Tuning Oracle Database 8-1
Operating System Tools
See Also:
The operating system documentation and man pages for more information about these tools
8.2.1 vmstat
vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity.
Use the vmstat
command to view process, virtual memory, disk, trap, and CPU activity, depending on the switches that you supply with the command. Run one of the following commands to display a summary of CPU activity six times, at fivesecond intervals:
• On Oracle Solaris and HP-UX:
$ vmstat -S 1 2
• On Linux and IBM AIX on POWER Systems (64-bit):
$ vmstat 5 6
The following is a sample output of this command on Linux: procs memory swap io system cpu r b swpd free buff cache si so bi bo in cs us sy id wa st
0 0 130668 103604 198144 5029000 0 0 1 68 8 6 0 0 100 0 0
0 0 130668 103604 198144 5029000 0 0 0 86 226 352 0 0 100 0 0
0 0 130668 103604 198148 5029000 0 0 0 58 223 357 0 0 100 0 0
0 0 130668 103604 198152 5029004 0 0 0 68 223 358 0 0 100 0 0
0 0 130668 103604 198152 5029004 0 0 0 56 223 357 0 0 100 0 0
0 0 130668 103604 198152 5029004 0 0 0 57 228 362 0 0 100 0 0
The following is a sample output of the
$ vmstat -S 1 2
command on HP-UX: procs memory page faults cpu r b w avm free si so pi po fr de sr in sy cs us sy id
1 0 0 112085 2189167 0 0 3 0 0 0 1 1033 32186 108 1 0 98
1 0 0 112085 2189074 0 0 4 0 0 0 0 1022 508 60 0 0 100
The w
sub column, under the procs
column, shows the number of potential processes that have been swapped out and written to disk. If the value is not zero, then swapping occurs and the system is short of memory.
For HP-UX and Oracle Solaris, the si
and so
columns under the page
column indicate the number of processes swapped-in and swapped-out per second, respectively. Ideally these values should be zero.
For Linux, the si
and so
columns represent amount of memory swapped-in and swapped-out.
The sr
column under the page
column indicates the scan rate. High scan rates are caused by a shortage of available memory.
The pi
and po
columns under the page
column indicate the number of page-ins and page-outs per second, respectively. It is normal for the number of page-ins and pageouts to increase. Some paging always occurs even on systems with sufficient available memory.
8-2 Oracle Database Administrator's Reference
Operating System Tools
See Also:
Refer to the vmstat man page for your platform for information about interpreting the output
8.2.2 sar
Depending on the switches that you supply with the command, use the sar
(system activity reporter) command to display cumulative activity counters in the operating system.
On UNIX systems, the following command displays a summary of the input and output activity every ten seconds:
$ sar -b 10 10
The following example shows the output of this command on a Linux system:
10:28:01 tps rtps wtps bread/s bwrtn/s
10:28:11 17.20 0.00 17.20 0.00 300.80
10:28:21 46.40 0.00 46.40 0.00 467.20
10:28:31 16.40 0.00 16.40 0.00 283.20
10:28:41 15.60 0.00 15.60 0.00 275.20
10:28:51 17.02 0.00 17.02 0.00 254.65
10:29:01 35.80 0.00 35.80 0.00 414.40
10:29:11 15.80 0.00 15.80 0.00 273.60
10:29:21 17.40 0.00 17.40 0.00 262.40
10:29:31 32.20 0.00 32.20 0.00 406.40
10:29:41 20.98 0.00 20.98 0.00 354.85
Average: 23.48 0.00 23.48 0.00 329.28
The sar
output provides a snapshot of system input and output activity at a given point in time. If you specify the interval time with multiple options, then the output can become difficult to read. If you specify an interval time of less than 5, then the sar activity itself can affect the output.
See Also:
The man page for more information about sar
8.2.3 iostat
Use the iostat
command to view terminal and disk activity, depending on the switches that you supply with the command. The output from the iostat
command does not include disk request queues, but it shows which disks are busy. You can use this information to balance the Input-Output loads.
The following command displays terminal and disk activity five times, at five-second intervals:
$ iostat 5 5
The following is sample output of the command on Oracle Solaris: tty blkdev0 sd1 sd2 sd3 cpu
tin tout kps tps serv kps tps serv kps tps serv kps tps serv us sy st id
0 1 0 0 0 0 0 31 0 0 18 3 0 42 0 0 0 99
Tuning Oracle Database 8-3
Operating System Tools
0 16 0 0 0 0 0 0 0 0 0 1 0 14 0 0 0 100
0 16 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 100
0 16 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 100
0 16 0 0 0 0 0 0 2 0 14 12 2 47 0 0 1 98
Use the iostat
command to look for large disk request queues. A request queue shows how long the Input-Output requests on a particular disk device must wait to be serviced. Request queues are caused by a high volume of Input-Output requests to that disk or by Input-Output with long average seek times. Ideally, disk request queues should be at or near zero.
8.2.4 swap, swapinfo, swapon, or lsps
Use the swap
, swapinfo
, swapon
, or lsps
command to report information about swap space usage. A shortage of swap space can stop processes to respond, leading to process failures with
Out of Memory
errors. The following table lists the appropriate command to use for each platform:
Platform
Oracle Solaris
Linux
IBM AIX on POWER
Systems (64-bit)
HP-UX
Command
swap -lh
, swap -sh
, and zfs list swapon -s lsps -a swapinfo -m
The following example shows sample output from the swap -l
command on Oracle
Solaris: swapfile dev swaplo blocks free
/dev/zvol/dsk/rpool/swap 274,1 8 2097144 2097144
8.2.5 Oracle Solaris Tools
On Oracle Solaris systems, use the mpstat
command to view statistics for each processor in a multiprocessor system. Each row of the table represents the activity of one processor. The first row summarizes all activity since the last system restart. Each subsequent row summarizes activity for the preceding interval. All values are events per second unless otherwise noted. The arguments are for time intervals between statistics and number of iterations.
The following example shows sample output from the mpstat
command:
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys st idl
0 0 0 1 71 21 23 0 0 0 0 55 0 0 0 99
2 0 0 1 71 21 22 0 0 0 0 54 0 0 0 99
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys st idl
0 0 0 0 61 16 25 0 0 0 0 57 0 0 0 100
2 1 0 0 72 16 24 0 0 0 0 59 0 0 0 100
8.2.6 Linux Tools
On Linux systems, use the top
, free
, and cat /proc/meminfo
commands to view information about swap space, memory, and buffer usage.
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Operating System Tools
8.2.7 IBM AIX on POWER Systems (64-Bit) Tools
The following sections describe tools available on IBM AIX on POWER Systems (64bit):
•
(page 8-5)
•
(page 8-5)
•
System Management Interface Tool (page 8-6)
See Also:
The IBM AIX on POWER Systems (64-bit) operating system documentation and man pages for more information about these tools
8.2.7.1 Base Operation System Tools
The IBM AIX on POWER Systems (64-bit) Base Operation System contains performance tools that are historically part of UNIX systems or are required to manage the implementation-specific features of IBM AIX on POWER Systems (64-bit). The following table lists the most important Base Operation System tools.
Tool
lsattr lslv netstat nfsstat nice no ps reorgvg time trace vmo
Function
Displays the attributes of devices
Displays information about a logical volume or the logical volume allocations of a physical volume
Displays the contents of network-related data structures
Displays statistics about Network File System and Remote Procedure Call activity
Changes the initial priority of a process
Displays or sets network options
Displays the status of one or more processes
Reorganizes the physical-partition allocation within a volume group
Displays the elapsed execution, user CPU processing, and system CPU processing time
Records and reports selected system events
Manages Virtual Memory Manager tunable parameters
8.2.7.2 Performance Toolbox
The IBM AIX on POWER Systems (64-bit) Performance Toolbox contains tools for monitoring and tuning system activity locally and remotely. The Performance Tool
Box consists of two main components, the Performance Tool Box Manager and the
Performance Tool Box Agent. The Performance Tool Box Manager collects and displays data from various systems in the configuration by using the xmperf
utility.
Tuning Oracle Database 8-5
Operating System Tools
The Performance Tool Box Agent collects and transmits data to the Performance Tool
Box Manager by using the xmserd
daemon. The Performance Tool Box Agent is also available as a separate product called Performance Aide for IBM AIX on POWER
Systems (64-bit).
Both Performance Tool Box and Performance Aide include the monitoring and tuning tools listed in the following table:
Tool
fdpr filemon fileplace lockstat lvedit netpmon rmss svmon syscalls tprof
BigFoot stem
Description
Optimizes an executable program for a particular workload
Uses the trace facility to monitor and report the activity of the file system
Displays the placement of blocks of a file within logical or physical volumes
Displays statistics about contention for kernel locks
Facilitates interactive placement of logical volumes within a volume group
Uses the trace facility to report on network Input-Output and networkrelated CPU usage
Simulates systems with various memory sizes for performance testing
Captures and analyzes information about virtual-memory usage
Records and counts system calls
Uses the trace
facility to report CPU usage at module and source-codestatement levels
Reports the memory access patterns of processes
Permits subroutine-level entry and exit instrumentation of existing executables
See Also:
•
Performance Toolbox Version 2 and 3 Guide and Reference
for information about these tools
•
AIX 5L Performance Management Guide
for information about the syntax of some of these tools
8.2.7.3 System Management Interface Tool
The IBM AIX on POWER Systems (64-bit) System Management Interface Tool (SMIT) provides a menu-driven interface to various system administrative and performance tools. By using SMIT, you can navigate through large numbers of tools and focus on the jobs that you want to perform.
8.2.8 HP-UX Tools
The following performance analysis tools are available on HP-UX systems:
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Operating System Tools
• GlancePlus/UX
This HP-UX utility is an online diagnostic tool that measures the activities of the system. GlancePlus displays information about how system resources are used. It displays dynamic information about the system Input-Output, CPU, and memory usage on a series of screens. You can use the utility to monitor how individual processes are using resources.
• HP Programmer's Analysis Kit
HP Programmer's Analysis Kit consists of the following tools:
– Puma
This tool collects performance statistics during a program run. It provides several graphical displays for viewing and analyzing the collected statistics.
– Thread Trace Visualizer
This tool displays trace files produced by the instrumented thread library, libpthread_tr.sl
, in a graphical format. It enables you to view how threads are interacting and to find where threads are blocked waiting for resources.
HP Programmer's Analysis Kit is bundled with the HP Fortran 77, HP Fortran
90, HP C, HP C++, HP ANSI C++, and HP Pascal compilers.
The following table lists the performance tuning tools that you can use for additional performance tuning on HP-UX:
Tool
caliper
(Itanium only) gprof monitor netfmt netstat nfsstat nettl prof profil top
Description
Collects run-time application data for system analysis tasks such as cache misses, translation look-aside buffer or instruction cycles, along with fast dynamic instrumentation. It is a dynamic performance measurement tool for C, C++, Fortran, and assembly applications
Creates an execution profile for programs
Monitors the program counter and calls to certain functions
Monitors the network
Reports statistics on network performance
Displays statistics about Network File System and Remote
Procedure Call activity
Captures network events or packets by logging and tracing
Creates an execution profile of C programs and displays performance statistics for the program, showing where the program is spending most of its execution time
Copies program counter information into a buffer
Displays the top processes on the system and periodically updates the information
Tuning Oracle Database 8-7
Tuning Memory Management
8.3 Tuning Memory Management
Start the memory tuning process by measuring paging and swapping space to determine how much memory is available. After you determine the system memory usage, tune the Oracle buffer cache.
The Oracle buffer manager ensures that the most frequently accessed data is cached longer. If you monitor the buffer manager and tune the buffer cache, then you can significantly improve Oracle Database performance. The optimal Oracle Database buffer size for the system depends on the overall system load and the relative priority of Oracle Database over other applications.
This section includes the following topics:
•
Allocating Sufficient Swap Space
(page 8-8)
•
•
(page 8-10)
•
(page 8-10)
8.3.1 Allocating Sufficient Swap Space
Try to minimize swapping because it causes significant operating system overhead. To check for swapping, use the sar
or vmstat
commands. For information about the appropriate options to use with these commands, refer to the man pages.
If the system is swapping and you must conserve memory, then:
• Avoid running unnecessary system daemon processes or application processes.
• Decrease the number of database buffers to free some memory.
• Decrease the number of operating system file buffers.
To determine the amount of swap space, run one of the following commands, depending on the platform:
Platform
Oracle Solaris
Linux
IBM AIX on POWER
Systems (64-bit)
HP-UX
Command
swap -l
, swap -s
, and zfs get volsize rpool/swap swapon -s lsps -a swapinfo -m
Monitor the use of swap space, and increase it as required. The following table describes the initially recommended relationship between installed RAM and the configured swap space requirement:
RAM
Between 1 GB and 2 GB
Swap Space
1.5 times the size of RAM
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Tuning Memory Management
RAM
Between 2 GB and 16 GB
More than 16 GB
Swap Space
Equal to the size of RAM
16 GB
To add swap space to the system, run one of the following commands, depending on the platform:
Platform
Oracle Solaris
Linux
IBM AIX on POWER
Systems (64-bit)
HP-UX
Command
Use one of the following options:
• For ZFS file system, extend the swap volume using the following command: zfs set volsize=newsize rpool/swap where
newsize
is the size of the swap volume that you want to increase.
• For a non-ZFS file system, use the following command: swap -a swapon -a chps
or mkps swapon
See Also:
• My Oracle Support note 1587357.1
• The operating system documentation for more information about these commands
Note:
Starting with 12c, Oracle Database uses the Optimized Shared Memory (OSM) model of Oracle Solaris to implement Automatic Memory Management.
Unlike DISM, OSM does not require the double allocation of swap disk space.
For swap space requirements refer to the following note:
My Oracle Support note 1010818.1
8.3.2 Monitoring Paging
Paging may not present as serious a problem as swapping, because an entire program does not have to be stored in memory to run. A small number of page-outs may not noticeably affect the performance of the system.
To detect excessive paging, run measurements during periods of fast response or idle time to compare against measurements from periods of slow response.
Use the vmstat
or sar
command to monitor paging.
Tuning Oracle Database 8-9
Tuning Memory Management
See Also:
The man pages or the operating system documentation for information about interpreting the results for the platform
In Oracle Solaris, vmstat —p
indicates the number of address translation page faults.
Address translation faults occur when a process refers to a valid page not in memory.
Analyzing memory related issues should start with checking the amount of free memory in the vmstat
output. If free memory is low, then the sr
(scan rate) column should be checked for non-zero values. This indicates that the page scanner is scanning memory pages to put back on the free list to be reused.
Anonymous (bad) paging can be observed in the vmstat -p
command output under the api
(anonymous page-in) and apo
(anonymous page-out) columns. This kind of paging takes place when the system moves anonymous pages to the swap device during a memory shortage.
If the system consistently has excessive page-out activity, then consider the following solutions:
• Install more memory.
• Move some work to another system.
• Configure the System Global Area (SGA) to use less memory.
Related Topics:
MOS Document: 1007494.1
8.3.3 Adjusting Oracle Block Size
During read operations, entire operating system blocks are read from the disk. If the database block size is smaller than the operating system file system block size, then
Input-Output bandwidth is inefficient. If you set Oracle Database block size to be a multiple of the file system block size, then you can increase performance by up to 5 percent.
The
DB_BLOCK_SIZE
initialization parameter sets the database block size. However, to change the value of this parameter, you must re-create the database.
To see the current value of the
DB_BLOCK_SIZE
parameter, run the
SHOW
PARAMETER DB_BLOCK_SIZE
command in SQL*Plus.
8.3.4 Allocating Memory Resource
You can set parameters to automatically allocate memory based on the demands of workload and the requirements of various database instances running on the same system. The
MEMORY_TARGET
parameter specifies the Oracle systemwide usable memory for that instance and automatically tunes SGA and Process Global Area
(PGA) components. The
MEMORY_MAX_TARGET
parameter identifies the value up to which the
MEMORY_TARGET
parameter can grow dynamically.
By default, the value for both these parameters is zero and there is no auto-tuning.
You can activate auto-tuning by setting the
MEMORY_TARGET
parameter to a nonzero value. To dynamically enable the
MEMORY_TARGET
parameter, the
MEMORY_MAX_TARGET
parameter must be set at startup.
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Tuning Disk Input-Output
Note:
If you just set the
MEMORY_TARGET
parameter to a nonzero value, the
MEMORY_MAX_TARGET
parameter automatically acquires this value.
The
MEMORY_TARGET
and
MEMORY_MAX_TARGET
parameters are only supported on Linux, Oracle Solaris, HP-UX, and IBM AIX on POWER Systems
(64-bit) platforms.
On Oracle Solaris, Dynamic Intimate Shared Memory is enabled for
MEMORY_TARGET
or
MEMORY_MAX_TARGET
. For more information, refer to
“Administering Oracle Database on Oracle Solaris”
(page A-1) section.
On Linux, some shared resource requirements are increased when
MEMORY_TARGET
or
MEMORY_MAX_TARGET
are enabled. For more information, refer to the "
(page B-2)" section.
Tip:
You can set the
MEMORY_TARGET
and
MEMORY_MAX_TARGET
parameters based on original setup, memory available for Oracle on the computer, and workload memory requirements.
8.4 Tuning Disk Input-Output
Balance Input-Output evenly across all available disks to reduce disk access times. For smaller databases and those not using RAID, ensure that different data files and tablespaces are distributed across the available disks.
This section contains the following topics:
•
Using Automatic Storage Management
(page 8-11)
•
Choosing the Appropriate File System Type (page 8-11)
8.4.1 Using Automatic Storage Management
If you choose to use Automatic Storage Management for database storage, then all database Input-Output is balanced across all available disk devices in the Automatic
Storage Management disk group.
By using Automatic Storage Management, you avoid manually tuning disk Input-
Output.
8.4.2 Choosing the Appropriate File System Type
Depending on the operating system, you can choose from a range of file system types.
Each file system type has different characteristics. This fact can have a substantial impact on database performance. The following table lists common file system types:
File System Platform
ZFS Oracle Solaris
S5 HP-UX
Description
Oracle Solaris ZFS file system
UNIX System V file system
Tuning Oracle Database 8-11
Monitoring Disk Performance
File System Platform
UFS Oracle Solaris, IBM AIX on
POWER Systems (64-bit), and
HP-UX
Description
Unix file system, derived from BSD UNIX
VxFS Oracle Solaris, IBM AIX on
POWER Systems (64-bit), and
HP-UX
VERITAS file system ext2/ext3
OCFS2
JFS/JFS2
Linux
Linux
IBM AIX on POWER Systems
(64-bit)
Extended file system for Linux
Oracle cluster file system
Journaled file system
GPFS IBM AIX on POWER Systems
(64-bit)
General parallel file system
The suitability of a file system for an application is usually not documented. For example, even different implementations of the UFS are hard to compare. Depending on the file system that you choose, performance differences can be up to 20 percent. If you choose to use a file system, then:
• Make a new file system partition to ensure that the hard disk is clean and unfragmented.
• Perform a file system check on the partition before using it for database files.
• Distribute disk Input-Output as evenly as possible.
• If you are not using a logical volume manager or a RAID device, then consider placing log files on a different file system from data files.
See Also:
“Tuning ZFS for Database Products” in Oracle Solaris 11.3 Tunable
Parameters Reference Manual
for more information on tuning ZFS for Oracle
Database
.
8.5 Monitoring Disk Performance
The following sections describe the procedure for monitoring disk performance:
•
Monitoring Disk Performance on Other Operating Systems
(page 8-12)
•
Using Disk Resync to Monitor Automatic Storage Management Disk Group
(page 8-13)
8.5.1 Monitoring Disk Performance on Operating Systems
To monitor disk performance, use the sar -b
and sar -u
commands.
The following table describes the columns of the sar -b
command output that are significant for analyzing disk performance:
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System Global Area
Columns
bread/s
, bwrit/s pread/s
, pwrit/s
Description
Blocks read and blocks written per second (important for file system databases)
Number of I/O operations per second on raw devices (important for raw partition database systems)
Key indicators are:
• The sum of the bread
, bwrit
, pread
, and pwrit
column values indicates the level of activity of the disk Input-Output subsystem. The higher the sum, the busier the Input-Output subsystem. The larger the number of physical drives, the higher the sum threshold number can be.
• The
%rcache
column value should be greater than 90 and the
%wcache
column value should be greater than 60. Otherwise, the system may be disk Input-Output bound.
8.5.2 Using Disk Resync to Monitor Automatic Storage Management Disk Group
Use the alter diskgroup disk online
and alter diskgroup disk offline
commands to temporarily suspend Input-Output to a set of disks. You can use these commands to perform regular maintenance tasks or upgrades such as disk firmware upgrade. If transient failures occur on some disks in a disk group, then use alter diskgroup disk online
to quickly recover the disk group.
8.6 System Global Area
The SGA is the Oracle structure that is located in shared memory. It contains static data structures, locks, and data buffers.
The maximum size of a single shared memory segment is specified by the shmmax kernel parameter.
The following table shows the recommended value for this parameter, depending on the platform:
Platform
Oracle Solaris
Linux
IBM AIX on POWER
Systems (64-bit)
HP-UX
Recommended Value
4294967295 or 4 GB minus 16 MB
Minimum of the following values:
• Half the size of the physical memory installed on the system
• 4 GB - 1 byte
NA
The size of the physical memory installed on the system
If the size of the SGA exceeds the maximum size of a shared memory segment
( shmmax
or shm_max
), then Oracle Database attempts to attach more contiguous segments to fulfill the requested SGA size. The shmseg
kernel parameter specifies the maximum number of segments that can be attached by any process. Set the following initialization parameters to control the size of the SGA:
Tuning Oracle Database 8-13
System Global Area
•
DB_CACHE_SIZE
•
DB_BLOCK_SIZE
•
JAVA_POOL_SIZE
•
LARGE_POOL_SIZE
•
LOG_BUFFERS
•
SHARED_POOL_SIZE
Alternatively, set the
SGA_TARGET
initialization parameter to enable automatic tuning of the SGA size.
Use caution when setting values for these parameters. When values are set too high, too much of the physical memory is devoted to shared memory. This results in poor performance.
An Oracle Database configured with Shared Server requires a higher setting for the
SHARED_POOL_SIZE
initialization parameter, or a custom configuration that uses the
LARGE_POOL_SIZE
initialization parameter. If you installed the database with Oracle
Universal Installer, then the value of the
SHARED_POOL_SIZE
parameter is set automatically by Oracle Database Configuration Assistant. However, if you created a database manually, then increase the value of the
SHARED_POOL_SIZE
parameter in the parameter file by 1 KB for each concurrent user.
Sufficient shared memory must be available to each Oracle process to address the entire SGA:
•
Determining the Size of the SGA (page 8-14)
•
System Resource Verifier Utility
(page 8-14)
•
Guidelines for Setting Semaphore Parameters
(page 8-15)
•
Shared Memory on IBM AIX on POWER Systems (64-Bit)
(page 8-16)
8.6.1 Determining the Size of the SGA
You can determine the SGA size in one of the following ways:
• Run the following SQL*Plus command to display the size of the SGA for a running database:
SQL> SHOW SGA
The result is shown in bytes.
• Start the database instance to view the size of the SGA displayed next to the Total
System Global Area heading.
• Run the ipcs
command as the oracle
user.
8.6.2 System Resource Verifier Utility
The System Resource Verifier utility ( sysresv
) is available with Oracle8
i
and later releases. It provides Oracle instance and operating system resource information for the
Oracle system identifiers (
ORACLE_SID
) that you specify. This utility is located in
$ORACLE_HOME/bin
, but it can be used from other locations.
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System Global Area
8.6.2.1 Purpose of the sysresv Utility
Use the sysresv
utility to display the status of an Oracle instance and identify the operating system resources it uses, such as the memory and semaphore parameters.
This utility is especially useful when multiple instances are running. For example, if an instance is not responsive, then you can use this utility to remove operating system resources.
You can use this utility when an Oracle instance has crashed or was aborted, and memory and semaphores related to this instance were not cleaned up automatically.
This utility is also useful in determining which Oracle instance is running.
8.6.2.2 Preconditions for Using sysresv
To use the sysresv
utility, you must have access to the System Global Area (SGA).
To access the SGA, you must be the Oracle owner or a member of the group that owns the Oracle binary.
8.6.2.3 Syntax for sysresv
The syntax for the sysresv
utility is as follows: sysresv [-i] [-f] [-d on|off] [-l sid1[ sid2 ...]]
Where:
•
-i
Prompt before removing IPC resources for each sid
•
-f
Remove IPC resources without prompting for confirmation. This flag overrides the
-i option
•
-d on|off
List IPC resources for each sid
if on. If not specified, the default for
-d
is on
•
-l sid1 [sid2 sid3]
run the sysresv
check against one or more spacedelimited system identifiers
If sysresv
is used without flags, then it reports IPC resources for the Oracle instance identified by the
$ORACLE_SID
environment variable in the Oracle installation owner user profile list of environment variables.
8.6.2.4 Examples of Using sysresv
The following example shows how to use the sysresv
utility:
$ sysresv
IPV Resources for ORACLE_SID "sales" :
Shared Memory:
ID KEY
10345 0x51c051ad
Semaphores
ID
10345 0x51c051ad
Oracle Instance alive for sid "sales"
8.6.3 Guidelines for Setting Semaphore Parameters
Use the following guidelines only if the default semaphore parameter values are too low to accommodate all Oracle processes:
Tuning Oracle Database 8-15
System Global Area
Note:
Oracle recommends that you see the operating system documentation for more information about setting semaphore parameters.
1.
Calculate the minimum total semaphore requirements using the following formula: sum (process parameters of all database instances on the system) + overhead for oracle background processes + system and other application requirements
2.
Set semmns
(maximum number of semaphores allowed for the server) to this total.
3.
Set semmsl
(maximum number of semaphores in a semaphore set) to 250.
4.
Set semmni
(maximum number of semaphore sets) to semmns/semmsl rounded up to the nearest multiple of 1024.
See Also:
My Oracle Support note 226209.1, "Linux: How to Check Current Shared
Memory, Semaphore Values," at the following URL: https://support.oracle.com/CSP/main/article?
cmd=show&type=NOT&id=226209.1
The semaphore parameters semmns
, semmsl
, and semmni
are obsolete on
Oracle Solaris 10 and later. See My Oracle Support note 1006158.1: https://support.oracle.com/CSP/main/article?
cmd=show&type=NOT&id=1006158.1
8.6.4 Shared Memory on IBM AIX on POWER Systems (64-Bit)
Note:
The information in this section applies only to IBM AIX on POWER Systems
(64-bit).
Shared memory uses common virtual memory resources across processes. Processes share virtual memory segments through a common set of virtual memory translation resources, for example, tables and cached entries, for improved performance.
Shared memory can be pinned to prevent paging and to reduce Input-Output overhead. To perform this, set the
LOCK_SGA
parameter to true
. On IBM AIX on
POWER Systems (64-bit) 5L, the same parameter activates the large page feature whenever the underlying hardware supports it.
Run the following command to make pinned memory available to Oracle Database:
$ /usr/sbin/vmo -r -o v_pinshm=1
Run a command similar to the following to set the maximum percentage of real memory available for pinned memory, where
percent_of_real_memory
is the maximum percent of real memory that you want to set:
$ /usr/sbin/vmo -r -o maxpin percent=percent_of_real_memory
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System Global Area
When using the maxpin percent
option, it is important that the amount of pinned memory exceeds the Oracle SGA size by at least 3 percent of the real memory on the system, enabling free pinnable memory for use by the kernel. For example, if you have
2 GB of physical memory and you want to pin the SGA by 400 MB (20 percent of the
RAM), then run the following command:
$ /usr/sbin/vmo -r -o maxpin percent=23
Note:
The default maxpin percent
value, which is set at 80 percent
, works for most installations.
Use the svmon
command to monitor the use of pinned memory during the operation of the system. Oracle Database attempts to pin memory only if the
LOCK_SGA parameter is set to true
. If the SGA size exceeds the size of memory available for pinning, then the portion of the SGA exceeding these sizes is allocated to ordinary shared memory.
Large Page Feature on IBM AIX on POWER Systems (64-Bit) POWER4 and
POWER5 Based Systems
To turn on and reserve 10 large pages each of size 16 MB on a POWER4 or POWER5 system, run the following command:
$ /usr/sbin/vmo -r -o lgpg_regions=10 -o lgpg_size=16777216
This command proposes bosboot
and warns that a restart is required for the changes to take affect.
Oracle recommends specifying enough large pages to contain the entire SGA. The
Oracle database instance attempts to allocate large pages when the
LOCK_SGA parameter is set to true
.
The 16 MB pages are always pinned, and cannot be used for standard memory. If a pool of 16 MB size pages is configured, then this memory is unusable for allocation of standard memory even if no other application is currently using large pages.
The POWER5 based systems support 64 K pages. Oracle uses them for SGA if they are available. These 64K pages do not require any additional configuration and do not depend on
LOCK_SGA
parameter setting.
To monitor use of large pages, use the following command:
$ vmstat -P all
For the IBM AIX on POWER Systems (64-bit) operating system to use 16 MB pages, or pinned memory when allocating shared memory, the Oracle user ID must have
CAP_BYPASS_RAC_VMM
and
CAP_PROPAGATE
capabilities. User ID that is used to start the database instance must also have the same capabilities. In particular, when using large pages on an Oracle Real Application Cluster (Oracle RAC) database, where the srvctl
command is used to start and stop the Oracle RAC database instances, it is also necessary to set the
CAP_BYPASS_RAC_VMM
and
CAP_PROPAGATE
capabilities for the root
user.
Tuning Oracle Database 8-17
Tuning the Operating System Buffer Cache
See Also:
The IBM AIX on POWER Systems (64-bit) documentation for more information about enabling and tuning pinned memory and large pages
Capabilities can be set and examined using the following commands:
• Run the following command to check the current capabilities:
$ lsuser –a capabilities oracle
• Add the
CAP_BYPASS_RAC_VMM
and
CAP_PROPAGATE
capabilities to this user
ID:
$ chuser capabilities=CAP_BYPASS_RAC_VMM,CAP_PROPAGATE oracle
Note:
Only the root
user can display and set the capabilities attribute.
8.7 Tuning the Operating System Buffer Cache
Adjust the size of Oracle Database buffer cache. If memory is limited, then adjust the operating system buffer cache.
The operating system buffer cache holds blocks of data in memory while they are being transferred from memory to disk, or from disk to memory.
Oracle Database buffer cache is the area in memory that stores Oracle Database buffers.
If the amount of memory on the system is limited, then make a corresponding decrease in the operating system buffer cache size.
Use the sar
command to determine which buffer caches you must increase or decrease.
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A
Administering Oracle Database on Oracle
Solaris
This appendix contains information about administering Oracle Database on Oracle
Solaris.
It contains the following topics:
Oracle Solaris Shared Memory Environment
(page A-1)
About Creating Resource Pools on Oracle Solaris Systems (page A-4)
About Multi-CPU Binding Functionality (page A-4)
A.1 Oracle Solaris Shared Memory Environment
This section describes how Oracle Database uses shared memory models like
Optimized Shared Memory (OSM), Intimate Shared Memory (ISM), and Dynamic
Intimate Shared Memory (DISM).
It contains the following topics:
•
(page A-1)
•
Checking for Optimized Shared Memory (page A-2)
•
(page A-2)
•
Checking for ISM or DISM (page A-2)
•
About the oradism Utility (page A-3)
•
How Oracle Database Decides Between OSM_ ISM and DISM
(page A-3)
A.1.1 About Optimized Shared Memory
Starting with 12c, Oracle Database uses the Optimized Shared Memory (OSM) model of Oracle Solaris on Oracle Solaris 10 1/13 or later and Oracle Solaris 11 SRU 7.5 or later systems to implement Automatic Memory Management.
OSM allows dynamic resizing of System Global Area (SGA) without restarting the instance. It does not use the oradism
utility and swap disk space. OSM is NUMAoptimized.
Administering Oracle Database on Oracle Solaris A-1
Oracle Solaris Shared Memory Environment
A.1.2 Checking for Optimized Shared Memory
Note:
Ensure that you set the
MEMORY_MAX_TARGET
to a greater value than
MEMORY_TARGET
to utilize Optimized Shared Memory.
To verify if Oracle Solaris uses Optimized Shared Memory (OSM), enter the following command:
$ ipcs -dm
If the column
ALLOC
shows an integer, it specifies that OSM is in use. If the column
ALLOC
shows a hyphen, it specifies that OSM is not in use.
A.1.3 About ISM and DISM
On Oracle Solaris systems, Oracle Database uses Intimate Shared Memory (ISM) for shared memory segments because it shares virtual memory resources between Oracle processes. ISM causes the physical memory for the entire shared memory segment to be locked automatically.
On Oracle Solaris 10 systems prior to Oracle Solaris 10 1/13 and Oracle Solaris 11 SRU
7.5, Dynamic Intimate Shared Memory (DISM) is available. This enables Oracle
Database to share virtual memory resources between processes sharing the segment, and at the same time, enables memory paging. The operating system does not have to lock down physical memory for the entire shared memory segment.
A.1.4 Checking for ISM or DISM
On Oracle Solaris, to determine if shared memory is in use, use the ipcs -im command. For example:
% ipcs -im
IPC status from <system> as of Thu Aug 19 01:09:30 PDT 2013
T ID KEY MODE OWNER GROUP ISMATTCH
Shared Memory: m 11 0xacea4150 --rw-rw---- oracle dba 160
The
ISMATTCH
field shows 160 processes attached to this shared memory segment.
However,
ISMATTCH does not distinguish between Intimate Shared Memory (ISM) and Dynamic Intimate Shared Memory (DISM).
On Oracle Solaris 10 systems prior to Oracle Solaris 10 1/13 and Oracle Solaris 11 SRU
7.5, to identify if ISM or DISM is in use, or which memory locking service is active, use the pmap –xs
command. For example:
% ps -ef | grep ora | grep smon oracle 12524 1 0 05:40:13 ? 0:25 ora_smon_prod
% pmap –xs 12524 | grep ism
0000000380000000 38010880 38010880 - 38010880 256M rwxsR [ ism shmid=0xb ]
0000000C90000000 131072 131072 - 131072 4M rwxsR [ ism shmid=0xb ]
0000000C98000000 16 16 - 16 8K rwxsR [ ism shmid=0xb ]
A-2 Oracle Database Administrator's Reference
Oracle Solaris Shared Memory Environment
Note:
The ps —ef
command lists the background processes that are running. This information is required to determine if an Oracle database instance is running.
The output from the pmap –xs
command shows three ism
address ranges implying that ISM is in use. If DISM locks the memory ranges, then the output shows
dism address ranges.
A.1.5 About the oradism Utility
Oracle Database uses the oradism
utility to lock and unlock shared memory. The oradism
utility is automatically set up during installation. It is not required to perform any configuration tasks to use dynamic SGA.
The process name for the oradism
utility is ora_dism_sid
, where sid
is the system identifier. When using DISM, this process is started during instance startup, and automatically quits when the instance is shut down.
If a message is displayed in the alert log saying that the oradism
utility is not set up correctly, then verify that the oradism
utility is located in the
$ORACLE_HOME/bin directory and that it has superuser privileges.
Note:
Optimized Shared Memory (OSM) does not use the oradism
utility.
A.1.6 How Oracle Database Decides Between OSM, ISM and DISM
Oracle Database automatically uses Optimized Shared Memory (OSM) on Oracle
Solaris systems where OSM is available. See "
(page A-1)" for more information on OSM.
On systems where OSM is not available, Oracle Database automatically selects
Intimate Shared Memory (ISM) or Dynamic Intimate Shared Memory (DISM) based on the following criteria:
• Oracle Database uses DISM if it is available on the system, and if the value of the
SGA_MAX_SIZE
initialization parameter is larger than the size required for all
SGA components combined. This enables Oracle Database to lock only the amount of physical memory that is used.
• Oracle Database uses ISM if the entire shared memory segment is in use at startup or if the value of the
SGA_MAX_SIZE
parameter equals or smaller than the size required for all SGA components combined.
Regardless of whether Oracle Database uses ISM or DISM, it can always exchange the memory between dynamically sizable components such as the buffer cache, the shared pool, and the large pool after it starts an instance. Oracle Database can relinquish memory from one dynamic SGA component and allocate it to another component.
Because shared memory segments are not implicitly locked in memory, when using
DISM, Oracle Database explicitly locks shared memory that is currently in use at startup. When a dynamic SGA operation uses more shared memory, Oracle Database explicitly performs a lock operation on the memory that is put to use. When a dynamic
SGA operation releases shared memory, Oracle Database explicitly performs an
Administering Oracle Database on Oracle Solaris A-3
About Creating Solaris Resource Pools unlock operation on the memory that is freed, so that it becomes available to other applications.
Note:
Do not set the
LOCK_SGA
parameter to
TRUE
in the server parameter file. If you do, then Oracle Database 12c cannot start.
A.2 About Creating Solaris Resource Pools
Solaris Resource Pools improve database performance by associating a dedicated set of CPUs to a database instance. Each database instance can only use the resources in its resource pool.
When consolidating on a large server, you may want to restrict the database to a specific subset of the CPU and memory. This feature makes it easy to enable CPU and memory restrictions for an Oracle Database instance.
Use the setup_resource_pool.sh
script to create Solaris Resource Pools.
Download this script from note 1928328.1 on the My Oracle Support website: https://support.oracle.com/CSP/main/article?
cmd=show&type=NOT&id=1928328.1
A.3 About Multi-CPU Binding Functionality
You can use Multi-CPU Binding (MCB) as part of your resource management policy to improve performance.
Multi-CPU binding (MCB) is an Oracle Solaris projects resource management functionality that binds a project to a specific set of CPUs, but does not bind the CPUs exclusively. MCB allows other processes also to use these CPUs, and allows overlapping of partitions. MCB is supported on Oracle Solaris 11.3 and later.
The resource pools feature also allows binding of CPUs. However, this method requires hard partitioning of processors in the system. Resource pools does not allow overlapping of partitions.
You can assign, modify, or remove MCBs through Oracle Solaris projects. Use the standard command-line tools projadd(1M)
and projmod(1M) to create or modify the project file.
For database users, the advantages of using MCB over resource pools include:
• The ability to bind an Oracle instance to a particular NUMA location for performance, such as, near a specific I/O or networking device.
• The ability to bind multiple Oracle instances to different cores or sockets on a host to increase performance isolation without the need of a privileged administrator to partition the system.
See Also:
"Using Projects to Assign, Modify, and Remove Multi-CPU Binding" and
"How to Use Projects to Assign, Modify, and Remove Multi-CPU Binding" in
Administering Resource Management in Oracle Solaris 11.3
.
A-4 Oracle Database Administrator's Reference
B
Administering Oracle Database on Linux
This appendix contains information about administering Oracle Database on Linux.
It contains the following topics:
•
Supporting Asynchronous Input-Output
(page B-1)
•
Asynchronous Input-Output Support (page B-2)
•
Enabling Direct Input-Output Support (page B-2)
•
Enabling Simultaneous Multithreading
(page B-2)
•
Allocating Shared Resources (page B-2)
•
About Creating cgroups on Linux Systems
(page B-4)
•
(page B-4)
Note:
Starting with Oracle Database 11g Release 2 (11.2), Linux x86-64 and IBM:
Linux on System z media does not contain Linux x86 binaries.
B.1 Supporting Asynchronous Input-Output
Note:
On Linux, Automatic Storage Management uses asynchronous Input-Output by default. Asynchronous Input-Output is not supported for database files stored on Network File Systems.
Oracle Database supports kernel asynchronous Input-Output. Asynchronous Input-
Output is enabled by default on raw volumes. Automatic Storage Management uses asynchronous Input-Output by default.
By default, the
DISK_ASYNCH_IO
initialization parameter in the parameter file is set to TRUE. To enable asynchronous Input-Output on file system files:
1.
Ensure that all Oracle Database files are located on file systems that support asynchronous Input-Output.
2.
Set the
FILESYSTEMIO_OPTIONS
initialization parameter in the parameter file to
ASYNCH
or
SETALL
.
Administering Oracle Database on Linux B-1
Asynchronous Input-Output Support
Note:
If the file system files are managed through ODM library interface or Direct
NFS Client, asynchronous Input-Output is enabled by default. There is no need to set
FILESYSTEMIO_OPTIONS
to enable asynchronous Input-Output in these environments.
B.2 Asynchronous Input-Output Support
Note:
On Linux, Automatic Storage Management uses asynchronous Input-Output by default. Asynchronous Input-Output is not supported for database files stored on Network File Systems.
Oracle Database supports kernel asynchronous Input-Output. This feature is disabled by default.
By default, the
DISK_ASYNCH_IO
initialization parameter in the parameter file is set to TRUE to enable asynchronous I/O on raw devices. To enable asynchronous Input-
Output on file system files:
1.
Ensure that all Oracle Database files are located on file systems that support asynchronous Input-Output.
2.
Set the
FILESYSTEMIO_OPTIONS
initialization parameter in the parameter file to
ASYNCH
to enable asynchronous Input-Output. If you want to enable both asynchronous Input-Output and direct Input-Output, set the
FILESYSTEMIO_OPTIONS
initialization parameter in the parameter file to
SETALL.
B.3 Enabling Direct Input-Output Support
Direct Input-Output support is available and supported on Linux.
To enable direct Input-Output support:
• Set the
FILESYSTEMIO_OPTIONS
initialization parameter to
DIRECTIO
.
• Set the
FILESYSTEMIO_OPTIONS
initialization parameter in the parameter file to
SETALL
, which will enable both asynchronous Input-Output and direct Input-
Output.
B.4 Enabling Simultaneous Multithreading
If Simultaneous Multithreading is enabled, then the v$osstat
view reports two additional rows corresponding to the online logical (
NUM_LCPUS
) and virtual CPUs
(
NUM_VCPUS
).
B.5 Allocating Shared Resources
To use the
MEMORY_TARGET
or
MEMORY_MAX_TARGET
feature, the following kernel parameters must be modified.
B-2 Oracle Database Administrator's Reference
Allocating Shared Resources
•
/dev/shm
mount point should be equal in size or larger than the value of
SGA_MAX_SIZE
, if set, or should be set to be at least
MEMORY_TARGET
or
MEMORY_MAX_TARGET
, whichever is larger. For example, with
MEMORY_MAX_TARGET=4GB
only set, to create a 4 GB system on the
/dev/shm mount point:
– Run the following command as the root
user:
# mount -t tmpfs shmfs -o size=4g /dev/shm
– Ensure that the in-memory file system is mounted when the system restarts, add an entry in the
/etc/fstab
file similar to the following:
tmpfs /dev/shm tmpfs size=4g 0
• The number of file descriptors for each Oracle instance are increased by
512*
PROCESSES
. Therefore, the maximum number of file descriptors should be at least this value, plus some more for the operating system requirements. For example, if the cat /proc/sys/fs/file-max
command returns 32768 and
PROCESSES
are 100, you can set it to 6815744 or higher as root
, to have 51200 available for Oracle. Use one of the following options to set the value for the file-max
descriptor.
– Run the following command: echo 6815744 > /proc/sys/fs/file-max
OR
– Modify the following entry in the
/etc/sysctl.conf
file and restart the system as root
.
fs.file-max = 6815744
• Per-process number of file descriptors must be at least 512. For example, as root run the following command.
– On bash and sh:
# ulimit -n
– On csh:
# limit descriptors
If the preceding command returns 200, then run the following command to set the value for the per processor file descriptors limit, for example to 1000:
– On bash and sh:
# sudo sh
# ulimit -n 1000
– On csh:
# sudo sh
# limit descriptors 1000
•
MEMORY_TARGET
and
MEMORY_MAX_TARGET
cannot be used when
LOCK_SGA
is enabled.
MEMORY_TARGET
and
MEMORY_MAX_TARGET
also cannot be used with huge pages on Linux.
Administering Oracle Database on Linux B-3
About Creating Cgroups on Linux Systems
B.6 About Creating Cgroups on Linux Systems
Cgroups, or control groups, improve database performance by associating a dedicated set of CPUs to a database instance. Each database instance can only use the resources in its cgroup.
When consolidating on a large server, you may want to restrict the database to a specific subset of the CPU and memory. This feature makes it easy to enable CPU and memory restrictions for an Oracle Database instance.
Use the setup_processor_group.sh
script to create cgroups. Download this script from note 1585184.1 on the My Oracle Support website: https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=1585184.1
B.7 Overview of HugePages
HugePages is a feature integrated into the Linux kernel 2.6. Enabling HugePages makes it possible for the operating system to support memory pages greater than the default (usually 4 KB). Using very large page sizes can improve system performance by reducing the amount of system resources required to access page table entries.
HugePages is useful for both 32-bit and 64-bit configurations. HugePage sizes vary from 2 MB to 256 MB, depending on the kernel version and the hardware architecture.
For Oracle Databases, using HugePages reduces the operating system maintenance of page states, and increases Translation Lookaside Buffer (TLB) hit ratio.
Note:
Transparent Hugepages is currently not an alternative to manually configure
HugePages.
This section includes the following topics:
•
Reviewing HugePages Memory Allocation (page B-4)
•
(page B-5)
•
(page B-5)
•
Configuring HugePages on Linux
(page B-6)
•
Restrictions for HugePages Configurations (page B-8)
•
Disabling Transparent HugePages (page B-8)
B.7.1 Reviewing HugePages Memory Allocation
Review this information if your operating system has HugePages enabled.
On Linux platform installations, Oracle recommends that you use HugePages to obtain the best performance for Oracle Databases. When you upgrade Oracle Grid
Infrastructure and Oracle Databases on servers that have HugePages enabled, Oracle recommends that you review your HugePages memory allocation requirements.
GIMR and HugePages Memory
Oracle Grid Infrastructure installations include the Grid Infrastructure Management
Repository (GIMR). When HugePages is configured on cluster member nodes, the
B-4 Oracle Database Administrator's Reference
Overview of HugePages
GIMR system global area (SGA) is installed into HugePages memory. The GIMR SGA occupies up to 1 GB of HugePages memory. Oracle Grid Infrastructure starts up before Oracle Databases installed on the cluster.
If your cluster member node operating system memory allocations to HugePages are insufficient for the size of the SGAs for all of the Oracle Database instances on the cluster, then you may find that one or more of your Oracle Database SGAs are mapped to regular pages, instead of Huge Pages, which reduces expected performance. To avoid this issue, when you plan your upgrade, ensure that the memory you reserve for HugePages is large enough to accommodate your memory requirements.
Allocate memory to HugePages large enough for all databases planned to run SGA on the cluster, and to accommodate the SGA for the Grid Infrastructure Management
Repository.
B.7.2 Using HugePages on Linux
To enable Oracle Database to use large pages (sometimes called HugePages) on Linux, set the value of the vm.nr_hugepages
kernel parameter to specify the number of large pages that you want to reserve. You must specify adequate large pages to hold the entire SGA for the database instance. To determine the required parameter value, divide the SGA size for the instance by the size of a large page, then round up the result to the nearest integer.
To determine the default large page size, run the following command:
# grep Hugepagesize /proc/meminfo
For example, if
/proc/meminfo
lists the large page size as 2 MB, and the total SGA size for the instance is 1.6 GB, then set the value for the vm.nr_hugepages
kernel parameter to 820 (1.6 GB / 2 MB = 819.2).
B.7.3 Tuning SGA With HugePages
Without HugePages, the operating system keeps each 4 KB of memory as a page.
When it allocates pages to the database System Global Area (SGA), the operating system kernel must continually update its page table with the page lifecycle (dirty, free, mapped to a process, and so on) for each 4 KB page allocated to the SGA.
With HugePages, the operating system page table (virtual memory to physical memory mapping) is smaller, because each page table entry is pointing to pages from
2 MB to 256 MB.
Also, the kernel has fewer pages whose lifecycle must be monitored. For example, if you use HugePages with 64-bit hardware, and you want to map 256 MB of memory, you may need one page table entry (PTE). If you do not use HugePages, and you want to map 256 MB of memory, then you must have 256 MB * 1024 KB/4 KB = 65536 PTEs.
HugePages provides the following advantages:
• Increased performance through increased TLB hits
• Pages are locked in memory and never swapped out, which provides RAM for shared memory structures such as SGA
• Contiguous pages are preallocated and cannot be used for anything else but for
System V shared memory (for example, SGA)
Administering Oracle Database on Linux B-5
Overview of HugePages
• Less bookkeeping work for the kernel for that part of virtual memory because of larger page sizes
B.7.4 Configuring HugePages on Linux
Complete the following steps to configure HugePages on the computer:
1.
Run the following command to determine if the kernel supports HugePages:
2.
3.
$ grep Huge /proc/meminfo
Some Linux systems do not support HugePages by default. For such systems, build the Linux kernel using the
CONFIG_HUGETLBFS
and
CONFIG_HUGETLB_PAGE configuration options.
CONFIG_HUGETLBFS
is located under File Systems and
CONFIG_HUGETLB_PAGE
is selected when you select
CONFIG_HUGETLBFS
.
Edit the memlock
setting in the
/etc/security/limits.conf
file. The memlock
setting is specified in KB, and the maximum locked memory limit should be set to at least 90 percent of the current RAM when HugePages memory is enabled and at least 3145728 KB (3 GB) when HugePages memory is disabled.
For example, if you have 64 GB RAM installed, then add the following entries to increase the maximum locked-in-memory address space:
* soft memlock 60397977
* hard memlock 60397977
4.
5.
6.
You can also set the memlock
value higher than your SGA requirements.
Log in as oracle
user again and run the ulimit -l
command to verify the new memlock setting:
$ ulimit -l
60397977
Run the following command to display the value of
Hugepagesize
variable:
$ grep Hugepagesize /proc/meminfo
Complete the following procedure to create a script that computes recommended values for hugepages
configuration for the current shared memory segments:
a.
b.
Create a text file named hugepages_settings.sh
.
Add the following content in the file:
#!/bin/bash
#
# hugepages_settings.sh
#
# Linux bash script to compute values for the
# recommended HugePages/HugeTLB configuration
#
# Note: This script does calculation for all shared memory
# segments available when the script is run, no matter it
# is an Oracle RDBMS shared memory segment or not.
# Check for the kernel version
KERN=`uname -r | awk -F. '{ printf("%d.%d\n",$1,$2); }'`
# Find out the HugePage size
HPG_SZ=`grep Hugepagesize /proc/meminfo | awk {'print $2'}`
# Start from 1 pages to be on the safe side and guarantee 1 free HugePage
B-6 Oracle Database Administrator's Reference
Overview of HugePages
7.
c.
NUM_PG=1
# Cumulative number of pages required to handle the running shared memory segments for SEG_BYTES in `ipcs -m | awk {'print $5'} | grep "[0-9][0-9]*"` do
MIN_PG=`echo "$SEG_BYTES/($HPG_SZ*1024)" | bc -q`
if [ $MIN_PG -gt 0 ]; then
NUM_PG=`echo "$NUM_PG+$MIN_PG+1" | bc -q`
fi done
# Finish with results case $KERN in
'2.4') HUGETLB_POOL=`echo "$NUM_PG*$HPG_SZ/1024" | bc -q`;
echo "Recommended setting: vm.hugetlb_pool = $HUGETLB_POOL" ;;
'2.6'|'3.8') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
*) echo "Unrecognized kernel version $KERN. Exiting." ;; esac
# End
Run the following command to change the permission of the file:
$ chmod +x hugepages_settings.sh
Run the hugepages_settings.sh script to compute the values for hugepages
configuration:
$ ./hugepages_settings.sh
Note:
Before running this script, ensure that all the applications that use hugepages run.
8.
9.
Set the following kernel parameter, where value is the HugePages value that you determined in step
(page B-7):
# sysctl -w vm.nr_hugepages=value
To ensure that HugePages is allocated after system restarts, add the following entry to the
/etc/sysctl.conf
file, where value is the HugePages value that
you determined in step 7 (page B-7):
vm.nr_hugepages=value
10.
Run the following command to check the available hugepages
:
$ grep Huge /proc/meminfo
11.
Restart the instance.
12.
Run the following command to check the available hugepages
(1 or 2 pages free):
$ grep Huge /proc/meminfo
Note:
If you cannot set your HugePages allocation using nr_hugepages
, then your available memory may be fragmented. Restart your server for the Hugepages allocation to take effect.
Administering Oracle Database on Linux B-7
Overview of HugePages
B.7.5 Restrictions for HugePages Configurations
HugePages has the following limitations:
• You must unset both the
MEMORY_TARGET
and
MEMORY_MAX_TARGET initialization parameters. For example, to unset the parameters for the database instance, use the command
ALTER SYSTEM RESET
.
• Automatic Memory Management (AMM) and HugePages are not compatible.
When you use AMM, the entire SGA memory is allocated by creating files under
/dev/shm
. When Oracle Database allocates SGA with AMM, HugePages are not reserved. To use HugePages on Oracle Database 12c, You must disable
AMM.
• If you are using VLM in a 32-bit environment, then you cannot use HugePages for the Database Buffer cache. You can use HugePages for other parts of the SGA, such as shared_pool
, large_pool
, and so on. Memory allocation for VLM
(buffer cache) is done using shared memory file systems ( ramfs/tmpfs/shmfs
).
Memory file systems do not reserve or use HugePages.
• HugePages are not subject to allocation or release after system startup, unless a system administrator changes the HugePages configuration, either by modifying the number of pages available, or by modifying the pool size. If the space required is not reserved in memory during system startup, then HugePages allocation fails.
• Ensure that HugePages is configured properly as the system may run out of memory if excess HugePages is not used by the application.
• If there is insufficient HugePages when an instance starts and the initialization parameter use_large_pages
is set to only
, then the database fails to start and an alert log message provides the necessary information on Hugepages.
B.7.6 Disabling Transparent HugePages
Oracle recommends that you disable Transparent HugePages before you start installation.
Transparent HugePages memory differs from standard HugePages memory because the kernel khugepaged
thread allocates memory dynamically during runtime.
Standard HugePages memory is pre-allocated at startup, and does not change during runtime.
Note:
Although Transparent HugePages is disabled on UEK2 and later UEK kernels, Transparent HugePages may be enabled by default on your Linux system.
Transparent HugePages memory is enabled by default with Red Hat Enterprise Linux
6, Red Hat Enterprise Linux 7, SUSE 11, Oracle Linux 6, and Oracle Linux 7 with earlier releases of Oracle Linux Unbreakable Enterprise Kernel 2 (UEK2) kernels.
Transparent HugePages memory is disabled by default in UEK2 and later UEK kernels.
Transparent HugePages can cause memory allocation delays during runtime. To avoid performance issues, Oracle recommends that you disable Transparent HugePages on
B-8 Oracle Database Administrator's Reference
Overview of HugePages all Oracle Database servers. Oracle recommends that you instead use standard
HugePages for enhanced performance.
To check if Transparent HugePages is enabled, run one of the following commands as the root user:
Red Hat Enterprise Linux kernels:
# cat /sys/kernel/mm/redhat_transparent_hugepage/enabled
Other kernels:
# cat /sys/kernel/mm/transparent_hugepage/enabled
The following is a sample output that shows Transparent HugePages are being used as the [always] flag is enabled.
[always] never
Note:
If Transparent HugePages is removed from the kernel, then neither
/sys/ kernel/mm/transparent_hugepage
nor
/sys/kernel/mm/ redhat_transparent_hugepage files
do not exist.
To disable Transparent HugePages:
1.
Add the following entry to the kernel boot line in the
/etc/grub.conf
file: transparent_hugepage=never
2.
For example: title Oracle Linux Server (2.6.32-300.25.1.el6uek.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-300.25.1.el6uek.x86_64 ro root=LABEL=/ transparent_hugepage=never
initrd /initramfs-2.6.32-300.25.1.el6uek.x86_64.img
Restart the system to make the changes permanent.
Administering Oracle Database on Linux B-9
Overview of HugePages
B-10 Administrator's Reference
C
Administering Oracle Database on IBM AIX on POWER Systems (64-Bit)
This appendix contains information about administering Oracle Database on IBM AIX on POWER Systems (64-bit).
It includes the following topics:
•
(page C-1)
•
Disk Input-Output Issues (page C-4)
•
CPU Scheduling and Process Priorities (page C-9)
•
AIXTHREAD_SCOPE Environment Variable (page C-9)
•
Network Information Service external naming support (page C-9)
•
Configuring IBM Java Secure Socket Extension Provider with Oracle JDBC Thin
(page C-10)
C.1 Memory and Paging
Memory contention occurs when processes require more memory than is available. To cope with the shortage, the system pages the programs and data between memory and disks.
This section contains the following topics:
•
•
Allocating Sufficient Paging Space (page C-2)
•
•
Setting the Database Block Size
(page C-3)
•
Tuning the Log Archive Buffers
(page C-4)
•
Input-Output Buffers and SQL*Loader
(page C-4)
C.1.1 Kernel Parameters
Oracle recommends to use the default AIX kernel settings. You must adjust the kernel settings as appropriately recommended by IBM support only.
Administering Oracle Database on IBM AIX on POWER Systems (64-Bit) C-1
Memory and Paging
Note:
Adjusting the Restricted Tunables parameter without the guidance from IBM support can have an undesirable impact on the system stability and performance.
C.1.2 Allocating Sufficient Paging Space
Inadequate paging space (swap space) usually causes the system to stop responding or show very slow response times. On IBM AIX on POWER Systems (64-bit), you can dynamically add paging space on raw disk partitions. The amount of paging space you should configure depends on the amount of physical memory present and the paging space requirements of the applications. Use the lsps
command to monitor paging space use and the vmstat
command to monitor system paging activities. To increase the paging space, use the smit pgsp
command.
If paging space is preallocated, then Oracle recommends that you set the paging space to a value larger than the amount of RAM. But on IBM AIX on POWER Systems (64bit), paging space is not allocated until required. The system uses swap space only if it runs out of real memory. If the memory is sized correctly, then there is no paging and the page space can be small. Workloads where the demand for pages does not fluctuate significantly perform well with a small paging space. Workloads likely to have peak periods of increased paging require enough paging space to handle the peak number of pages.
As a general rule, an initial setting for the paging space is half the size of RAM plus 4
GB, up to the size of a single internal disk. Monitor the paging space use with the lsps -a
command, and monitor the system paging activities using the vmstat command. The metric percent used in the output of lsps -a
is typically less than 25 percent on a healthy system. A properly sized deployment requires very little paging space because an excessive amount of swapping severely impacts performance.
Excessive use of paging space and swapping indicates that the RAM on the system may be undersized.
Caution:
Do not undersize the paging space. If you do, then the system terminates active processes when it runs out of space. However, oversizing the paging space has little or no negative impact.
Oracle documentation suggests the following values as a starting point for an Oracle
Database:
RAM
Between 1 GB and 2 GB
Between 2 GB and 16 GB
More than 16 GB
Swap Space
1.5 times the size of RAM
Equal to the size of RAM
16 GB
The RAM and swap space values for Oracle Grid Infrastructure are as follows:
• Between 4 GB RAM and 16 GB RAM, the swap space must be equal to the size of
RAM.
• For more than 16 GB RAM, the swap space must be equal to 16 GB.
C-2 Oracle Database Administrator's Reference
Memory and Paging
Because the individual server environment varies, some additional memory may be warranted in an Oracle Database 12.1 environment, based on the increased 12.1
memory footprint and increasing page size from 4 KB to 64 KB. The workload may need to be rebalanced to reduce paging, which impacts system performance.
C.1.3 Controlling Paging
Constant and excessive paging indicates that the real memory is over-committed. In general, you should:
• Avoid constant paging unless the system is equipped with very fast expanded storage that makes paging between memory and expanded storage much faster than Oracle Database can read and write data between the SGA and disks.
• Allocate limited memory resource to where it is most beneficial to system performance. It is sometimes a recursive process of balancing the memory resource requirements and trade-offs.
• If memory is not adequate, then build a prioritized list of memory-requiring processes and elements of the system. Assign memory to where the performance gains are the greatest. A prioritized list may look like the following:
1.
Operating System and RDBMS kernels (to include SGA and its components, buffer cache, and shared pool)
2.
User and application processes
For example, suppose you query Oracle Database dynamic performance tables and views and find that both the shared pool and database buffer cache require more memory. Then, assigning the limited spare memory to the shared pool may be more beneficial than assigning it to the database block buffer caches. These choices depend on the nature or shape of the database load.
The following IBM AIX on POWER Systems (64-bit) commands provide paging status and statistics:
• vmstat -s
• vmstat interval [repeats]
• sar -r interval [repeats]
C.1.4 Setting the Database Block Size
You can configure Oracle Database block size for better Input-Output throughput. On
IBM AIX on POWER Systems (64-bit), you can set the value of the
DB_BLOCK_SIZE initialization parameter to between 2 KB and 32 KB, with a default of 4 KB. If Oracle
Database is installed on a journaled file system, then the block size should be a multiple of the file system block size (4 KB on JFS, 16 KB to 1 MB on IBM Spectrum
Scale (GPFS)). For databases on raw partitions, Oracle Database block size is a multiple of the operating system physical block size (512 bytes on IBM AIX on
POWER Systems (64-bit)).
Oracle recommends smaller Oracle Database block sizes (2 KB or 4 KB) for online transaction processing or mixed workload environments and larger block sizes (8 KB,
16 KB, or 32 KB) for decision support system workload environments.
Administering Oracle Database on IBM AIX on POWER Systems (64-Bit) C-3
Disk Input-Output Issues
C.1.5 Tuning the Log Archive Buffers
By increasing the
LOG_BUFFER
size, you may be able to improve the speed of archiving the database, particularly if transactions are long or numerous. Monitor the log file Input-Output activity and system throughput to determine the optimum
LOG_BUFFER
size. Tune the
LOG_BUFFER
parameter carefully to ensure that the overall performance of normal database activity does not degrade.
For improved performance, create separate file systems for redo logs and control files
(or a single file system for both), with an agblksize
of 512 bytes rather than the default of 4 KB.
C.1.6 Input-Output Buffers and SQL*Loader
For high-speed data loading, such as using the SQL*Loader direct path option in addition to loading data in parallel, the CPU spends most of its time waiting for Input-
Output to complete. By increasing the number of buffers, you can maximize CPU usage, and by doing this, increase overall throughput.
The number of buffers (set by the SQL*Loader
BUFFERS
parameter) you choose depends on the amount of available memory and how much you want to maximize
CPU usage.
The performance gains depend on CPU usage and the degree of parallelism that you use when loading data.
C.2 Disk Input-Output Issues
Disk Input-Output contention can result from poor memory management (with subsequent paging and swapping), or poor distribution of tablespaces and files across disks.
Ensure that the Input-Output activity is distributed evenly across multiple disk drives by using IBM AIX on POWER Systems (64-bit) utilities such as filemon
, sar
, iostat
, and other performance tools to identify disks with high Input-Output activity.
This section contains the following topics:
•
IBM AIX on POWER Systems (64-Bit) Logical Volume Manager
(page C-4)
•
Using Journaled File Systems Compared to Raw Logical Volumes (page C-5)
•
Using Asynchronous Input-Output
(page C-7)
•
Input-Output Slaves (page C-7)
•
Using the DB_FILE_MULTIBLOCK_READ_COUNT Parameter
(page C-8)
•
Tuning Disk Input-Output Pacing
(page C-8)
•
Resilvering with Oracle Database
(page C-8)
C.2.1 IBM AIX on POWER Systems (64-Bit) Logical Volume Manager
The IBM AIX on POWER Systems (64-bit) Logical Volume Manager can stripe data across multiple disks to reduce disk contention. The primary objective of striping is to achieve high performance when reading and writing large sequential files. With improved storage subsystems, it is no longer recommended to use LVM striping.
C-4 Oracle Database Administrator's Reference
Disk Input-Output Issues
Oracle recommends to use the default striping by the storage subsystems. The operating system is no longer aware about where the data resides physically as the
LUNs presented to an AIX partition are logical and not physical.
C.2.2 Using Journaled File Systems Compared to Raw Logical Volumes
Address the following considerations when deciding whether to use journaled file systems or raw logical volumes:
• File systems are continually being improved, as are various file system implementations.
• Different vendors implement the file system layer in different ways to capitalize on the strengths of different disks. This makes it difficult to compare file systems across platforms.
• The Direct Input-Output and Concurrent Input-Output features included in IBM
AIX on POWER Systems (64-bit) improve file system performance to a level comparable to raw logical volumes.
• In earlier versions of IBM AIX on POWER Systems (64-bit), file systems supported only buffered read and write and added extra contention because of imperfect inode locking. These two issues are solved by the JFS2 Concurrent Input-Output feature and the Spectrum Scale (GPFS)Direct Input-Output feature.
• The introduction of more powerful Logical Volume Manager interfaces substantially reduces the tasks of configuring and backing up logical disks based on raw logical volumes.
• Oracle ASM works best when you add raw disk devices to disk groups. If you are using Oracle ASM, then do not use Logical Volume Manager for striping. Oracle
ASM implements striping and mirroring.
Note:
To use the Oracle RAC option, you must place data files on an Oracle ASM disk group or on a Spectrum Scale (GPFS) file system. You cannot use JFS or
JFS2. Direct Input-Output is implicitly enabled when you use Spectrum Scale
(GPFS).
File System Options
IBM AIX on POWER Systems (64-bit) includes Direct Input-Output and Concurrent
Input-Output support. Direct Input-Output and Concurrent Input-Output support enables database files to exist on file systems while bypassing the operating system buffer cache and removing inode locking operations that are redundant with the features provided by Oracle Database.
The following table lists file systems available on IBM AIX on POWER Systems (64-bit) and the recommended setting:
File System Option
JFS dio
Description
Concurrent Input-Output is not available on JFS. Direct
Input-Output is available, but performance is degraded compared to JFS2 with Concurrent Input-Output.
Administering Oracle Database on IBM AIX on POWER Systems (64-Bit) C-5
Disk Input-Output Issues
File System Option
JFS large file none
JFS2 cio
Spectrum
Scale (GPFS)
NA
Description
Oracle does not recommend using JFS large file for Oracle
Database because its 128 KB alignment constraint prevents you from using Direct Input-Output.
Concurrent Input-Output is a better setting than Direct Input-
Output on JFS2, because it provides support for multiple concurrent readers and writers on the same file. However, due to IBM AIX on POWER Systems (64-bit) restrictions on
JFS2/CIO, Concurrent Input-Output is intended to be used only with Oracle data files, control files, and log files. It should be applied only to file systems that are dedicated to such a purpose. For the same reason, the Oracle home directory is not supported on a JFS2 file system mounted with the
CIO
option. For example, during installation, if you inadvertently specify that the Oracle home directory is on a
JFS2 file system mounted with the
CIO
option, then while trying to relink Oracle, you may encounter the following error:
"ld: 0711-866 INTERNAL ERROR: Output symbol table size miscalculated"
Note
: For Oracle Database 11g Release 2 (11.2.0.2) and later, on IBM AIX on POWER Systems (64-bit) 6.1 systems and newer, Oracle recommends that you do not use the
CIO mount option on a JFS2 file system. For the latest Oracle
Database releases, it is not necessary to use the
CIO
mount option because, Oracle opens the filesystem with the
O_CIOR option internally. This gives the benefits of
CIO
while allowing other applications to open the Oracle data files in read only mode without the
O_CIO
option.
Oracle Database silently enables Direct Input-Output on
Spectrum Scale for optimum performance. Spectrum Scale
Direct Input-Output already supports multiple readers and writers on multiple nodes. Therefore, Direct Input-Output and Concurrent Input-Output are the same thing on
Spectrum Scale.
Considerations for JFS and JFS2
If you are placing Oracle Database logs on a JFS2 file system, then the optimal configuration is to create the file system using the agblksize=512
option and to mount it with the
CIO
option.
Before Oracle Database 12c, Direct Input-Output and Concurrent Input-Output could not be enabled at the file level on JFS/JFS2. Therefore, the Oracle home directory and data files had to be placed in separate file systems for optimal performance. The
Oracle home directory was placed on a file system mounted with default options, with the data files and logs on file systems mounted using the
DIO
or
CIO
options.
With Oracle Database 12c, you can enable Direct Input-Output and Concurrent Input-
Output on JFS/JFS2 at the file level. You can do this by setting the
FILESYSTEMIO_OPTIONS
parameter in the server parameter file to
SETALL
or
DIRECTIO
. This enables Concurrent Input-Output on JFS2 and Direct Input-Output on JFS for all data file Input-Output. Because the
DIRECTIO
setting disables asynchronous Input-Output it should normally not be used. As a result of this 12c feature, you can place data files on the same JFS/JFS2 file system as the Oracle home
C-6 Oracle Database Administrator's Reference
Disk Input-Output Issues directory and still use Direct Input-Output or Concurrent Input-Output for improved performance. As mentioned earlier, you should still place Oracle Database logs on a separate JFS2 file system for optimal performance.
See Also:
Oracle Architecture and Tuning on AIX v2.30
for more information
Considerations for Spectrum Scale
If you are using Spectrum Scale (GPFS), then you can use the same file system for all purposes. This includes using it for the Oracle home directory and for storing data files and logs. For optimal performance, you should use a large Spectrum Scale block size (typically, at least 512 KB). Spectrum Scale is designed for scalability, and there is no requirement to create multiple Spectrum Scale file systems as long as the amount of data fits in a single Spectrum Scale file system.
C.2.3 Using Asynchronous Input-Output
Oracle Database takes full advantage of asynchronous Input-Output provided by IBM
AIX on POWER Systems (64-bit), resulting in faster database access.
IBM AIX on POWER Systems (64-bit) support asynchronous Input-Output for database files created on file system partitions. When using asynchronous Input-
Output on file systems, the kernel database processes ( aioserver
) control each request from the time a request is taken off the queue to the time it is completed. The number of aioserver
servers determines the number of asynchronous Input-Output requests that can be processed in the system concurrently. There is no need to adjust the AIO tunables as the defaults for AIO tunables have been significantly increased.
C.2.4 Input-Output Slaves
Input-Output Slaves are specialized Oracle processes that perform only Input-Output.
They are rarely used on IBM AIX on POWER Systems (64-bit), because asynchronous
Input-Output is the default and recommended way for Oracle to perform Input-
Output operations on IBM AIX on POWER Systems (64-bit). Input-Output Slaves are allocated from shared memory buffers. Input-Output Slaves use the initialization parameters listed in the following table:
Parameter
DISK_ASYNCH_IO
TAPE_ASYNCH_IO
BACKUP_TAPE_IO_SLAVES
DBWR_IO_SLAVES
DB_WRITER_PROCESSES
Range of Values
true
/ false true
/ false true
/ false
0 - 999
1-20
Default Value
true true false
0
1
Generally, you do not adjust the parameters in the preceding table. However, on large workloads, the database writer may become a bottleneck. If it does, then increase the value of
DB_WRITER_PROCESSES
. As a general rule, do not increase the number of database writer processes above one for each pair of CPUs in the system or partition.
There are times when you must turn off asynchronous I/O. For example, if instructed to do so by Oracle Support for debugging. You can use the
DISK_ASYNCH_IO
and
Administering Oracle Database on IBM AIX on POWER Systems (64-Bit) C-7
Disk Input-Output Issues
TAPE_ASYNCH_IO
parameters to switch off asynchronous I/O for disk or tape devices.
TAPE_ASYNCH_IO
support is only available when the Media Manager software supports it and for Recovery Manager, if
BACKUP_TAPE_IO_SLAVES
is true.
Set the
DBWR_IO_SLAVES
parameter to greater than 0 only if the
DISK_ASYNCH_IO parameter is set to false
. Otherwise, the database writer process becomes a bottleneck. In this case, the optimal value on IBM AIX on POWER Systems (64-bit) for the
DBWR_IO_SLAVES
parameter is 4.
C.2.5 Using the DB_FILE_MULTIBLOCK_READ_COUNT Parameter
When using Direct Input-Output or Concurrent Input-Output with Oracle Database
12c, the IBM AIX on POWER Systems (64-bit) file system does not perform any readahead on sequential scans. For this reason the
DB_FILE_MULTIBLOCK_READ_COUNT value in the server parameter file should be increased when Direct Input-Output or
Concurrent Input-Output is enabled on Oracle data files. The read ahead is performed by Oracle Database as specified by the
DB_FILE_MULTIBLOCK_READ_COUNT initialization parameter.
Setting a large value for the
DB_FILE_MULTIBLOCK_READ_COUNT
initialization parameter usually yields better Input-Output throughput on sequential scans. On IBM
AIX on POWER Systems (64-bit), this parameter ranges from 1 to 512, but using a value higher than 16 usually does not provide additional performance gain.
Set this parameter so that its value when multiplied by the value of the
DB_BLOCK_SIZE
parameter produces a number larger than the Logical Volume
Manager stripe size. Such a setting causes more disks to be used.
C.2.6 Tuning Disk Input-Output Pacing
Disk Input-Output pacing is an IBM AIX on POWER Systems (64-bit) mechanism that enables the system administrator to limit the number of pending Input-Output requests to a file. This prevents disk Input-Output intensive processes from saturating the CPU. Therefore, the response time of interactive and CPU-intensive processes does not deteriorate.
You can achieve disk Input-Output pacing by adjusting two system parameters: the high-water mark and the low-water mark. When a process writes to a file that already has a pending high-water mark Input-Output request, the process is put to sleep. The process wakes up when the number of outstanding Input-Output requests falls lower than or equals the low-water mark.
Starting from IBM AIX 6.1 version, the file systems and AIX I/O subsystem are modified to accommodate large surges of file system I/O. In addition to these changes, the default values for I/O pacing have been modified. The default values for
IBM AIX 6.1 version and earlier was 0 to no I/O pacing. The default values for IBM
AIX 6.1 version and later are as follows:
• minpout
=4096
• maxpout
=8193
C.2.7 Resilvering with Oracle Database
If you disable mirror write consistency for an Oracle data file allocated on a raw logical volume, then the Oracle Database crash recovery process uses resilvering to recover after a system failure. This resilvering process prevents database inconsistencies or corruption.
C-8 Oracle Database Administrator's Reference
CPU Scheduling and Process Priorities
During crash recovery, if a data file is allocated on a logical volume with multiple copies, then the resilvering process performs a checksum on the data blocks of all the copies. It then performs one of the following:
• If the data blocks in a copy have valid checksums, then the resilvering process uses that copy to update the copies that have invalid checksums.
• If all copies have blocks with invalid checksums, then the resilvering process rebuilds the blocks using information from the redo log file. It then writes the data file to the logical volume and updates all the copies.
On IBM AIX on POWER Systems (64-bit), the resilvering process works only for data files allocated on raw logical volumes for which mirror write consistency is disabled.
Resilvering is not required for data files on mirrored logical volumes with mirror write consistency enabled, because mirror write consistency ensures that all copies are synchronized.
If the system fails while you are upgrading an earlier release of Oracle Database that used data files on logical volumes for which mirror write consistency was disabled, then run the syncvg
command to synchronize the mirrored logical volume before starting Oracle Database. If you do not synchronize the mirrored logical volume before starting the database, then Oracle Database may read incorrect data from a logical volume copy.
Note:
If a disk drive fails, then resilvering does not occur. You must run the syncvg command before you can reactivate the logical volume.
Caution:
Oracle supports resilvering for data files only. Do not disable mirror write consistency for redo log files.
C.3 CPU Scheduling and Process Priorities
The CPU is another system component for which processes may contend. Although the IBM AIX on POWER Systems (64-bit) kernel allocates CPU effectively most of the time, many processes compete for CPU cycles. If the system has multiple CPU (SMP), then there may be different levels of contention on each CPU.
C.4 AIXTHREAD_SCOPE Environment Variable
Oracle recommends using IBM AIX 7.1 version and IBM AIX 6.1 default (system wide scope) setting of the
AIXTHREAD_SCOPE
environment variable to
S (1:1)
.
See Also:
Thread tuning
for additional information about thread tuning
C.5 Network Information Service external naming support
Network Information Service external naming adapter is supported on IBM AIX on
POWER Systems (64-bit). To configure and use Network Information Service external naming, refer to Oracle Database Net Services Administrator's Guide.
Administering Oracle Database on IBM AIX on POWER Systems (64-Bit) C-9
Configuring IBM Java Secure Socket Extension Provider with Oracle JDBC Thin Driver
C.6 Configuring IBM Java Secure Socket Extension Provider with Oracle
JDBC Thin Driver
IBM Java 1.6 SR 16 is shipped with Oracle Database 12c Release 1 (12.1). If you want to configure SSL on IBM JDK, then you may face the following issues:
• IBM JSSE does not support
SSLv2Hello
SSL protocol. However, it accepts the
SSLv2Hello
message from the client encapsulating
SSLv3
or
TLS1.0
hello message.
For SSL clients using Thin JDBC connectors, you must set oracle.net.ss1_version
system property to select
TLSv1
SSL protocol or
SSLv3
SSL protocol since
SSLv3
is not recommended anymore after the
POODLE security issue. System property recommendation is to set
TLSV1.0
,
TLSV1.1
, and
TLSV1.2
on recommending
SSLv3
, or the connection will fail.
• IBM JSSE does not allow anonymous ciphers
For SSL clients using anonymous ciphers, you must replace the Default Trust
Manager with a Custom Trust Manager that accepts anonymous ciphers.
See Also:
•
Padding Oracle On Downgraded Legacy Encryption (POODLE) security vulnerability
for more information
• IBM JSSE documentation for more information about creating and installing Custom Trust Manager
C-10 Oracle Database Administrator's Reference
D
Administering Oracle Database on HP-UX
This appendix provides information about administering Oracle Database on HP-UX.
It contains the following topics:
•
HP-UX Shared Memory Segments for an Oracle Instance (page D-1)
•
HP-UX SCHED_NOAGE Scheduling Policy (page D-2)
•
Lightweight Timer Implementation
(page D-3)
•
(page D-3)
•
Large Memory Allocations and Oracle Database Tuning (page D-8)
•
CPU_COUNT Initialization Parameter and HP-UX Dynamic Processor
(page D-10)
•
Network Information Service external naming support (page D-10)
•
Activating and Setting Expanded Host Names and Node Names (page D-10)
D.1 HP-UX Shared Memory Segments for an Oracle Instance
When an Oracle Database instance starts, it creates memory segments by dividing the shared memory allocated for creating the Oracle System Global Area (SGA) by the value of the HP-UX shmmax
kernel parameter. For example, if 64 GB of shared memory is allocated for a single Oracle instance and the value of the shmmax parameter is 1 GB, then Oracle Database creates 64 shared memory segments for that instance.
Performance degradation can occur when an Oracle instance creates multiple shared memory segments. This is because each shared memory segment receives a unique protection key when Oracle Database creates the instance. The number of protection keys available on the system architecture for HP-UX Itanium is 14.
If the Oracle instance creates more shared memory segments than the number of protection keys, then the HP-UX operating system displays protection key faults.
Oracle recommends that you set the shmmax
parameter value to the amount of available physical memory on the system. Doing this ensures that the entire shared memory for a single Oracle instance is assigned to one shared memory segment and the instance requires only one protection key.
To display the list of active shared memory segments on the system, run the following command:
$ ipcs -m
Administering Oracle Database on HP-UX D-1
HP-UX SCHED_NOAGE Scheduling Policy
If Oracle Database creates more segments for the instance than the number of protection keys, then increase the value of the shmmax
kernel parameter.
See Also:
Oracle Database Installation Guide
for more information about the recommended minimum kernel parameter values
D.2 HP-UX SCHED_NOAGE Scheduling Policy
On HP-UX, most processes use a time-sharing scheduling policy. Time sharing can have detrimental effects on Oracle performance by descheduling an Oracle process during critical operations, for example, when it is holding a latch. HP-UX has a modified scheduling policy, referred to as
SCHED_NOAGE
, that specifically addresses this issue. Unlike the normal time-sharing policy, a process scheduled using
SCHED_NOAGE
does not increase or decrease in priority, nor is it preempted.
This feature is suited to online transaction processing environments because online transaction processing environments can cause competition for critical resources. The use of the
SCHED_NOAGE
policy with Oracle Database can increase performance by 10 percent or more in online transaction processing environments.
The
SCHED_NOAGE
policy does not provide the same level of performance gains in decision support environments because there is less resource competition. Because each application and server environment is different, you should test and verify that the environment benefits from the
SCHED_NOAGE
policy. When using
SCHED_NOAGE
,
Oracle recommends that you exercise caution in assigning highest priority to Oracle processes. Assigning highest
SCHED_NOAGE
priority to Oracle processes can exhaust
CPU resources on the system, causing other user processes to stop responding.
D.2.1 Enabling SCHED_NOAGE for Oracle Database
To permit Oracle Database to use the
SCHED_NOAGE
scheduling policy, the OSDBA group (typically, the dba
group) must have the
RTSCHED
and
RTPRIO
privileges to change the scheduling policy and set the priority level for Oracle processes. To give the dba
group these privileges:
1.
Log in as the root
user.
2.
Using any text editor, open the
/etc/privgroup
file, or create it if necessary.
3.
Add or edit the following line, which begins with the name of the OSDBA group, specifying the privileges
RTPRIO
and
RTSCHED
that you want to grant to this group every time the system restarts: dba RTPRIO RTSCHED
4.
Save the file, and quit the text editor.
5.
Enter the following command to grant the privileges to the OSDBA group:
# /usr/sbin/setprivgrp -f /etc/privgroup
6.
Enter the following command to verify that the privileges are set correctly:
# /usr/bin/getprivgrp dba
D-2 Oracle Database Administrator's Reference
Lightweight Timer Implementation
Add the
HPUX_SCHED_NOAGE
initialization parameter to the parameter file for each instance, setting the parameter to an integer value to specify process priority levels.
The supported range of values is 178 to 255. Lower values represent higher priorities.
The default value of
HPUX_SCHED_NOAGE
initialization parameter is 178 for all Oracle processes. For LMS processes, this can be changed by setting the initialization parameter
_os_sched_high_priority
. If the parameter
_os_sched_high_priority
is between 31 and 2, LMS processes run with
SCHED_RR
at the set priority. If the parameter value is between 178 and 255, the processes run at the set value with
SCHED_NOAGE
. However, LMS does not run at priority level less than the value of
HPUX_SCHED_NOAGE
.
If the
HPUX_SCHED_NOAGE
parameter setting is out of range, then Oracle Database automatically sets the parameter to a permissible value and continues with the
SCHED_NOAGE
policy with the new value. It also generates a message in the alert_sid.log
file about the new setting. Whenever the highest priority is assigned to Oracle processes, either by the user or by automatic readjustment, Oracle Database generates a message in the alert_sid.log
file warning about the possibility of exhaustion of CPU resources on the system. Oracle recommends that you set the parameter to assign the priority level you want for Oracle processes.
See Also:
The HP-UX documentation, the rtsched
(1) man page, and the rtsched
(2) man page for more information about priority policies and priority ranges
D.3 Lightweight Timer Implementation
With Oracle Database 11g, you can collect run-time statistics always if the dynamic initialization parameter
STATISTICS_LEVEL
is set to
TYPICAL
(default) or
ALL
. This parameter setting implicitly sets the
TIMED_STATISTICS
initialization parameter to true
. Oracle Database on HP-UX systems uses the gethrtime()
system library call to calculate elapsed times during the collection of the statistics. The use of this lightweight system library call enables you to collect run-time statistics always while running an Oracle instance, without affecting performance.
This system library call can provide a performance improvement of up to 10 percent over an Oracle release that does not use the gethrtime()
system library call when the
TIMED_STATISTICS
initialization parameter is explicitly set to true
. In addition, there is no negative impact on the online transaction processing performance of an
Oracle Database while using the gethrtime()
system library call to collect run-time statistics always.
D.4 Asynchronous Input-Output
The asynchronous Input-Output pseudo-driver on HP-UX enables Oracle Database to perform Input-Output to raw disk partitions using an asynchronous method, resulting in less Input-Output overhead and higher throughput. You can use the asynchronous
Input-Output pseudo-driver on both HP-UX servers and workstations.
This section contains the following topics:
•
(page D-4)
•
Implementing Asynchronous Input-Output
(page D-4)
•
Verifying Asynchronous Input-Output (page D-7)
Administering Oracle Database on HP-UX D-3
Asynchronous Input-Output
•
Asynchronous Flag in SGA (page D-8)
D.4.1 Granting MLOCK Privilege
To permit Oracle Database to process asynchronous Input-Output operations, the
OSDBA group ( dba
) must have the
MLOCK
privilege. To give the dba
group the
MLOCK
privilege:
1.
Log in as the root
user.
2.
Using any text editor, open the
/etc/privgroup
file, or create it if necessary.
3.
Add or edit the following line, which begins with the name of the OSDBA group, specifying the privilege
MLOCK
:
Note:
You must use only one line to specify the privileges for a particular group in this file. If the file already contains a line for the dba
group, then add the
MLOCK
privilege on the same line.
dba RTPRIO RTSCHED MLOCK
4.
Save the file, and quit the text editor.
5.
Enter the following command to grant the privileges to the OSDBA group:
# /usr/sbin/setprivgrp -f /etc/privgroup
6.
Enter the following command to verify that the privileges are set correctly:
# /usr/bin/getprivgrp dba
D.4.2 Implementing Asynchronous Input-Output
To use asynchronous Input-Output on HP-UX, you must use an Automatic Storage
Management disk group that uses raw partitions as the storage option for database files.
See Also:
Oracle Database Installation Guide
for more information about configuring
Automatic Storage Management and raw logical volumes on HP-UX systems
Before you can implement asynchronous Input-Output with either storage option, you must use the System Administrator Management utility to configure the asynchronous disk driver into the HP-UX kernel.
D-4 Oracle Database Administrator's Reference
Asynchronous Input-Output
Note:
In Oracle Database 11g Release 1, you did not have to set
DISK_ASYNCH_IO parameter to
FALSE
on a file system. However, starting with Oracle Database
11g Release 2, if database uses file system for storing the database files, then ensure that you set initialization parameter
DISK_ASYNCH_IO
to
FALSE
. By default the value of
DISK_ASYNCH_IO
is
TRUE
.
The
DISK_ASYNCH_IO
parameter must be set to
TRUE
only when raw partitions are used for storing database files.
To add the asynchronous disk driver and configure the kernel by using the System
Administrator Management utility:
1.
Run the following command as the root
user:
# sam
2.
3.
4.
5.
Select the Kernel Configuration area.
Select the Drivers area.
Select the asynchronous disk driver ( asyncdsk
).
Select Actions, and then select Add Driver to Kernel.
6.
7.
8.
9.
Select List, and then select Configurable Parameters.
Select the
MAX_ASYNC_PORTS
parameter.
Select Action, and then select Modify Configurable Parameter.
Specify a new value for the parameter, using the following guidelines, and then click OK.
The
MAX_ASYNC_PORTS
parameter is a configurable HP-UX kernel parameter that controls the maximum number of processes that can open the
/dev/async file simultaneously.
The system displays an error message when a process tries to open the
/dev/ async
file after the maximum number of processes have opened the file. This error can reduce performance on systems with a large number of shadow processes or many parallel query slaves performing asynchronous Input-Output.
This error is not recorded. To avoid this error, estimate the highest likely number of processes that can access the
/dev/async
file and set the
MAX_ASYNC_PORTS parameter to this value.
10.
Select Actions, and then select Process a New Kernel.
11.
Select one of the following options, and then click OK:
•
Move Kernel Into Place and Shutdown System/Reboot Now
•
Do Not Move Kernel Into Place: Do Not Shutdown/Reboot Now
If you choose the second option, then the new kernel, vmunix_test
, and the system.SAM
configuration file used to create it, are both created in the
/stand/ build
directory.
Administering Oracle Database on HP-UX D-5
Asynchronous Input-Output
To enable asynchronous Input-Output operations using the HP-UX asynchronous device driver:
1.
Log in as the root
user.
2.
If
/dev/async
does not exist, use the following command to create it:
# /sbin/mknod /dev/async c 101 0x0
By default, the minor number is set to 0. The following table describes the various minor numbers for 8-bit that you can use to create a device file:
Minor number Description
0x0 This is the HP-UX default value for
/dev/async
.
0x4
0x100
0x104
Enable disc device timeouts to complete with an error code rather than retrying forever. This setting is necessary for application-level disc mirroring, so as to avoid the situation where the application waits forever for a failed disc device to be repaired. Oracle RDBMS users should enable this feature when Automatic Storage Management mirroring/replication (internal redundancy) is used. SGA will be locked in memory.
Enable on-demand locking of memory pages by async driver when asyncdsk_open(2) is called. A low-overhead routine is then used to lock a page into memory during I/O operations.
On-demand locking is critically important when using Oracle's
Automatic Memory Management feature (the use of
MEMORY_TARGET in the init.ora
file to control memory usage). RDBMS deployments utilizing dynamic nPar or dynamic vPar features should also configure on-demand locking.
More traditional RDBMS deployments can consider on-demand locking in light of its more obvious effects. Generally speaking, RDBMS startup will be quicker because the complete SGA is not locked into memory immediately. However, some instances will experience a slight runtime performance penalty with on-demand locking as memory pages are dynamically locked/unlocked for each I/O request.
This is a combination of 0x100 and 0x4. Both the features are enabled.
3.
Enter the following command to verify that the
/dev/async
device file exists and has the major number 101:
# ls -l /dev/async
The output of this command should look similar to the following: crw------- 1 oracle dba 101 0x000000 Oct 28 10:32 /dev/async
4.
If required, give the device file the operating system owner and permissions consistent with those of the Oracle software owner and OSDBA group.
If the Oracle software owner is oracle
and the OSDBA group is dba
, then run the following commands:
# /usr/bin/chown oracle:dba /dev/async
# /usr/bin/chmod 660 /dev/async
D-6 Oracle Database Administrator's Reference
Asynchronous Input-Output
D.4.3 Verifying Asynchronous Input-Output
To verify asynchronous Input-Output, first verify that the HP-UX asynchronous driver is configured for Oracle Database, then verify that Oracle Database is executing asynchronous Input-Output through the HP-UX device driver:
•
Verifying That HP-UX Asynchronous Driver is Configured for Oracle Database
(page D-7)
•
Verifying that Oracle Database is Using Asynchronous Input-Output
(page D-7)
D.4.3.1 Verifying That HP-UX Asynchronous Driver is Configured for Oracle Database
To verify that the HP-UX asynchronous driver is configured properly for Oracle
Database:
1.
Start Oracle Database with a few parallel query slave processes.
2.
Start the GlancePlus/UX utility as follows:
$ gpm
3.
In the main window, click Reports and then click Process List.
4.
In the Process List window, select one parallel query slave process, select Reports, and then select Process Open Files.
The list of files currently opened by the parallel query slave process is displayed.
5.
In the list of open files, check for the
/dev/async
file or the 101 0x104000 mode.
If either is in the list, then the
/dev/async
file has been opened by the parallel query slave process, and the HP-UX asynchronous device driver is configured properly to enable Oracle processes to run asynchronous Input-Output. Make a note of the file descriptor number for the
/dev/async
file.
D.4.3.2 Verifying that Oracle Database is Using Asynchronous Input-Output
To verify that Oracle Database is using asynchronous Input-Output through the HP-
UX asynchronous device driver:
1.
Attach the HP-UX tusc
utility to the same Oracle parallel query slave that you selected in GlancePlus in the preceding procedure.
2.
Run an Input-Output bound query in the environment.
3.
Check the pattern of read and write calls in the tusc
output.
You can do this, for example, by entering the following command, where
pid
is the process ID of a parallel query slave supposed to process asynchronous Input-
Output:
$ tusc -p pid > tusc.output
4.
After running the query, press Ctrl+c to disconnect from the process, and then open the tusc.output
file.
The following example shows a sample tusc.output
file:
( Attached to process 2052: "ora_p000_tpch" [ 64-bit ])
...................
Administering Oracle Database on HP-UX D-7
Large Memory Allocations and Oracle Database Tuning
........................
[2052] read(9, "80\0\001\013 \b\0\0\0\0\0\0\0\0".., 388) .. = 28
[2052] write(9, "\0\0\00e\0\0\0\080\0\001\013Ð \0".., 48) .. = 48
[2052] read(9, "80\0\001\013¢ 18\0\0\0\0\0\0\0\0".., 388) .. = 28
[2052] write(9, "\0\0\00e\0\0\0\080\0\001\01bd4\0".., 48) .. = 48
If the
DISK_ASYNCH_IO
initialization parameter is not explicitly set to false
(set to true
by default), then the tusc.output
file shows a pattern of asynchronous read/write calls of the same file descriptor (9 in the preceding example) back to back.
Map the file descriptor number in the tusc.output
file to that used by
/dev/ async
file in GlancePlus. They should match for the particular parallel query slave process. This verifies that Input-Output through the HP-UX asynchronous driver is asynchronous. With synchronous Input-Output, or if the
DISK_ASYNCH_IO initialization parameter is explicitly set to
FALSE
, you do not see the asynchronous read/write pattern described previously. Instead, you see calls to lseek
or pread
/ pwrite
. You also see many different file descriptors (the first argument to read/write) instead of just a single file descriptor.
D.4.4 Asynchronous Flag in SGA
Oracle Database on HP-UX uses a nonblocking polling facility provided by the HP-UX asynchronous driver to check the status of the Input-Output operations. This polling is performed by checking a flag that is updated by the asynchronous driver based on the status of the Input-Output operations submitted. HP-UX requires that this flag be in shared memory.
Oracle Database configures an asynchronous flag in the SGA for each Oracle process.
Oracle Database on HP-UX has a true asynchronous Input-Output mechanism where
Input-Output requests can be issued even though some previously issued Input-
Output operations are not complete. This helps to enhance performance and ensures good scalability of parallel Input-Output processes.
Releases of Oracle Database earlier than release 8.1.7 were able to run Input-Output operations only from shared memory by using the HP-UX asynchronous driver.
Oracle Database 11g runs Input-Output operations from both shared memory and process-private regions using the new HP-UX asynchronous driver. However, Input-
Output operations through the asynchronous driver are not asynchronous in nature.
This is because Oracle Database must perform a blocking wait to check the status of
Input-Output operations submitted to the asynchronous driver. This causes some
Oracle processes, such as the database writer process, to essentially process synchronous Input-Output.
D.5 Large Memory Allocations and Oracle Database Tuning
Applications running on Oracle Database 11g and later can use significantly more memory than applications running on earlier releases. This is because Oracle Database
11g changes the default setting for virtual memory data pages from D (4 KB) to L (4
GB) on HP-UX systems.
This section contains the following topics:
•
Default Large Virtual Memory Page Size
(page D-9)
•
Tuning Recommendations (page D-9)
D-8 Oracle Database Administrator's Reference
Large Memory Allocations and Oracle Database Tuning
•
Tunable Base Page Size (page D-10)
D.5.1 Default Large Virtual Memory Page Size
By default, Oracle Database uses the largest virtual memory page size setting available on HP-UX for allocating process-private memory. It is defined by the value
L
(largest.)
This value is set as one of the
LARGE_PAGE_FLAGS
options when linking an Oracle executable.
When the virtual memory page size is set to L, HP-UX allocates the available processprivate memory to pages of 1 MB, 4 MB, 16 MB and so on, until it reaches the 1 GB limit, or until it reaches the total amount of allocated memory. If you allocate enough memory to the Oracle PGA for the operating system to be able to allocate memory in larger data page size units, then the operating system allocates the maximum page size at once. For example, if you allocate 48 MB for the Oracle PGA, then the system can have either 3 pages each of 16 MB, or a series of pages in unit sizes with the smaller multiples. For example, four 1 MB pages, three 4 MB pages, and two 16 MB pages. If you allocate 64 MB to the PGA, then the operating system allocates one page of 64 MB, as the data page unit size matches the available memory.
In general, large memory pages yield better application performance by reducing the number of virtual memory translation faults that must be handled by the operating system, freeing more CPU resources for the application. Large pages help to reduce the total number of data pages required to allocate the process-private memory. This reduction decreases the chances of translation lookaside buffer misses at the processor level.
However, if applications are constrained in memory and tend to run a very large number of processes, then this drastic page size increase may lead processes to indicate large memory allocations, followed by an
Out of memory
error message. If this happens, then you must lower the page size to a value between the D (default) size of 4 KB and the
L
(largest) size of 4 GB.
With the lowest page size setting (4 KB), CPU utilization can be 20 percent higher than that with a larger page size setting. With the highest setting of
L
, the memory utilization can be 50 percent higher than that with a 4 MB setting. In cases where the system shows memory constraints, Oracle recommends that you set the page size to match the requirements of the particular application, within the constraints of available memory resources.
For example, an application that has problems with the
L
setting may show reasonable performance with a 4 MB virtual memory page setting.
D.5.2 Tuning Recommendations
To address tuning for the increased memory allocation required for persistent private
SQL areas and large virtual memory page sizes, Oracle recommends that you decrease the virtual memory data page size for Oracle Database as required. Use the following command to alter the page size setting:
# /usr/bin/chatr +pd newsize $ORACLE_HOME/bin/oracle
In the preceding example,
newsize
represents the new value of the virtual memory page size.
Display the new setting using the chatr
command as follows:
# /usr/bin/chatr $ORACLE_HOME/bin/oracle
Administering Oracle Database on HP-UX D-9
CPU_COUNT Initialization Parameter and HP-UX Dynamic Processor Reconfiguration
D.5.3 Tunable Base Page Size
A large base page size enables efficient memory management. The default value for base_pagesize
is 4 KB. The new feature introduced with HP-UX 11.31 enables to adjust the size of the base page, by invoking kctune
(1 M) to change the tunable base_pagesize
and then restart the computer.
D.6 CPU_COUNT Initialization Parameter and HP-UX Dynamic Processor
Reconfiguration
HP-UX 11i supports dynamic run-time reconfiguration of processor sets and dynamic reassignment of workload between processor sets by valid users.
HP-UX Virtual Partitions enable users to configure their systems in multiple logical partitions where each partition is assigned its own set of processors, memory, and
Input-Output resources, and can run a separate instance of the HP-UX operating system. HP-UX processor sets integrated with vPars support dynamic processor migration from one virtual partition to another without requiring a restart of any virtual partition. This helps to provide efficient resource partitioning between applications to minimize interference and guarantees necessary resource allocation to each application running on the HP-UX server.
See Also:
Refer to Oracle Database Concepts for more information about dynamic resource provisioning
D.7 Network Information Service external naming support
Network Information Service external naming adapter is supported on HP-UX.
See Also:
Oracle Database Net Services Administrator's Guide
to configure and use Network Information Service external naming
D.8 Activating and Setting Expanded Host Names and Node Names
The system node names and host names have default length limits of 8 and 64 bytes.
The system administrator can configure the system to expand both these limits to 255 bytes.
A dynamic kernel tunable parameter expanded_node_host_names
, must be turned on to allow larger names to be set.
To turn on the kernel parameter, run the following command: kctune expanded_node_host_names=1
To turn off the kernel parameter, run the following command: kctune expanded_node_host_names=0
D-10 Oracle Database Administrator's Reference
E
Using Oracle ODBC Driver
This appendix provides information related to using Oracle ODBC Driver.
It contains the following sections:
•
Oracle ODBC Features Not Supported (page E-1)
•
Implementation of Data Types (page E-2)
•
Limitations on Data Types (page E-2)
•
Format of the Connection String for the SQLDriverConnect Function (page E-3)
•
Reducing Lock Timeout in a Program
(page E-5)
•
Linking ODBC Applications (page E-5)
•
Obtaining Information About ROWIDs (page E-6)
•
(page E-6)
•
(page E-6)
•
Enabling EXEC Syntax (page E-12)
•
(page E-13)
•
•
Performance and Tuning (page E-22)
•
(page E-25)
See Also:
Oracle Database Installation Guide
for your respective platform for the ODBC driver certification information
E.1 Oracle ODBC Features Not Supported
Oracle ODBC Driver does not support the following Oracle ODBC 3.0 features:
• Interval data types
•
SQL_C_UBIGINT
and
SQL_C_SBIGINT
C data type identifiers
• Shared connections
• Shared environments
Using Oracle ODBC Driver E-1
Implementation of Data Types
• The
SQL_LOGIN_TIMEOUT
attribute of
SQLSetConnectAttr
• The expired password option
Oracle ODBC Driver does not support the SQL functions listed in the following table:
String Functions
BIT_LENGTH
CHAR_LENGTH
CHARACTER_LENGTH
DIFFERENCE
OCTET_LENGTH
POSITION
Numeric Functions
ACOS
ASIN
ATAN
ATAN2
COT
DEGREES
RADIANS
RAND
ROUND
Time, Date, and Interval Functions
CURRENT_DATE
CURRENT_TIME
CURRENT_TIMESTAMP
EXTRACT
TIMESTAMPDIFF
E.2 Implementation of Data Types
This section discusses the
DATE
,
TIMESTAMP
, and floating point data types.
DATE and TIMESTAMP
The semantics of Oracle
DATE
and
TIMESTAMP
data types do not correspond exactly with the ODBC data types with the same names. The Oracle
DATE
data type contains both date and time information. The
SQL_DATE
data type contains only date information. The Oracle
TIMESTAMP
data type also contains date and time information, but it has greater precision in fractional seconds. Oracle ODBC Driver reports the data types of both Oracle
DATE
and
TIMESTAMP
columns as
SQL_TIMESTAMP
to prevent information loss. Similarly, Oracle ODBC Driver binds
SQL_TIMESTAMP
parameters as Oracle
TIMESTAMP
values.
See Also:
"
DATE and TIMESTAMP Data Types (page E-24)" for information about
DATE
and
TIMESTAMP
data types related to performance and tuning
Floating Point Data Types
When connected to an Oracle Database 12c Release 2 (12.2) or later, Oracle ODBC
Driver maps the Oracle floating point data types
BINARY_FLOAT
and
BINARY_DOUBLE
to the ODBC data types
SQL_REAL
and
SQL_DOUBLE
, respectively.
In earlier releases,
SQL_REAL
and
SQL_DOUBLE
mapped to the generic Oracle numeric data type.
E.3 Limitations on Data Types
Oracle ODBC Driver and Oracle Database impose limitations on data types. The following table describes these limitations:
E-2 Oracle Database Administrator's Reference
Format of the Connection String for the SQLDriverConnect Function
Limited Data Type
Literals
SQL_LONGVARCHAR
and
SQL_WLONGVARCHAR
SQL_LONGVARCHAR
and
SQL_LONGVARBINARY
Description
Oracle Database limits literals in SQL statements to 4000 bytes.
The Oracle limit for
SQL_LONGVARCHAR
data, where the column type is
LONG
, is 2,147,483,647 bytes. The Oracle limit for
SQL_LONGVARCHAR
data, where the column type is
CLOB
, is 4 gigabytes. The limiting factor is the client workstation memory.
Oracle Database permits only a single long data column in each table. The long data types are
SQL_LONGVARCHAR
(
LONG
) and
SQL_LONGVARBINARY
(
LONG RAW
). Oracle recommends that you use
CLOB
and
BLOB
columns instead. There is no restriction on the number of
CLOB
and
BLOB
columns in a table.
E.4 Format of the Connection String for the SQLDriverConnect Function
The
SQLDriverConnect
function is one of the functions implemented by Oracle
ODBC Driver. The following table describes the keywords that you can include in the connection string argument of the
SQLDriverConnect
function call:
Keyword
DSN
DBQ
UID
PWD
DBA
APA
RST
Meaning
ODBC data source name
TNS service name
User ID or user name
Password
Database attribute
Applications attributes
Result sets
Value
User-supplied name
This is a mandatory keyword.
User-supplied name
This is a mandatory keyword.
User-supplied name
This is a mandatory keyword.
User-supplied name
Specify
PWD=;
for an empty password.
This is a mandatory keyword.
W
implies write access
R
implies read-only access
T
implies that thread safety is to be enabled.
F
implies that thread safety is to be disabled.
T
implies that result sets are to be enabled.
F
implies that result sets are to be disabled.
Using Oracle ODBC Driver E-3
Format of the Connection String for the SQLDriverConnect Function
FRC
FDL
LOB
FWC
FBS
FEN
EXC
Keyword
QTO
CSR
BAM
Meaning
Query timeout option
Close cursor
Batch autocommit mode
Fetch buffer size
Failover
Failover retry count
Failover delay
LOB writes
Force
SQL_WCHAR
support
EXEC
syntax
Value
T
implies that query timeout is to be enabled.
F
implies that query timeout is to be disabled.
T
implies that close cursor is to be enabled.
F
implies that close cursor is to be disabled.
IfAllSuccessful
implies commit only if all statements are successful (old behavior).
UpToFirstFailure
implies commit up to first failing statement. This is ODBC version 7 behavior.
AllSuccessful
implies commit all successful statements.
User-supplied numeric value
(specify a value in bytes of 0 or greater).The default is
60,000 bytes.
T
implies failover is to be enabled.
F
implies failover is to be disabled.
User-supplied numeric value.
The default is 10.
User-supplied numeric value.
The default is 10.
T
implies LOBs are to be enabled.
F
implies LOBs are to be disabled.
T
implies
Force
SQL_WCHAR
is to be enabled.
F
implies
Force
SQL_WCHAR
is to be disabled.
T
implies
EXEC
syntax is to be enabled.
F
implies
EXEC
syntax is to be disabled.
E-4 Oracle Database Administrator's Reference
Reducing Lock Timeout in a Program
Keyword
XSM
MDI
DPM
BTD
NUM
Meaning
Schema field
Value
Default
implies that the default value is to be used.
Database
implies that the database name is to be used.
Owner
implies that the name of the owner is to be used.
Set metadata ID default
T
implies that the default value of
SQL_ATTR_METADATA_ID
is
SQL_TRUE
.
F
implies that the default value of
SQL_ATTR_METADATA_ID
is
SQL_FALSE
.
Disable
SQLDescribeParam T
implies that
SQLDescribeParam
is to be disabled.
F
implies that
SQLDescribeParam
is to be enabled.
Bind
TIMESTAMP
as
DATE
Numeric settings
T
implies that
SQL_TIMESTAMP
is to be bound as Oracle
DATE
.
F
implies that
SQL_TIMESTAMP
is to be bound as Oracle
TIMESTAMP
.
NLS
implies that the
Globalization Support numeric settings are to be used (to determine the decimal and group separator).
E.5 Reducing Lock Timeout in a Program
Oracle Database waits indefinitely for lock conflicts between transactions to be resolved. However, you can limit the amount of time that Oracle Database waits for locks to be resolved. To do this, set the
SQL_ATTR_QUERY_TIMEOUT
attribute of the
ODBC
SQLSetStmtAttr
function while calling this function before connecting to the data source.
E.6 Linking ODBC Applications
When you link the program, you must link it with the Driver Manager library, libodbc.so
.
Using Oracle ODBC Driver E-5
Obtaining Information About ROWIDs
E.7 Obtaining Information About ROWIDs
The ODBC
SQLSpecialColumns
function returns information about the columns in a table. When used with Oracle ODBC Driver, it returns information about the Oracle
ROWIDs associated with an Oracle table.
E.8 ROWIDs in a WHERE Clause
ROWIDs may be used in the
WHERE
clause of an SQL statement. However, the ROWID value must be presented in a parameter marker.
E.9 Enabling Result Sets
Oracle reference cursors, also known as result sets, enable an application to retrieve data using stored procedures and stored functions. The following information describes how to use reference cursors to enable result sets through ODBC:
• You must use the ODBC syntax for calling stored procedures. Native PL/SQL is not supported through ODBC. The following code sample identifies how to call the procedure or function without a package and within a package. The package name in this case is
RSET
.
Procedure call:
{CALL Example1(?)}
{CALL RSET.Example1(?)}
Function Call:
{? = CALL Example1(?)}
{? = CALL RSET.Example1(?)}
• The PL/SQL reference cursor parameters are omitted when calling the procedure.
For example, assume procedure
Example2
is defined to have four parameters.
Parameters 1 and 3 are reference cursor parameters and parameters 2 and 4 are character strings. The call is specified as:
{CALL RSET.Example2("Literal 1", "Literal 2")}
The following sample application shows how to return a result set by using Oracle
ODBC Driver:
/*
* Sample Application using Oracle reference cursors through ODBC
*
* Assumptions:
*
* 1) Oracle Sample database is present with data loaded for the EMP table.
*
* 2) Two fields are referenced from the EMP table, ename and mgr.
*
* 3) A data source has been setup to access the sample database.
*
*
* Program Description:
*
* Abstract:
*
* This program demonstrates how to return result sets using
* Oracle stored procedures
*
* Details:
E-6 Oracle Database Administrator's Reference
Enabling Result Sets
*
* This program:
* Creates an ODBC connection to the database.
* Creates a Packaged Procedure containing two result sets.
* Executes the procedure and retrieves the data from both result sets.
* Displays the data to the user.
* Deletes the package then logs the user out of the database.
*
*
* The following is the actual PL/SQL this code generates to
* create the stored procedures.
*
DROP PACKAGE ODBCRefCur;
CREATE PACKAGE ODBCRefCur AS
TYPE ename_cur IS REF CURSOR;
TYPE mgr_cur IS REF CURSOR;
PROCEDURE EmpCurs(Ename IN OUT ename_cur, Mgr IN OUT mgr_cur, pjob IN VARCHAR2);
END;
/
CREATE PACKAGE BODY ODBCRefCur AS
PROCEDURE EmpCurs(Ename IN OUT ename_cur, Mgr IN OUT mgr_cur, pjob IN VARCHAR2)
AS
BEGIN
IF NOT Ename%ISOPEN
THEN
OPEN Ename for SELECT ename from emp;
END IF;
IF NOT Mgr%ISOPEN
THEN
OPEN Mgr for SELECT mgr from emp where job = pjob;
END IF;
END;
END;
/
*
* End PL/SQL for Reference Cursor.
*/
/*
* Include Files
*/
#include <stdio.h>
#include <sql.h>
#include <sqlext.h>
/*
* Defines
*/
#define JOB_LEN 9
#define DATA_LEN 100
#define SQL_STMT_LEN 500
/*
* Procedures
*/ void DisplayError( SWORD HandleType, SQLHANDLE hHandle, char *Module );
/*
* Main Program
Using Oracle ODBC Driver E-7
Enabling Result Sets
*/ int main()
{
SQLHENV hEnv;
SQLHDBC hDbc;
SQLHSTMT hStmt;
SQLRETURN rc; char *DefUserName ="jones"; char *DefPassWord ="password";
SQLCHAR ServerName[DATA_LEN];
SQLCHAR *pServerName=ServerName;
SQLCHAR UserName[DATA_LEN];
SQLCHAR *pUserName=UserName;
SQLCHAR PassWord[DATA_LEN];
SQLCHAR *pPassWord=PassWord; char Data[DATA_LEN];
SQLINTEGER DataLen; char error[DATA_LEN]; char *charptr;
SQLCHAR SqlStmt[SQL_STMT_LEN];
SQLCHAR *pSqlStmt=SqlStmt; char *pSalesMan = "SALESMAN";
SQLINTEGER sqlnts=SQL_NTS;
/*
* Allocate the Environment Handle
*/ rc = SQLAllocHandle( SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hEnv ); if (rc != SQL_SUCCESS)
{
printf( "Cannot Allocate Environment Handle\n");
printf( "\nHit Return to Exit\n");
charptr = gets ((char *)error);
exit(1);
}
/*
* Set the ODBC Version
*/ rc = SQLSetEnvAttr( hEnv,SQL_ATTR_ODBC_VERSION,(void *)SQL_OV_ODBC3,0); if (rc != SQL_SUCCESS)
{
printf( "Cannot Set ODBC Version\n");
printf( "\nHit Return to Exit\n");
charptr = gets ((char *)error);
exit(1);
}
/*
* Allocate the Connection handle
*/ rc = SQLAllocHandle( SQL_HANDLE_DBC, hEnv, &hDbc ); if (rc != SQL_SUCCESS)
{
printf( "Cannot Allocate Connection Handle\n");
printf( "\nHit Return to Exit\n");
charptr = gets ((char *)error);
exit(1);
}
/*
* Get User Information
*/ strcpy ((char *) pUserName, DefUserName ); strcpy ((char *) pPassWord, DefPassWord );
E-8 Oracle Database Administrator's Reference
Enabling Result Sets
/*
* Data Source name
*/ printf( "\nEnter the ODBC Data Source Name\n" ); charptr = gets ((char *) ServerName);
/*
* User Name
*/ printf ( "\nEnter User Name Default [%s]\n", pUserName); charptr = gets ((char *) UserName); if (*charptr == '\0')
{
strcpy ((char *) pUserName, (char *) DefUserName );
}
/*
* Password
*/ printf ( "\nEnter Password Default [%s]\n", pPassWord); charptr = gets ((char *)PassWord); if (*charptr == '\0')
{
strcpy ((char *) pPassWord, (char *) DefPassWord );
}
/*
* Connection to the database
*/ rc = SQLConnect( hDbc,pServerName,(SQLSMALLINT) strlen((char
*)pServerName),pUserName,(SQLSMALLINT) strlen((char *)pUserName),pPassWord,
(SQLSMALLINT) strlen((char *)pPassWord)); if (rc != SQL_SUCCESS)
{
DisplayError(SQL_HANDLE_DBC, hDbc, "SQLConnect");
}
/*
* Allocate a Statement
*/ rc = SQLAllocHandle( SQL_HANDLE_STMT, hDbc, &hStmt ); if (rc != SQL_SUCCESS)
{
printf( "Cannot Allocate Statement Handle\n");
printf( "\nHit Return to Exit\n");
charptr = gets ((char *)error);
exit(1);
}
/*
* Drop the Package
*/ strcpy( (char *) pSqlStmt, "DROP PACKAGE ODBCRefCur"); rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt));
/*
* Create the Package Header
*/ strcpy( (char *) pSqlStmt, "CREATE PACKAGE ODBCRefCur AS\n"); strcat( (char *) pSqlStmt, " TYPE ename_cur IS REF CURSOR;\n"); strcat( (char *) pSqlStmt, " TYPE mgr_cur IS REF CURSOR;\n\n"); strcat( (char *) pSqlStmt, " PROCEDURE EmpCurs (Ename IN OUT ename_cur,"); strcat( (char *) pSqlStmt, "Mgr IN OUT mgr_cur,pjob IN VARCHAR2);\n\n"); strcat( (char *) pSqlStmt, "END;\n"); rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt)); if (rc != SQL_SUCCESS)
{
Using Oracle ODBC Driver E-9
Enabling Result Sets
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLExecDirect");
}
/*
* Create the Package Body
*/ strcpy( (char *) pSqlStmt, "CREATE PACKAGE BODY ODBCRefCur AS\n"); strcat( (char *) pSqlStmt, " PROCEDURE EmpCurs (Ename IN OUT ename_cur,"); strcat( (char *) pSqlStmt, "Mgr IN OUT mgr_cur, pjob IN VARCHAR2)\n AS\n BEGIN\n"); strcat( (char *) pSqlStmt, " IF NOT Ename%ISOPEN\n THEN\n"); strcat( (char *) pSqlStmt, " OPEN Ename for SELECT ename from emp;\n"); strcat( (char *) pSqlStmt, " END IF;\n\n"); strcat( (char *) pSqlStmt, " IF NOT Mgr%ISOPEN\n THEN\n"); strcat( (char *) pSqlStmt, " OPEN Mgr for SELECT mgr from emp where job = pjob;\n"); strcat( (char *) pSqlStmt, " END IF;\n"); strcat( (char *) pSqlStmt, " END;\n"); strcat( (char *) pSqlStmt, "END;\n"); rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt)); if (rc != SQL_SUCCESS)
{
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLExecDirect");
}
/*
* Bind the Parameter
*/ rc = SQLBindParameter(hStmt,1,SQL_PARAM_INPUT,SQL_C_CHAR,SQL_CHAR,JOB_LEN,
0,pSalesMan,0,&sqlnts);
/*
* Call the Store Procedure which executes the Result Sets
*/ strcpy( (char *) pSqlStmt, "{CALL ODBCRefCur.EmpCurs(?)}"); rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt)); if (rc != SQL_SUCCESS)
{
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLExecDirect");
}
/*
* Bind the Data
*/ rc = SQLBindCol( hStmt,1,SQL_C_CHAR,Data,sizeof(Data),&DataLen); if (rc != SQL_SUCCESS)
{
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLBindCol");
}
/*
* Get the data for Result Set 1
*/ printf( "\nEmployee Names\n\n"); while ( rc == SQL_SUCCESS )
{
rc = SQLFetch( hStmt );
if ( rc == SQL_SUCCESS )
{
printf("%s\n", Data);
}
else
{
if (rc != SQL_NO_DATA)
{
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLFetch");
}
}
E-10 Oracle Database Administrator's Reference
} printf( "\nFirst Result Set - Hit Return to Continue\n"); charptr = gets ((char *)error);
/*
* Get the Next Result Set
*/ rc = SQLMoreResults( hStmt ); if (rc != SQL_SUCCESS)
{
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLMoreResults");
}
/*
* Get the data for Result Set 2
*/ printf( "\nManagers\n\n"); while ( rc == SQL_SUCCESS )
{
rc = SQLFetch( hStmt );
if ( rc == SQL_SUCCESS )
{
printf("%s\n", Data);
}
else
{
if (rc != SQL_NO_DATA)
{
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLFetch");
}
}
} printf( "\nSecond Result Set - Hit Return to Continue\n"); charptr = gets ((char *)error);
/*
* Should Be No More Results Sets
*/ rc = SQLMoreResults( hStmt ); if (rc != SQL_NO_DATA)
{
DisplayError(SQL_HANDLE_STMT, hStmt, "SQLMoreResults");
}
/*
* Drop the Package
*/ strcpy( (char *) pSqlStmt, "DROP PACKAGE ODBCRefCur"); rc = SQLExecDirect(hStmt, pSqlStmt, strlen((char *)pSqlStmt));
/*
* Free handles close connections to the database
*/
SQLFreeHandle( SQL_HANDLE_STMT, hStmt );
SQLDisconnect( hDbc );
SQLFreeHandle( SQL_HANDLE_DBC, hDbc );
SQLFreeHandle( SQL_HANDLE_ENV, hEnv ); printf( "\nAll Done - Hit Return to Exit\n"); charptr = gets ((char *)error); return(0);
}
/*
* Display Error Messages
*/ void DisplayError( SWORD HandleType, SQLHANDLE hHandle, char *Module )
{
Enabling Result Sets
Using Oracle ODBC Driver E-11
Enabling EXEC Syntax
SQLCHAR MessageText[255];
SQLCHAR SQLState[80];
SQLRETURN rc=SQL_SUCCESS; long NativeError;
SWORD RetLen;
SQLCHAR error[25]; char *charptr; rc =
SQLGetDiagRec(HandleType,hHandle,1,SQLState,&NativeError,MessageText,255,&RetLen); printf( "Failure Calling %s\n", Module ); if (rc == SQL_SUCCESS || rc == SQL_SUCCESS_WITH_INFO)
{
printf( "\t\t\t State: %s\n", SQLState);
printf( "\t\t\t Native Error: %d\n", NativeError );
printf( "\t\t\t Error Message: %s\n", MessageText );
} printf( "\nHit Return to Exit\n"); charptr = gets ((char *)error); exit(1);
}
E.10 Enabling EXEC Syntax
If the syntax of the SQL Server
EXEC
statement can be readily translated to an equivalent Oracle procedure call without requiring any change to it, then Oracle
ODBC Driver can translate it if you enable this option.
The complete name of a SQL Server procedure consists of up to four identifiers:
• Server name
• Database name
• Owner name
• Procedure name
The format for the name is:
[[[server.][database].][owner_name].]procedure_name
During the migration of Microsoft SQL Server database to Oracle Database, the definition of each SQL Server procedure or function is converted to its equivalent
Oracle Database syntax and is defined in a schema in Oracle Database. Migrated procedures are often reorganized (and created in schemas) in one of the following ways:
• All procedures are migrated to one schema (the default option).
• All procedures defined in one SQL Server database are migrated to the schema named with that database name.
• All procedures owned by one user are migrated to the schema named with that user's name.
To support these three ways of organizing migrated procedures, you can specify one of these schema name options for translating procedure names. Object names in the translated Oracle procedure call are not case-sensitive.
E-12 Oracle Database Administrator's Reference
Supported Functionality
E.11 Supported Functionality
This section provides information about the functionality supported by Oracle ODBC
Driver. It contains the following sections:
•
(page E-13)
•
Implementation of ODBC API Functions (page E-13)
•
Implementation of the ODBC SQL Syntax
(page E-14)
•
Implementation of Data Types (page E-14)
E.11.1 API Conformance
Oracle ODBC Driver release 10.2.0.1.0 and higher supports all Core, Level 2, and Level
1 functions.
E.11.2 Implementation of ODBC API Functions
The following table describes how Oracle ODBC Driver implements specific functions:
Function
SQLConnect
SQLDriverConnect
SQLSpecialColumns
SQLProcedures
and
SQLProcedureColumns
All catalog functions
Description
SQLConnect
requires only a
DBQ
, user ID, and password.
SQLDriverConnect
uses the
DSN
,
DBQ
,
UID
, and
PWD keywords.
If
SQLSpecialColumns
is called with the
SQL_BEST_ROWID attribute, then it always returns the ROWID column.
Refer to the information in the following row.
If the
SQL_ATTR_METADATA_ID
statement attribute is set to
SQL_TRUE
, then a string argument is treated as an identifier argument, and its case is not significant. In this case, the underscore (_) and the percent sign (%) are treated as the actual character, and not as a search pattern character. In contrast, if this attribute is set to
SQL_FALSE
, then it is either an ordinary argument or a pattern value argument and is treated literally, and its case is significant.
SQLProcedures and SQLProcedureColumns
The
SQLProcedures
and
SQLProcedureColumns
calls have been modified to locate and return information about all procedures and functions even if they are contained within a package. In earlier releases, the calls only found procedures and functions that were outside of packages. The following examples and scenarios show what procedures or functions are returned if the
SQL_ATTR_METADATA_ID
attribute is set to
SQL_FALSE
.
Suppose that you have the following stored procedures:
"BAR"
"BARX"
"XBAR"
Using Oracle ODBC Driver E-13
Unicode Support
"XBARX"
"SQLPROCTEST.BAR"
"SQLPROCTEST.BARX"
"SQLPROCTEST.XBAR"
"SQLPROCTEST.XBARX"
When you look for
%
or
%%%%%%
, you get all eight procedures.
When you look for
%_
or
_%
, you get the following:
BAR
BARX
XBAR
XBARX
When you look for
.
or
.%
or
%.%
or
SQLPROC%.
or
SQLPROC%.%
, you get the following:
SQLPROCTEST.BAR
SQLPROCTEST.BARX
SQLPROCTEST.XBAR
SQLPROCTEST.XBARX
When you look for
%BAR
, you get the following:
BAR
XBAR
When you look for
.%BAR
or
%.%BAR
, you get the following:
SQLPROCTEST.BAR
SQLPROCTEST.XBAR
When you look for
SQLPROC%
or
.SQLPROC%
, you get the following: nothing (0 rows)
E.11.3 Implementation of the ODBC SQL Syntax
If a comparison predicate has a parameter marker as the second expression in the comparison and the value of that parameter is set to
SQL_NULL_DATA
with
SQLBindParameter
, then the comparison fails. This is consistent with the null predicate syntax in ODBC SQL.
E.11.4 Implementation of Data Types
For programmers, the most important part of the implementation of the data types concerns the
CHAR
,
VARCHAR
, and
VARCHAR2
data types.
For an fSqlType
value of
SQL_VARCHAR
,
SQLGetTypeInfo
returns the Oracle
Database data type
VARCHAR2
. For an fSqlType
value of
SQL_CHAR
,
SQLGetTypeInfo
returns the Oracle Database data type
CHAR
.
E.12 Unicode Support
This section provides information about Unicode support. It contains the following topics:
•
Unicode Support Within the ODBC Environment
(page E-15)
•
Unicode Support in ODBC API (page E-15)
E-14 Oracle Database Administrator's Reference
Unicode Support
•
(page E-16)
•
(page E-16)
E.12.1 Unicode Support Within the ODBC Environment
ODBC Driver Manager makes all ODBC drivers, regardless of whether they support
Unicode, appear as if they are Unicode compliant. This allows ODBC applications to be written independent of the Unicode capabilities of underlying ODBC drivers.
The extent to which the Driver Manager can emulate Unicode support for ANSI
ODBC drivers is limited by the conversions possible between the Unicode data and the local code page. Data loss is possible when the Driver Manager is converting from
Unicode to the local code page. Full Unicode support is not possible unless the underlying ODBC driver supports Unicode. Oracle ODBC Driver provides full
Unicode support.
E.12.2 Unicode Support in ODBC API
The ODBC API supports both Unicode and ANSI entry points using the
W
and
A
suffix convention. An ODBC application developer does not explicitly call entry points with the suffix. An ODBC application that is compiled with the
UNICODE
and
_UNICODE preprocessor definitions generates the appropriate calls. For example, a call to
SQLPrepare
compiles as
SQLPrepareW
.
The C data type,
SQL_C_WCHAR
, was added to the ODBC interface to allow applications to specify that an input parameter is encoded as Unicode or to request column data returned as Unicode. The macro
SQL_C_TCHAR
is useful for applications that must be built as both Unicode and ANSI. The
SQL_C_TCHAR
macro compiles as
SQL_C_WCHAR
for Unicode applications and as
SQL_C_CHAR
for ANSI applications.
The SQL data types,
SQL_WCHAR
,
SQL_WVARCHAR
, and
SQL_WLONGVARCHAR
, have been added to the ODBC interface to represent columns defined in a table as Unicode.
Potentially, these values are returned from calls to
SQLDescribeCol
,
SQLColAttribute
,
SQLColumns
, and
SQLProcedureColumns
.
Unicode encoding is supported for SQL column types NCHAR, NVARCHAR2, and
NCLOB. In addition, Unicode encoding is also supported for SQL column types
CHAR and VARCHAR2 if the character semantics are specified in the column definition.
Oracle ODBC Driver supports these SQL column types and maps them to ODBC SQL data types. The following table lists the supported SQL data types and the equivalent
ODBC SQL data type:
SQL Data Types
CHAR
VARCHAR2
NCHAR
NVARCHAR2
NCLOB
ODBC SQL Data Types
SQL_CHAR
or
SQL_WCHAR
SQL_VARCHAR
or
SQL_WVARCHAR
SQL_WCHAR
SQL_WVARCHAR
SQL_WLONGVARCHAR
Using Oracle ODBC Driver E-15
Unicode Support
E.12.3 SQLGetData Performance
The
SQLGetData
function allows an ODBC application to specify the data type to receive a column after the data has been fetched. OCI requires Oracle ODBC Driver to specify the data type before it is fetched. In this case, Oracle ODBC Driver uses information about the data type of the column (as defined in the database) to determine how to best default to fetching the column through OCI.
If a column that contains character data is not bound by
SQLBindCol
, then Oracle
ODBC Driver must determine if it should fetch the column as Unicode or as the local code page. The driver could always default to receiving the column as Unicode.
However, this may result in as many as two unnecessary conversions. For example, if the data were encoded in the database as ANSI, then there would be an ANSI to
Unicode conversion to fetch the data into Oracle ODBC Driver. If the ODBC application then requested the data as
SQL_C_CHAR
, then there would be an additional conversion to revert the data to its original encoding.
The default encoding of Oracle Database Client is used when fetching data. However, an ODBC application may overwrite this default and fetch the data as Unicode by binding the column or the parameter as the
WCHAR
data type.
E.12.4 Unicode Samples
Because Oracle ODBC Driver itself was implemented using
TCHAR
macros, it is recommended that ODBC application programs use
TCHAR
to take advantage of the driver.
The following examples show how to use
TCHAR
, which becomes the
WCHAR
data type if you compile with
UNICODE
and
_UNICODE
:
Example E-1 Connection to Database
To use this code, you only must specify the Unicode literals for
SQLConnect
.
HENV envHnd;
HDBC conHnd;
HSTMT stmtHnd;
RETCODE rc; rc = SQL_SUCCESS;
// ENV is allocated rc = SQLAllocEnv(&envHnd);
// Connection Handle is allocated rc = SQLAllocConnect(envHnd, &conHnd); rc = SQLConnect(conHnd, _T("stpc19"), SQL_NTS, _T("jones"), SQL_NTS, _T("password"),
SQL_NTS);
.
.
.
if (conHnd)
SQLFreeConnect(conHnd); if (envHnd)
SQLFreeEnv(envHnd);
Example E-2 Simple Retrieval
The following example retrieves the employee names and the job tiles from the
EMP table. With the exception that you must specify
TCHAR
compliant data to every ODBC function, there is no difference to the ANSI case. If the case is a Unicode application,
E-16 Oracle Database Administrator's Reference
Unicode Support then you must specify the length of the buffer to the
BYTE
length when you call
SQLBindCol
. For example, sizeof(ename)
.
/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
** SQLExecDirect
** SQLBindCol
** SQLFetch
**
*/ static SQLTCHAR *sqlStmt = _T("SELECT ename, job FROM emp");
SQLTCHAR ename[50];
SQLTCHAR job[50];
SQLINTEGER enamelen, joblen;
_tprintf(_T("Retrieve ENAME and JOB using SQLBindCol 1.../n[%s]/n"), sqlStmt);
// Step 1: Prepare and Execute rc = SQLExecDirect(stmtHnd, sqlStmt, SQL_NTS); // select checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 2: Bind Columns rc = SQLBindCol(stmtHnd,
1,
SQL_C_TCHAR,
ename,
sizeof(ename),
&enamelen); checkSQLErr(envHnd, conHnd, stmtHnd, rc); rc = SQLBindCol(stmtHnd,
2,
SQL_C_TCHAR,
job,
sizeof(job),
&joblen); checkSQLErr(envHnd, conHnd, stmtHnd, rc); do
{
// Step 3: Fetch Data
rc = SQLFetch(stmtHnd);
if (rc == SQL_NO_DATA)
break;
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
_tprintf(_T("ENAME = %s, JOB = %s/n"), ename, job);
} while (1);
_tprintf(_T("Finished Retrieval/n/n"));
Example E-3 Retrieval Using SQLGetData (Binding After Fetch)
This example shows how to use
SQLGetData
. There is no difference to the ANSI application in terms of Unicode-specific issues.
/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
** SQLExecDirect
** SQLFetch
Using Oracle ODBC Driver E-17
Unicode Support
** SQLGetData
*/ static SQLTCHAR *sqlStmt = _T("SELECT ename,job FROM emp"); // same as Case 1.
SQLTCHAR ename[50];
SQLTCHAR job[50];
_tprintf(_T("Retrieve ENAME and JOB using SQLGetData.../n[%s]/n"), sqlStmt); if (rc != SQL_SUCCESS)
{
_tprintf(_T("Failed to allocate STMT/n"));
goto exit2;
}
// Step 1: Prepare and Execute rc = SQLExecDirect(stmtHnd, sqlStmt, SQL_NTS); // select checkSQLErr(envHnd, conHnd, stmtHnd, rc); do
{
// Step 2: Fetch
rc = SQLFetch(stmtHnd);
if (rc == SQL_NO_DATA)
break;
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 3: GetData
rc = SQLGetData(stmtHnd,
1,
SQL_C_TCHAR,
(SQLPOINTER)ename,
sizeof(ename),
NULL);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
rc = SQLGetData(stmtHnd,
2,
SQL_C_TCHAR,
(SQLPOINTER)job,
sizeof(job),
NULL);
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
_tprintf(_T("ENAME = %s, JOB = %s/n"), ename, job);
} while (1);
_tprintf(_T("Finished Retrieval/n/n"));
Example E-4 Simple Update
This example shows how to update data. The length of data for
SQLBindParameter has to be specified with the BYTE length, even in Unicode application.
/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
** SQLPrepare
** SQLBindParameter
** SQLExecute
*/ static SQLTCHAR *sqlStmt = _T("INSERT INTO emp(empno,ename,job) VALUES(?,?,?)"); static SQLTCHAR *empno = _T("9876"); // Emp No static SQLTCHAR *ename = _T("ORACLE"); // Name static SQLTCHAR *job = _T("PRESIDENT"); // Job
E-18 Oracle Database Administrator's Reference
Unicode Support
_tprintf(_T("Insert User ORACLE using SQLBindParameter.../n[%s]/n"), sqlStmt);
// Step 1: Prepare rc = SQLPrepare(stmtHnd, sqlStmt, SQL_NTS); // select checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 2: Bind Parameter rc = SQLBindParameter(stmtHnd,
1,
SQL_PARAM_INPUT,
SQL_C_TCHAR,
SQL_DECIMAL,
4, // 4 digit
0,
(SQLPOINTER)empno,
0,
NULL); checkSQLErr(envHnd, conHnd, stmtHnd, rc); rc = SQLBindParameter(stmtHnd,
2,
SQL_PARAM_INPUT,
SQL_C_TCHAR,
SQL_CHAR,
lstrlen(ename)*sizeof(TCHAR),
0,
(SQLPOINTER)ename,
lstrlen(ename)*sizeof(TCHAR),
NULL); checkSQLErr(envHnd, conHnd, stmtHnd, rc); rc = SQLBindParameter(stmtHnd,
3,
SQL_PARAM_INPUT,
SQL_C_TCHAR,
SQL_CHAR,
lstrlen(job)*sizeof(TCHAR),
0,
(SQLPOINTER)job,
lstrlen(job)*sizeof(TCHAR),
NULL); checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 3: Execute rc = SQLExecute(stmtHnd); checkSQLErr(envHnd, conHnd, stmtHnd, rc);
Example E-5 Update and Retrieval for Long Data (CLOB)
This example may be the most complicated case to update and retrieve data for long data, like
CLOB
, in Oracle Database. Because the length of data should always be the
BYTE
length, the expression lstrlen(TCHAR data)*sizeof(TCHAR)
is needed to derive the
BYTE
length.
/*
** Execute SQL, bind columns, and Fetch.
** Procedure:
**
** SQLPrepare
** SQLBindParameter
Using Oracle ODBC Driver E-19
Unicode Support
** SQLExecute
** SQLParamData
** SQLPutData
**
** SQLExecDirect
** SQLFetch
** SQLGetData
*/ static SQLTCHAR *sqlStmt1 = _T("INSERT INTO clobtbl(clob1) VALUES(?)"); static SQLTCHAR *sqlStmt2 = _T("SELECT clob1 FROM clobtbl");
SQLTCHAR clobdata[1001];
SQLTCHAR resultdata[1001];
SQLINTEGER ind = SQL_DATA_AT_EXEC;
SQLTCHAR *bufp; int clobdatalen, chunksize, dtsize, retchklen;
_tprintf(_T("Insert CLOB1 using SQLPutData.../n[%s]/n"), sqlStmt1);
// Set CLOB Data
{
int i;
SQLTCHAR ch;
for (i=0, ch=_T('A'); i< sizeof(clobdata)/sizeof(SQLTCHAR); ++i, ++ch)
{
if (ch > _T('Z'))
ch = _T('A');
clobdata[i] = ch;
}
clobdata[sizeof(clobdata)/sizeof(SQLTCHAR)-1] = _T('/0');
} clobdatalen = lstrlen(clobdata); // length of characters chunksize = clobdatalen / 7; // 7 times to put
// Step 1: Prepare rc = SQLPrepare(stmtHnd, sqlStmt1, SQL_NTS); checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 2: Bind Parameter with SQL_DATA_AT_EXEC rc = SQLBindParameter(stmtHnd,
1,
SQL_PARAM_INPUT,
SQL_C_TCHAR,
SQL_LONGVARCHAR,
clobdatalen*sizeof(TCHAR),
0,
(SQLPOINTER)clobdata,
clobdatalen*sizeof(TCHAR),
&ind); checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 3: Execute rc = SQLExecute(stmtHnd); checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 4: ParamData (initiation) rc = SQLParamData(stmtHnd, (SQLPOINTER*)&bufp); // set value checkSQLErr(envHnd, conHnd, stmtHnd, rc); for (dtsize=0, bufp = clobdata;
dtsize < clobdatalen;
dtsize += chunksize, bufp += chunksize)
{
int len;
E-20 Oracle Database Administrator's Reference
Unicode Support
if (dtsize+chunksize<clobdatalen)
len = chunksize;
else
len = clobdatalen-dtsize;
// Step 5: PutData
rc = SQLPutData(stmtHnd, (SQLPOINTER)bufp, len*sizeof(TCHAR));
checkSQLErr(envHnd, conHnd, stmtHnd, rc);
}
// Step 6: ParamData (temination) rc = SQLParamData(stmtHnd, (SQLPOINTER*)&bufp); checkSQLErr(envHnd, conHnd, stmtHnd, rc); rc = SQLFreeStmt(stmtHnd, SQL_CLOSE);
_tprintf(_T("Finished Update/n/n")); rc = SQLAllocStmt(conHnd, &stmtHnd); if (rc != SQL_SUCCESS)
{
_tprintf(_T("Failed to allocate STMT/n"));
goto exit2;
}
// Clear Result Data memset(resultdata, 0, sizeof(resultdata)); chunksize = clobdatalen / 15; // 15 times to put
// Step 1: Prepare rc = SQLExecDirect(stmtHnd, sqlStmt2, SQL_NTS); // select checkSQLErr(envHnd, conHnd, stmtHnd, rc);
// Step 2: Fetch rc = SQLFetch(stmtHnd); checkSQLErr(envHnd, conHnd, stmtHnd, rc); for(dtsize=0, bufp = resultdata;
dtsize < sizeof(resultdata)/sizeof(TCHAR) && rc != SQL_NO_DATA;
dtsize += chunksize-1, bufp += chunksize-1)
{
int len; // len should contain the space for NULL termination
if (dtsize+chunksize<sizeof(resultdata)/sizeof(TCHAR))
len = chunksize;
else
len = sizeof(resultdata)/sizeof(TCHAR)-dtsize;
// Step 3: GetData
rc = SQLGetData(stmtHnd,
1,
SQL_C_TCHAR,
(SQLPOINTER)bufp,
len*sizeof(TCHAR),
&retchklen);
} if (!_tcscmp(resultdata, clobdata))
{
_tprintf(_T("Succeeded!!/n/n"));
} else
{
_tprintf(_T("Failed!!/n/n"));
}
Using Oracle ODBC Driver E-21
Performance and Tuning
E.13 Performance and Tuning
This section contains the following topics:
•
General ODBC Programming Guidelines (page E-22)
•
Data Source Configuration Options (page E-22)
•
(page E-24)
E.13.1 General ODBC Programming Guidelines
Apply the following programming guidelines to improve the performance of an
ODBC application:
• Enable connection pooling if the application frequently connects and disconnects from a data source. Reusing pooled connections is extremely efficient compared to reestablishing a connection.
• Minimize the number of times a statement must be prepared. Where possible, use bind parameters to make a statement reusable for different parameter values.
Preparing a statement once and running it several times is much more efficient than preparing the statement for every
SQLExecute
.
• Do not include columns in a
SELECT
statement of which you know the application does not retrieve; especially
LONG
columns. Because of the nature of the database server protocols, Oracle ODBC Driver must fetch the entire contents of a
LONG
column if it is included in the
SELECT
statement, regardless of whether the application binds the column or performs a
SQLGetData
operation.
• If you are performing transactions that do not update the data source, then set the
SQL_ATTR_ACCESS_MODE
attribute of the ODBC
SQLSetConnectAttr
function to
SQL_MODE_READ_ONLY
.
• If you are not using ODBC escape clauses, then set the
SQL_ATTR_NOSCAN attribute of the ODBC
SQLSetConnectAttr
function or the ODBC
SQLSetStmtAttr
function to true.
• Use the ODBC
SQLFetchScroll
function instead of the ODBC
SQLFetch function for retrieving data from tables that have a large number of rows.
E.13.2 Data Source Configuration Options
This section discusses the performance implications of the following ODBC data source configuration options:
• Enable Result Sets
This option enables the support of returning result sets (for example,
RefCursor
) from procedure calls. The default is enabling the returning of result sets.
Oracle ODBC Driver must query the database server to determine the set of parameters for a procedure and their data types in order to determine if there are any
RefCursor
parameters. This query incurs an additional network round trip the first time any procedure is prepared and executed.
• Enable LOBs
E-22 Oracle Database Administrator's Reference
Performance and Tuning
This option enables the support of inserting and updating LOBs. The default is enabled.
Oracle ODBC Driver must query the database server to determine the data types of each parameter in an
INSERT
or
UPDATE
statement to determine if there are any LOB parameters. This query incurs an additional network round trip the first time any
INSERT
or
UPDATE
is prepared and run.
See Also:
Oracle Database SecureFiles and Large Objects Developer's Guide
for more information about LOBs
Note:
LOB data compression enables you to compress SecureFiles to gain disk,
Input-Output, and redo logging savings. This reduces costs as compression utilizes space most efficiently and improves the performance of SecureFiles as compression reduces Input-Output and redo logging.
LOB data encryption provides enhanced database security. While the encrypted data is available for random reads and writes, the data is more secure.
Data compression and encryption consumes some additional memory.
• Bind
TIMESTAMP
as
DATE
Binds
SQL_TIMESTAMP
parameters as the appropriate Oracle Database data type.
If this option is set to
TRUE
, then
SQL_TIMESTAMP
binds as the Oracle
DATE
data type. If this option is set to
FALSE
, then
SQL_TIMESTAMP
binds as the Oracle
TIMESTAMP
data type, which is the default.
• Enable Closing Cursors
The
SQL_CLOSE
option of the ODBC function,
SQLFreeStmt
, is supposed to close associated cursors with a statement and discard all pending results. The application can reopen the cursor by running the statement again without doing a
SQLPrepare again. A typical scenario for this would be an application that expects to be idle for a while but reuses the same SQL statement again. While the application is idle, it may want to free up any associated server resources.
The OCI, on which Oracle ODBC Driver is layered, does not support the functionality of closing cursors. Therefore, by default, the
SQL_CLOSE
option has no effect in Oracle ODBC Driver. The cursor and associated resources remain open on the database.
Enabling this option causes the associated cursor to be closed on the database server. However, this results in the parse context of the SQL statement being lost.
The ODBC application can run the statement again without calling
SQLPrepare
.
However, internally, Oracle ODBC Driver must prepare and run the statement all over. Enabling this option has a severe performance impact on applications that prepare a statement once and run it repeatedly.
This option should only be enabled if freeing the resources on the server is necessary.
• Fetch Buffer Size
Using Oracle ODBC Driver E-23
Performance and Tuning
Set the Fetch Buffer Size (
FetchBufferSize
) in the odbc.ini
file to a value specified in bytes. This value is the amount of memory needed that determines how many rows of data Oracle ODBC Driver pre-fetches at a time from an Oracle
Database to the client's cache regardless of the number of rows the application program requests in a single query, thus improving performance.
There is an improvement in the response time of applications that typically fetch fewer than 20 rows of data at a time, particularly over slow network connections or from heavily loaded servers. Setting this too high can have an adverse effect on response time or consume large amounts of memory. The default is 64,000 bytes.
You should choose an optimal value for the application.
When the
LONG
and
LOB
data types are present, the number of rows pre-fetched by Oracle ODBC Driver is not determined by the Fetch Buffer Size. The inclusion of the
LONG
and
LOB
data types minimizes the performance improvement and could result in excessive memory use. Oracle ODBC Driver ignores the Fetch
Buffer Size and only pre-fetches a set number of rows in the presence of the
LONG and
LOB
data types.
See Also:
"
Format of the Connection String for the SQLDriverConnect Function
(page E-3)"
E.13.3 DATE and TIMESTAMP Data Types
If a
DATE
column in the database is used in a
WHERE
clause and the column has an index, then there can be an impact on the performance. For example:
SELECT * FROM EMP WHERE HIREDATE = ?
In this example, an index on the
HIREDATE
column could be used to make the query run quickly. However, because
HIREDATE
is a
DATE
value and Oracle ODBC Driver is supplying the parameter value as
TIMESTAMP
, the query optimizer of Oracle Database must apply a conversion function. To prevent incorrect results (as might happen if the parameter value had nonzero fractional seconds), the optimizer applies the conversion to the
HIREDATE
column resulting in the following statement:
SELECT * FROM EMP WHERE TO_TIMESTAMP(HIREDATE) = ?
However, this has the effect of disabling the use of the index on the
HIREDATE column. Instead, the server performs a sequential scan of the table. If the table has many rows, then this can take a long time. As a workaround for this situation, Oracle
ODBC Driver has the connection option to bind
TIMESTAMP
as
DATE
. When this option is enabled, Oracle ODBC Driver binds
SQL_TIMESTAMP
parameters as the
Oracle
DATE
data type instead of the Oracle
TIMESTAMP
data type. This enables the query optimizer to use any index on the
DATE
columns.
Note:
This option is intended only for use with Microsoft Access or other similar programs that bind
DATE
columns as
TIMESTAMP
columns. It should not be used when there are actual
TIMESTAMP
columns present or when data loss may occur. Microsoft Access runs such queries using whatever columns are selected as the primary key.
E-24 Oracle Database Administrator's Reference
Error Messages
E.14 Error Messages
When an error occurs, Oracle ODBC Driver returns the native error number, the
SQLSTATE
(an ODBC error code), and an error message. The driver derives this information both from errors detected by the driver and errors returned by Oracle
Database.
Native Error
For errors that occur in the data source, Oracle ODBC Driver returns the native error returned to it by Oracle Database. When Oracle ODBC Driver or the Driver Manager detects an error, Oracle ODBC Driver returns a native error of zero.
SQLSTATE
For errors that occur in the data source, Oracle ODBC Driver maps the returned native error to the appropriate
SQLSTATE
. When Oracle ODBC Driver or the Driver Manager detects an error, it generates the appropriate
SQLSTATE
.
Error Message
For errors that occur in the data source, Oracle ODBC Driver returns an error message based on the message returned by Oracle Database. For errors that occur in Oracle
ODBC Driver or the Driver Manager, Oracle ODBC Driver returns an error message based on the text associated with the
SQLSTATE
.
Error messages have the following format:
[vendor] [ODBC-component] [data-source] error-message
The prefixes in brackets ([ ]) identify the source of the error. The following table shows the values of these prefixes returned by Oracle ODBC Driver. When the error occurs in the data source, the vendor
and
ODBC-component
prefixes identify the vendor and name of the ODBC component that received the error from the data source.
Error Source
Driver Manager
Oracle ODBC Driver
Oracle Database
Prefix
[vendor]
[ODBC-component]
[data-source]
[vendor]
[ODBC-component]
[data-source]
[vendor]
[ODBC-component]
[data-source]
Value
[unixODBC]
[Driver Manager]
Not applicable
[ORACLE]
[Oracle ODBC Driver]
Not applicable
[ORACLE]
[Oracle ODBC Driver]
[Oracle OCI]
For example, if the error message does not contain the
Ora
prefix shown in the following format, then error is an Oracle ODBC Driver error and should be selfexplanatory.
[Oracle][ODBC]Error message text here
Using Oracle ODBC Driver E-25
Error Messages
If the error message contains the
Ora
prefix shown in the following format, then it is not an Oracle ODBC Driver error.
[Oracle][ODBC][Ora]Error message text here
Note:
Although the error message contains the
ORA-
prefix, the actual error may originate from one of several sources.
If the error message text starts with the
ORA-
prefix, then you can obtain more information about the error in Oracle Database documentation.
E-26 Oracle Database Administrator's Reference
F
Database Limits
This appendix describes database limits.
F.1 Database Limits
The following table lists the default and maximum values for parameters in a
CREATE
DATABASE
or
CREATE CONTROLFILE
statement.
Note:
Interdependencies between these parameters may affect permissible values.
Table F-1 CREATE CONTROLFILE and CREATE DATABASE Parameters
Parameter
MAXLOGFILES
MAXLOGMEMBERS
MAXLOGHISTORY
MAXDATAFILES
MAXINSTANCES
Default
16
2
100
30
1
Maximum Value
4220
5
65534
65534
1055
The following table lists the Oracle Database file size limits in bytes.
Table F-2 File Size Limits
File Type Platform
Data files Any
File size limit
4,194,303 multiplied by the value of the
DB_BLOCK_SIZE
parameter
2,147,483,647 bytes Import/
Export files and
SQL*Load er files
Import/
Export files and
SQL*Load er files
Oracle Solaris, Linux, IBM AIX on
POWER Systems (64-Bit), and HP-
UX: 32-bit files
Oracle Solaris, Linux, IBM AIX on
POWER Systems (64-Bit), and HP-
UX: 64-bit files
Unlimited
Note
: File size is limited by limits allowed by the operating system on different file systems.
Database Limits F-1
Database Limits
Table F-2 (Cont.) File Size Limits
File Type Platform
Control files
Oracle Solaris, Linux, IBM AIX on
POWER Systems (64-Bit), and HP-
UX
File size limit
25000 control file blocks with a block size of 4096 bytes.
F-2 Oracle Database Administrator's Reference
Symbols
@ abbreviation,
A
A_TERMCAP environment variable,
ADA_PATH environment variable,
administering command line SQL,
AIX tools
Base Operation System tools,
Performance Tool Box Manager,
System Management Interface tools,
AIXTHREAD_SCOPE environment variable,
archive buffers
ASM_DISKSTRING initialization parameter,
assistants
Oracle Database Configuration Assistant,
Oracle Database Upgrade Assistant,
Oracle Net Configuration Assistant,
asynchronous flag in SGA, asynchronous input/output
Automatic Storage Management
stopping,
Automatic Storage Management, using,
automating shutdown,
startup,
B
bit-length support,
block size
buffer cache tuning size,
Index
buffer manager,
C
C library for,
catching routine example,
CLASSPATH environment variable,
client shared libraries, client static libraries,
COBDIR environment variable,
commands iostat, lsps,
sar,
SPOOL,
swapinfo,
vmstat,
common environment
configuration files ottcfg.cfg,
pccfor.cfg,
CPU_COUNT initialization parameter,
D
database block size,
database block size
Index-1
database limits,
DB_BLOCK_SIZE initialization parameter,
DB_CACHE_SIZE initialization parameter,
DB_FILE_MULTIBLOCK_READ_COUNT parameter,
demo_proc32.mk file,
demonstration programs for Pro*COBOL,
Oracle JDBC/OCI,
Pro*C/C++,
demonstrations
precompiler,
direct input/output, disk input/output
file system type, input/output
slaves,
pacing,
disks
monitoring performance,
DISPLAY environment variable,
dynamic linking
Oracle libraries and precompilers,
E
environment variables
A_TERMCAP,
AIXTHREAD_SCOPE,
DISPLAY,
for Pro*COBOL,
HOME,
LANGUAGE,
LD_LIBRARY_PATH,
LD_OPTIONS,
LIBPATH,
MicroFocus COBOL compiler,
ORACLE_BASE,
ORACLE_HOME,
Index-2
environment variables (continued)
,
ORACLE_TRACE,
ORAENV_ASK,
,
PRINTER,
TNS_ADMIN,
TWO_TASK,
executables
precompilers,
F
file systems
OCFS2,
S5,
files
glogin.sql,
ins_precomp.mk,
Oracle Net Services configuration,
ottcfg.cfg,
pccfor.cfg,
privgroup, root.sh,
FORMAT precompiler
Pro*COBOL,
G
getprivgrp command,
,
GPFS
H
HP-UX dynamic processor reconfiguration,
hugetlbfs
I
I/O buffers and SQL*Loader,
I/O support
implementing asynchronous input/output,
initialization parameters
CPU_COUNT,
DB_CACHE_SIZE,
LOG_BUFFERS,
input/output
slaves,
installing
iostat command,
ireclen,
J
JAVA_POOL_SIZE initialization parameters,
JFS2 considerations,
JFSconsiderations,
Journaled file system,
,
L
LANGUAGE environment variable,
LARGE_POOL_SIZE initialization parameters,
LD_LIBRARY_PATH environment variable,
LD_OPTIONS environment variable,
libraries client shared and static,
lightweight timer implementation,
Linux resource management,
listener listener (continued) setting up for TCP/IP or TCP/IP with Secure
LOG_BUFFERS initialization parameters, login.sql file,
LPDEST environment variable,
M
make files custom,
ins_precomp.mk,
MAXDATAFILES parameter,
MAXLOGMEMBERS parameter,
memory contention,
tuning,
MLOCK privilege,
Multi-CPU Binding (MCB),
multiple signal handlers,
O
OCCI
OCI
operating system buffer cache, tuning, operating system commands
running,
setprivgrp,
operating system tools for AIX, iostat,
lsps, sar,
swapinfo,
vmstat,
ORA_NLS10 environment variable,
ORA_TZFILE environment variable,
Oracle block size, adjusting,
Index-3
Oracle buffer manager,
Oracle Call Interface demonstration programs,
Oracle Cluster Services Synchronization Daemon starting,
stopping,
Oracle Database
Oracle Database Client:,
Oracle Database Configuration Assistant configuring,
Oracle Database environment variables
Oracle Database process stopping,
Oracle Database tuning and large memory allocations,
Oracle Database Upgrade Assistant,
Oracle environment variables
ORA_NLS10,
ORACLE_BASE,
ORACLE_HOME,
ORACLE_SID,
Oracle JDBC/OCI demonstration programs,
Oracle Net Configuration Assistant using,
Oracle Net Services configuration files,
Secure Sockets Layer protocol,
TCP/IP protocol,
Oracle ODBC Driver,
Oracle Protocol Support
TCP/IP protocol,
TCP/IP with Secure Sockets Layer protocol,
Oracle Solaris resource management,
Oracle Solaris tools,
ORACLE_BASE environment variable,
ORACLE_HOME environment variable,
ORACLE_PATH environment variable,
ORACLE_SID environment variable,
ORACLE_TRACE environment variable,
ORAENV_ASK environment variable,
P
page-out activity, paging
allocating sufficient,
Index-4
paging (continued) controlling, tuning, parameters
DB_FILE_MULTIBLOCK_READ_COUNT,
MAXDATAFILES,
MAXLOGMEMBERS,
SGA_MAX_SIZE,
,
pcscfg.cfg file,
Performance Tool Box Agent,
postinstallation tasks
precompiler executables
precompilers
executables,
Pro*C/C++,
Pro*COBOL,
signals,
uppercase to lowercase conversion,
value of ireclen and oreclen, vendor debugger programs,
PRINTER environment variable,
privgroup file,
Pro*C/C++
make files, signals,
Pro*COBOL
environment variables,
naming differences,
Pro*FORTRAN demonstration programs,
R
raw devices buffer cache size,
removing
resilvering, with Oracle Database,
restarting
Automatic Storage Management,
Oracle Database, restrictions, SQL*Plus
passwords,
S
sar command,
SCHED_NOAGE enabling,
scheduling policy,
scripts setprivgrp command,
SGA
SHARED_POOL_SIZE initialization parameters,
SHLIB_PATH environment variable,
shm_max parameter,
shm_seg parameter,
shmmax parameter,
shmseg parameter,
shutdown automating,
SIGINT signal,
SIGIO signal,
signal handlers,
signal routine
signals
SIGCLD,
SIGINT,
SIGIO,
SIGPIPE,
signals (continued)
SIGURG,
SIGURG signal,
SPOOL command
SQL*Loader,
SQL*Module for Ada
SQL*Plus command line Help,
default editor, editor,
PRODUCT_USER_PROFILE table, restrictions, site profile,
running operating system commands,
user profile,
using command-line SQL*Plus,
SQL*Plus command line Help installing,
starting
Oracle Cluster Services Synchronization Daemon,
startup
static linking
Oracle libraries and precompilers,
stopping
Oracle Cluster Services Synchronization Daemon,
swap space
tuning,
swapon command,
SYSDATE,
system editor
system time,
T
tables
Index-5
TCP/IP with Secure Sockets Layer protocol,
Transparent Hugepages
disable for Oracle Database servers,
troubleshooting
ocssd.log threads blocked,
tuning disk input/output,
input/output bottlenecks,
memory management,
tuning tools
iostat command,
lsps command,
Performance Tool Box Manager,
sar command,
swapinfo command,
TWO_TASK environment variable,
U
UNIX System V file system,
upgraded databases upgraded databases (continued) upgrading,
user interrupt handler,
user profile
user programs for Pro*C/C++,
OCI,
Pro*C/C++,
Pro*COBOL,
SQL*Module for Ada,
using command-line SQL*Plus, utilities
adapters,
Import,
symfind,
V
Veritas file system,
virtual memory data pages
virtual memory page size, default,
X
X/Open Distributed Transaction Processing XA interface,
XA functionality,
Index-6
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