The DDC DB can contain any variable, except those listed above that must be known in order to connect to the DDC database.
When DDC DB is used, the SET command automatically updates the DDC DB. If this is not desired,
MEMORY_SET command can be used to set the setting in memory only. This is useful for temporary variable setting in scripts, when the variable change is not meant to be persistent.
Note that MINE_UNIQUE_ID variable is set by the -setup.dbvrep script and if DDC DB is not used, DDC file must be manually updated with the new value. The purpose of this variable is to distinguish between repeated runs of setup scripts.
The dbvrep parameter --no-ddcdb (or --noddcdb) disables the LOAD DDCDB command. This is used for the first time startup, when the DDC DB is yet to be created and thus LOAD DDCDB would fail.
DDC Commands
A DDC file can be created from the DDCDB. The command is:
CREATE DDCFILE filename FROM DDCDB
The DDC file will be created in the filename specified.
A DDC DB can be created from a DDC file. The command is:
CREATE DDCDB FROM DDCFILE
This takes the active DDC file that dbvrep has been loaded with (through readddc or --ddfile commands) and loads the settings into the DDC DB.
DDC_BACKUP_DIR
On every startup of a process a backup of all DDC settings is made into the DDC_BACKUP_DIR directory as a backup, e.g. for use with CREATE DDCDB FROM DDCFILE, or just for reference.
Network encryption
All network commands among fetcher, mine, apply and console are sent encrypted. The key serves both as authentication and encryption.
On WAN networks, even the redo/plog contents is sent encrypted.
The key is defined by variable NETWORK_TRAFFIC_KEY. As this can be considered as sensitive information, there are more ways how to specify this value:
• DDC file (use memory_set, so it is not stored in DDC DB automatically)
•
DDC DB
• the .ssh way: create a private directory (chmod 0700), store a file with a single command
“memory_set NETWORK_TRAFFIC_KEY …” and include it from your DDC file (standard READ command)
• specify the key as dbvrep parameter: --netkey
Dbvisit Replicate Dictionary tables
Usually, there is no need to directly access most of the tables. Nevertheless, some of the tables can be interesting:
DBRSAPPLY_CONFLICT_LOG
List of conflicts encountered, including failing SQL.
DBRSAPPLY_CONFLICT_HANDLERS
Conflict handler settings. Note that the key is object id on source database.
Dbvisit Replicate Installation Guide and User Manual © Dbvisit Software Limited.
Except as specifically set out the Dbvisit license agreement, nothing in this Documentation constitutes a warranty as to the operation of the Dbvisit software.
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DBRSAPPLY
Includes last commit SCN (current_scn), so it can be used to monitor apply progress if SNMP or log monitoring is not an option.
Dbvisit Replicate Installation Guide and User Manual © Dbvisit Software Limited.
Except as specifically set out the Dbvisit license agreement, nothing in this Documentation constitutes a warranty as to the operation of the Dbvisit software.
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