If Oracle is configured with a Physical Standby, and the Oracle LOG_ARCHIVE_DEST_n initialization parameter is configured with the DELAY option, running a Full Load and Apply Changes task on an Oracle Physical Standby instance may result in missing or erroneous data in the target database.
The following warning may be thrown in the log files:
Using standby database could have caused the missing events problem during Full Load and CDC synchronization.
If you do not have the DELAY parameter configured and there is no data loss, this warning message can be ignored. Please check with your DBA if the DELAY parameter is set.
Resolution:
This issue can be resolved using an internal parameter: standbyDelayTime, which should be set to a value little bit bigger than the Delay parameter of LOG_ARCHIVE_DEST_n initialization parameter. Units are in minutes.
For information on how to set internal parameters, see Qlik Replicate: How to set Internal Parameters and what are they for?
This solution may lead to redundant records for a table without PK/UI if there were INSERT operations during that period. Example - LOG_ARCHIVE_DEST_2 = 'DELAY=10'
Environment
Qlik Replicate
Related Content:
Supported standby configurations | Qlik Replicate Help
