Ensuring Data Availability for Classic Capture
To ensure the continuity and integrity of capture processing when Extract operates in classic capture mode, enable archive logging.
The archive logs provide a secondary data source should the online logs recycle before Extract is finished with them. The archive logs for open transactions must be retained on the system in case Extract needs to recapture data from them to perform a recovery.
WARNING:
If you cannot enable archive logging, there is a high risk that you will need to completely resynchronize the source and target objects and reinstantiate replication should there be a failure that causes an Extract outage while transactions are still active. If you must operate this way, configure the online logs according to the following guidelines to retain enough data for Extract to capture what it needs before the online logs recycle. Allow for Extract backlogs caused by network outages and other external factors, as well as long-running transactions.
In a RAC configuration, Extract must have access to the online and archived logs for all nodes in the cluster, including the one where Oracle GoldenGate is installed.