Determining How Much Data to Retain

When managing log retention, try to ensure rapid access to the logs that Extract would require to perform a normal recovery (not a Bounded Recovery). See Log Retention Requirements per Extract Recovery Mode. If you must move the archives off the database system, the TRANLOGOPTIONS parameter provides a way to specify an alternate location. See Specifying the Archive Location.

The recommended retention period is at least 24 hours worth of transaction data, including both online and archived logs. To determine the oldest log that Extract might need at any given point, issue the SEND EXTRACT command with the SHOWTRANS option. You might need to do some testing to determine the best retention time given your data volume and business requirements.

If data that Extract needs during processing was not retained, either in online or archived logs, one of the following corrective actions might be required:

• Alter Extract to capture from a later point in time for which log data is available (and accept possible data loss on the target).

• Resynchronize the source and target data, and then start the Oracle GoldenGate environment over again.