Sizing and Retaining the Logs

When tables are defined with DATA CAPTURE CHANGES, more data is logged than when they are defined with DATA CAPTURE NONE . If any of the following is true, you might need to increase the number and size of the active and archived logs.

Your applications generate large amounts of DB2 data.
Your applications have infrequent commits.
You expect to stop Extract for long periods of time.
Your network is unreliable or slow.

To control log retention, use the DSN6LOGP MAXARCH system parameter in the DSNTIJUZ installation job.

Retain enough log data so that Extract can start again from its checkpoints after you stop it or after an unplanned outage. Extract must have access to the log that contains the start of the oldest uncommitted unit of work, and all logs thereafter.

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 tables, and then start the Oracle GoldenGate environment over again.

Note:

The IBM documentation makes recommendations for improving the performance of log reads. In particular, you can use large log output buffers, large active logs, and make archives to disk.