Questions About Incremental checkpoint on the Primary and Redo Transport to Standby
This is a four-instance primary, 10.2.0.4 maximum performance with a single instance standby using RTA. Both are on AIX 5.3 TL 12. The primary is very large (about 20 TB) and the DBA recently grew the online redo logs from 1 GB to 5 GB. The larger size is useful during the busy times; it generates about 4 logs/hour with 5 GB logs instead of around 100/hour when they were 1 GB.
When activity slows we can see just one archived log every four hours. There are multiple incremental checkpoints between log switches. The problem is that the service destination for the standby is not selected until the primary completes all the incremental checkpoints and switches to the next log. This means that the standby can lag the primary by many hours.