Hello,
We have configured oracle dataguard with physical standby. Everything seemd okay most of times. But when high redo generates on primary db, there are huge standby apply lag gap. Almost 12 hours.
We did increased redo log group numbers and also its size from 8GB to 16GB for decrease frequently log switch. Also sometimes checkpoint not completed occured. Therefore we increased group and size of Redolog. Also we increased recovery_parallelism from 0 to 200. There are no CPU utilization on standby server. Almost 5%.
There are no log transport lag during that time.
Also there are high configuration sessions on standby server during apply lag time. These configuration sessions are
- Checkpoint completed
- flashback buf free by rvwr