If you run Oracle RAC on 10.2.0.2 or 9i watch out for the following.
I’ve seen on a certain occasions when there is heavy system activity, all instances in RAC hang, even connecting as sysdba was terribly slow. It turned out this was due to the sequence SYS.AUDSES$ has its cache setting at default value of 20. Metalink note: 395314.1 mentions that the some of the symptoms are:
- Checkpoint not completing on all RAC nodes
- Waits expire on row cache enqueue lock dc_sequences
- RAC hangs due to QMON deadlocking
It also mentions the fix to increase the cache size to a large value.
alter sequence sys.audses$ cache 10000;
Apparently this is fixed in 10.2.0.3.
