Learned an interesting one today. I noticed that the nightly stats job was not running on any of our data guard logical standbys. It would not run despite running a complete remove/reset the scheduled maintenance window, resetting the parameters for the job, etc. A fellow DBA tipped me off to this issue which applies to 10.2.0.4 logical standbys (enterprise ed, any platform). Apparently dbms_scheduler just doesn’t run on logicals in 10.2.0.4 without a fix.
To resolve it you can set an event as follows:
stop log apply
alter system set event = ‘10793 trace name context forever, level 2’ scope=spfile;
restart the database and restart log apply
I have yet to be able to implement this so YMMV. We will probably put it in place over the next few weeks.