Since Oracle Database 10g we have automatic maintenance jobs in the database running. Since Oracle Database 11g (and the same applies to 12c) we have:
- Weekday Jobs being able to get executed from 10pm until 2am on MON-FRI
- Weekend Jobs being able to get executed from 6am until 2am on SAT-SUN
A support colleague contacted me a while ago asking why at his customer the jobs don’t start anymore as they have set the duration for weekdays to 15 minutes. You may adjust the window generally by yourself with:
- exec DBMS_SCHEDULER.SET_ATTRIBUTE(‘MONDAY_WINDOW’,’DURATION’,numtodsinterval(2,’hour’));
But in this particular case only changing the default setting of _autotask_min_window=14 helped. That ensured that – once the job window was set to as little as 15 minutes that Automatic Maintenance Jobs still get executed. Once you adjust your Maintenance Windows making them really small ensure that you’ll adjust this little underscore as well.