Setting Job Priority outside of Scheduler Windows

Question

We have a scheduled email job, EMAIL_RELAY, that should run every 15 minutes. We also have 8000
separate batch jobs that run in a Window, SAVED_SEARCHES_WINDOW, between
02:00 and 07:00. During the Window, the email job fails to run. When I look at the first email job that runs after the window closes I see that the job was requested to start at 02:00 but the actual start time was 07:00. The database is very busy during the saved searches window, but I would like the scheduler to run the email job every 15 minutes regardless. I have read in the docs that the you can prioritize jobs, but to me it looks like this is only within a window. I cannot see how I can add the EMAIL_RELAY job to the SAVED_SEARCHES_WINDOW as still get it to repeat every 15 minutes so changing the priority seems useless.
Any ideas?
Thanks

Answer 1

Hi,
- it is possible to prioritize jobs that are waiting to be run by setting the JOB_PRIORITY attribute of the job . You may run into an issue with so many (>1000) jobs in the waiting queue. If so you may need to put the higher priority e--mail jobs in a different class which points to a different service
- it may be that you have set the job slave limit too low. Please check the value of job_queue_processes
select value from v$parameter where name='job_queue_processes';
and of max_job_slave_processes (from the all_scheduler_global_attribute view) to make sure both are high enough.
- if both limits are high enough (or as high as you want to set them) but you want to make sure that your e-mail job always runs you can use the techniques on this thread
Run Jobs One After Another
to setup two classes, one for high-priority jobs and one for all other jobs and reserve a given number of slave processes for each class. You can have a resource plan in effect outside a window (as well as in a window) and the resource plan is what allocates resources between job classes (via resource consumer groups).
Hope this helps,
Ravi.