Scheduled jobs

I didn't find any documentation mentioning scheduled jobs. I assume there is no such a feature
yet. I would like to implement it if someone helps me with the development process (I am brand new
to OpenSource projects).

Basically the feature should include scheduling function exeution at:   - postmaster startup   - postmaster shutdown
-a specified moment   - a time of the day/month/year   - recurring at a time interval
 

I know this could be implemented in exernal processes but from an application standpoint it would
be much more consistent if all the database-related functionality is in the database server.
Besides, both Oracle and Microsoft have the feature.

Please advise.

Thanks,
Zlatko


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