Here is a real world example where a scheduler in PostgreSQL would be
helpful. We collect usage statistics from our network throughout the
day (raw stats.) After midnight, we roll up those raw stats into daily
statistics.
We have a very large amount of data, about 2 million rows a day a
growing, so I want this whole operation done on the database server.
It's all database work, just summing up data from one table and putting
the result in another table. We have all that logic in a stored
procedure. So why do I need to set up a cron job and a shell script
whose only task is to connect to the database and start up the stored
procedure? Wouldn't it be much simpler just to have a schedule in
PostgreSQL that says "at 12:01, run this stored procedure"?
Another advantage to having a scheduler in the database is to ease your
DBA's job in maintenance, and to coordinate work by multiple systems.
--
Guy Rouillier