Re: elegant and effective way for running jobs inside a database

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: Simon Riggs <simon@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, Artur Litwinowicz <admin@ybka.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2012-03-07T21:10:56Z
Lists: pgsql-hackers
Merlin Moncure <mmoncure@gmail.com> writes:
> sure, I get that, especially in regards to procedures.  a server
> ticker though is a pretty small thing and it's fair to ask if maybe
> that should be exposed instead of (or perhaps in addition to) a job
> scheduling system.

I don't want to have a server-side ticker at all, especially not one
that exists only for a client that might or might not be there.  We've
been doing what we can to reduce PG's idle-power consumption, which is
an important consideration for large-data-center applications.  Adding a
new source of periodic wakeups is exactly the wrong direction to be
going.

There is no need for a ticker to drive a job system.  It should be able
to respond to interrupts (if a NOTIFY comes in) and otherwise sleep
until the precalculated time that it next needs to launch a job.

			regards, tom lane