Re: autovacuum stress-testing our system

Excerpts from Simon Riggs's message of jue sep 27 06:51:28 -0300 2012:
> On 26 September 2012 15:47, Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
> >
> > Really, as far as autovacuum is concerned, it would be much more useful
> > to be able to reliably detect that a table has been recently vacuumed,
> > without having to request a 10ms-recent pgstat snapshot.  That would
> > greatly reduce the amount of time autovac spends on pgstat requests.
>
> VACUUMing generates a relcache invalidation. Can we arrange for those
> invalidations to be received by autovac launcher, so it gets immediate
> feedback of recent activity without polling?

Hmm, this is an interesting idea worth exploring, I think.  Maybe we
should sort tables in the autovac worker to-do list by age of last
invalidation messages received, or something like that.  Totally unclear
on the details, but as I said, worth exploring.

--
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services