Re: log_autovacuum

Simon Riggs wrote:
> On Tue, 2007-04-17 at 14:06 -0400, Alvaro Herrera wrote:

> > I've tinkered with this patch a bit.  Sample output:
> >
> > LOG:  automatic vacuum of table "alvherre.public.foo": index scans: 0
> >         pages: removed 0, 11226 remain
> >         tuples: 1300683 removed, 1096236 remain
> >         system usage: CPU 0.29s/0.38u sec elapsed 2.56 sec
> >
> > Please comment.
>
> Well, 'tis great except when you have very very frequent autovacuums.
> That was why I wanted it in 1 log line.
>
> Perhaps we need this as an integer, so we can log all vacuums that last
> for longer in seconds than the setting, 0 logs all. That would
> significantly reduce the volume if we set it to 5, say. That way you
> would get your readability and I would get my reasonable size logs.

It kinda smells funny to have a setting like that.  Do we have a
precedent?  If other people is OK with it, I'll do that.

Would it work to add a separate GUC var to control the minimum autovac
time?  Also, why do it by time and not by amount of tuples/pages
removed?

> Presumably you mean to have both removeds in the same order?
> >         pages: 0 removed, 11226 remain
> >         tuples: 1300683 removed, 1096236 remain

Right, fixed.

Also, here is the patch.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support