Re: Patch: Tie stats options to autovacuum in postgresql.conf

["Florian G. Pflug" <fgp(at)phlo(dot)org>]

Jim C. Nasby wrote:
> On Thu, Sep 28, 2006 at 03:07:39PM -0700, David Wheeler wrote:
> > PostgreSQLers,
> >
> > I just ran into an issue where a client thought that autovacuum was  
> > running but it wasn't. This is because it's not fatal when autovacuum  
> > is on but stats_start_collector and/or stats_row_level is off. I  
> > suspect that there's a reason that it's not fatal, so I thought that  
> > it might be useful to give folks just a little bit of help by telling  
> > them in postgresql.conf that they need to enable them in order for  
> > autovacuum to work.
>
> +1. I was just at a client today that had run into this problem.
>
> Actually, I'm in favor of refusing to start if autovac is on but the
> proper stats settings aren't. I'd rather that then people ending up with
> bloated databases and crappy performance.
If think that setting autovacuum to on should even force
stats_collector and stats_row_level to on - together with a warning if
they would otherwise be off.

The risk of autovacuum being disabled by accident seems to risk a much
worse performance penatly then having the statistics collector running
by accident. Additionally, the statistics collector can easily be turned
off within seconds even _if_ it was on accidentally, but if vacuuming was
disabled by accident, the user might have to run "vacuum full" - with all
the concurrency issues that this implies..

greetings, Florian flug