Re: pg_autovacuum integration attempt #2

Peter Eisentraut wrote:
> Matthew T. O'Connor wrote:
> > I think it's ready to apply barring any feedback to the contrary.
> > Actually I do have a small improvement I will send in tomorrow (sorry
> > can't do it any sooner) that defaulted autovac_enabled to false, and
> > makes autovac fail more gracefully when the stats system is not
> > enabled, but that shouldn't stop you from applying this patch.
>
> A nitpick on that parameter name:  There is not reason to abbreviate
> "autovacuum": there is enough space.  And the "_enabled" is redundant.

Agreed.  Nitpicks are important too because it makes us so beautiful.  :-)

> > The thing I was trying to do was use the GUC hook function to make
> > sure that the required GUC variables are also set before GUC reports
> > autovac as enabled.  This seemed cleaner to me, but apparently it
> > won't work since it seems that autovac_enabled is read from GUC
> > before the stats variables, and there is no way to force the order in
> > which they are read.  Am I missing something?
>
> What I am missing at least is what you really mean by "the required GUC
> variables are also set".  GUC variables are always set to something (at
> least after the initialization phase, but you don't get to do anything
> with GUC before the initialization, obviously).

He means he has to have the stats collector enabled along with
autovacuum, and he doesn't have a way to effectively test that stats are
enabled when enabling autovacuum because the ordering of postgresql.conf
variable loads isn't predefined.

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