Re: Autovacuum on by default?

Matthew T. O'Connor wrote:
> Peter Eisentraut wrote:
> > Is it time to turn on autovacuum by default in 8.2? I know we wanted to
> > be on the side of caution with 8.1, but perhaps we should evaluate the
> > experiences now. Comments?
>
> Would be fine by me, but I'm curious to see what the community has to
> say. A few comments:
>
> Autovacuum can cause unpredictable performance issues, that is if it
> vacuums in the middle of a busy day and people don't want that, of
> course they turn it off easy enough, but they might be surprised.
>
> I haven't played with CVS HEAD much, but I think the logging issue has
> been addressed no? That is my single biggest gripe with the 8.1
> autovacuum is that it's very hard to see if it's actually done anything
> without having to turn up the logging significantly.

This has not been addressed, except that pg_stat_activity now shows
autovacuum. Someone was going to work on per-module log output, but it
wasn't completed for 8.2. Does pg_stat_activity now show the table
being vacuumed?

> The remaining big ticket items for autovacuum are the maintenance window
> that Alvaro and I have just been discussing, and multiple concurrent
> vacuum, (possibly you could add the continued reduction of vacuum impact
> but that just a constant thing). Do we think it's worth waiting for
> either of these two features prior to turning on autovacuum by default?

Probably not. It can always be turned off by people who don't want it
on.

--
Bruce Momjian bruce(at)momjian(dot)us
EnterpriseDB http://www.enterprisedb.com

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