On Thu, Aug 17, 2006 at 12:41:57PM -0400, 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.
Anyone in that situation needs to be more hands-on with the database
anyway. I think the big target for autovac is beginners who otherwise
would bloat themselves silly (of course, it's also very useful far
beyond beginners, but by that time an admin should have some clue about
what they're doing).
And +1 on Rod's suggestion to make it more aggressive. I always drop the
scale factor to at least 0.2 and 0.1 (though 0.1 and 0.05 don't seem
unreasonable), and typically drop the thresholds to 200 and 100 (though
again, lower is probably warrented).
Actually, on a table small enough for the thresholds to kick in it's
going to be extremely fast to vacuum anyway, and the table is probably
either static or changing very rapidly. I'm wondering if maybe they
should just default to 0?
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461