Scott Whitney escribió:
> I'd like to phone in with a slightly different opinion on VACUUM FULL. Yeah,
> it should be avoided when possible, but it's not always possible. In our
> case, I've got 300ish databases backing to a single database server. Each of
> those dbs has a couple of hundred tables and a hundred or more views. The
> product (Journyx Timesheet) is pretty complex, and I find that if I do _not_
> perform a full vacuum once per week, my customer dbs start to slow down
> inordinately. Queries which would run in 1-2 seconds will run in 30-40
> seconds after a few weeks of not performing a full vacuum. I've got autovac
> running on all dbs.
That's most likely because you have too small an FSM. Have you tuned
that?
> Now, that could well be due to index bloat with complex indexes,
VACUUM FULL does not clean indexes.
> or it could be due to a variety of other factors, but also my pg_clog
> directory does not clear out, but continues to create new clog
> segments.
That's expected. If pg_clog size bothers you, there's another parameter
you can tweak. However, pg_clog size should not normally be a problem;
it's just 32kB for every million transactions or something like that.
--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support