> Well, i have a very large database, with vary tables and very
> registers. Every day, too many operations are perfomed in that DB, with
> queries that insert, delete and update. Once a week some statistics are
> collected using vacuum analyze.
Have vacuum analyze running once an HOUR if it's very busy. If you are
using 7.4, run the pg_autovacuum daemon that's in contrib/pg_autovacuum.
> The problem is after a period of time (one month, i think), the
> queries takes too much time to perform. A simple update can take 10
> seconds or more to perform.
If running vacuum analyze once an hour doesn't help, try running a
vacuum full once a week or something to fix the problem.
Also, try upgrading to 7.4 which has indexes that won't suffer from bloat.
Chris