On Wed, 28 Oct 2009, Denis BUCHER wrote:
For now, we only planned a VACUUM ANALYSE eacha night.
You really want to be on a later release than 8.1 for an app that is heavily deleting things every day. The answer to most VACUUM problems is "VACUUM more often, preferrably with autovacuum", and using 8.1 puts you into a position where that's not really practical. Also, 8.3 and 8.4 are much faster anyway.
8.4 in particular has a fix for a problem you're very likely to run into with this sort of workload (running out of max_fsm_pages when running VACUUM), so if you're going to upgrade I would highly recommend targeting 8.4 instead of an earlier version.
But the database complained about checkpoint_segments (currently = 3) What should be changed first to improve speed ?
http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server covers this parameter and some of the others you should be considering. If your goal is just to nail the major bottlenecks and get the configuration in the right neighborhood, you probably only need to consider the setting down to the work_mem section; the ones after that are more advanced than you probably need.
-- * Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
