Thank you all for the fast responses! I changed the delete's schedule from daily to hourly and I will let you know the result. This seems to be the most promising step. The next one is tuning 'max_fsm_pages'. Increasing max_fsm_pages can be also helpful, but I've read that 'vacuum verbose ...' will issue warnings if max_fsm_pages is too small. I've never seen such messag, this command is either run and finish or goes to an endless loop as it was written in my initial e-mail. On Thu, Oct 29, 2009 at 10:59:48AM -0600, Scott Marlowe wrote: > On Thu, Oct 29, 2009 at 8:44 AM, Peter Meszaros <pme@xxxxxxxxx> wrote: > > Hi All, > > > > I use postgresql 8.3.7 as a huge queue. There is a very simple table > > with six columns and two indices, and about 6 million records are > > written into it in every day continously commited every 10 seconds from > > 8 clients. The table stores approximately 120 million records, because a > > cron job daily deletes those ones are older than 20 day. Autovacuum is > > on and every settings is the factory default except some unrelated ones > > (listen address, authorization). But my database is growing, > > characteristically ~600MByte/day, but sometimes much slower (eg. 10MB, > > or even 0!!!). > > Sounds like you're blowing out your free space map. Things to try: > > 1: delete your rows in smaller batches. Like every hour delete > everything over 20 days so you don't delete them all at once one time > a day. > 2: crank up max fsm pages large enough to hold all the dead tuples. > 3: lower the autovacuum cost delay > 4: get faster hard drives so that vacuum can keep up without causing > your system to slow to a crawl while vacuum is running. -- E-mail: pmeATprolanDOThu Phone: +36-20-954-3100/8139 Mobile: +36-20-9543139 Fax: +36-26-540420 http://www.prolan.hu Mon Nov 2 13:20:39 CET 2009 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
