So is there anything I can do in 8.3 to help this? I have tried setting ' track_activities', 'track_counts' and 'autovacuum' to 'off' (which has reduced CPU and I/O a bit) - but the stats collector process is still using up a good deal of CPU and I/O - is there any way to turn stats collecting completely off? Scott Otis CIO / Lead Developer Intand www.intand.com -----Original Message----- From: Magnus Hagander [mailto:magnus@xxxxxxxxxxxx] Sent: Friday, September 04, 2009 1:19 AM To: Scott Otis Cc: Robert Haas; Ivan Voras; pgsql-performance@xxxxxxxxxxxxxx Subject: Re: Seeking performance advice and explanation for high I/O on 8.3 On Fri, Sep 4, 2009 at 08:54, Scott Otis<scott.otis@xxxxxxxxxx> wrote: > Robert Haas <robertmhaas@xxxxxxxxx>: > >> Do you by any chance have a bazillion databases in this cluster? Can >> you do these? > >> select sum(1) from pg_database; > > 1555 Note that there are two features in 8.4 specifically designed to deal with the situation where you have lots of databases and/or lots of tables (depending on how many tables you have in each database, this would definitely qualify). They both deal with the "pgstats temp file too large generating i/o issue". First, it will only write the file when it's actually necessary - 8.3 and earlier will always write it. Second, you will have the ability to move the location of the file to a different filesystem - specifically intended so that you can move it off to a ramdrive. Could be worth investigating an upgrade for this issue alone. The fact that you don't have to struggle with tuning the FSM in 8.4 is another thing that makes life a *lot* easier in this kind of installations. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
