To: Antoine <melser.anton@gmail.com>
cc: pgsql-performance@postgresql.org
Subject: Re: new to postgres (and db management) and performance already a
	problem :-(
In-reply-to: <43CC1938.7020807@gmail.com> 
References: <43CC1938.7020807@gmail.com>
Comments: In-reply-to Antoine <melser.anton@gmail.com>
	message dated "Mon, 16 Jan 2006 23:07:52 +0100"
Date: Mon, 16 Jan 2006 17:43:30 -0500
Message-ID: <18875.1137451410@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Antoine <melser.anton@gmail.com> writes:
> So... seeing as I didn't really do any investigation as to setting 
> default sizes for storage and the like - I am wondering whether our 
> performance problems (a programme running 1.5x slower than two weeks 
> ago) might not be coming from the db (or rather, my maintaining of it). 

That does sound like a lack-of-vacuuming problem.  If the performance
goes back where it was after VACUUM FULL, then you can be pretty sure
of it.  Note that autovacuum is not designed to fix this for you: it
only ever issues regular vacuum not vacuum full.

> I couldn't find an easy way to check for disk accessings.

Watch the output of "vmstat 1" or "iostat 1" for info about that.

			regards, tom lane