Message-ID: <44B94A51.9050108@joeconway.com>
Date: Sat, 15 Jul 2006 13:04:33 -0700
From: Joe Conway <mail@joeconway.com>
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To: Gabriele Turchi <gabriele.turchi@l39a.com>
CC: Michael Fuhr <mike@fuhr.org>,  pgsql-performance@postgresql.org,
	Marco Colombo <marco@esiway.net>
Subject: Re: Big differences in plans between 8.0 and 8.1
References: <1152972852.3541.0.camel@apollo5.casa.intranet>	
	<20060715190210.GA76277@winnie.fuhr.org>
	<1152993350.3541.22.camel@apollo5.casa.intranet>
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Gabriele Turchi wrote:
> Running an ANALYZE really change the plan, now it is fast as before
> (8.0).
> 
> On the production system a VACUUM FULL ANALYZE is run every morning
> after a clean-up, when the "registrazioni" table is empty. During the
> day this table fills up (about 500 record any day), and apparently the
> performances are free-falling very quickly. This behaviour has not
> changed between the old and the new installation.	
> 
> Can you suggest an easy way to collect and keep up-to-date these
> statistics in a very low-impact way?
> 

Why not just periodically (once an hour?) run "ANALYZE registrazioni;" 
during the day. This will only update the statistics, and should be very 
low impact.

HTH,

Joe