Message-ID: <45817B2F.7070502@freesurf.fr>
Date: Thu, 14 Dec 2006 17:26:23 +0100
From: Arnaud Lesauvage <thewild@freesurf.fr>
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: Ragnar <gnari@hive.is>, Jens Schipkowski <jens.schipkowski@apus.co.at>,
	pgsql-performance@postgresql.org
Subject: Re: Slow update with simple query
References: <457FDB1E.6040801@freesurf.fr>
 <op.tkhy4jpg81rjf6@xjens.apus.local>
	<457FF0CD.4050606@freesurf.fr> <op.tkh10qgw81rjf6@xjens.apus.local>
	<4580025D.2040903@freesurf.fr>
	<1166021340.6369.103.camel@localhost.localdomain>
	<45801A1B.6070200@freesurf.fr> <8399.1166028385@sss.pgh.pa.us>
	<4581593E.8080401@freesurf.fr> <20426.1166109494@sss.pgh.pa.us>
	<45816C54.5010602@freesurf.fr> <21233.1166113140@sss.pgh.pa.us>
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Tom Lane a écrit :
> I think the conclusion must be that there was just too much I/O to be
> done to update all the rows.  Have you done any tuning of shared_buffers
> and so forth?  I recall having seen cases where update performance went
> bad as soon as the upper levels of a large index no longer fit into
> shared_buffers ...

Yes, that's probably it.
I think my raid1 array's performances are very bad.
I am switching to a brand new hardware next week, I am quite confident that this 
will solve many problems.

Thanks for helping !

Regards
--
Arnaud