Message-ID: <4382EB58.3020804@openwide.fr>
Date: Tue, 22 Nov 2005 10:56:40 +0100
From: Guillaume Smet <guillaume.smet@openwide.fr>
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To: Qingqing Zhou <zhouqq@cs.toronto.edu>
CC: pgsql-performance@postgresql.org
Subject: Re: weird performances problem
References: <437CC21D.8070402@openwide.fr> <dlugsf$25o5$1@news.hub.org>
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Qingqing Zhou wrote:
> Someone is doing a massive *write* at this time, which makes your query 
> *read* quite slow. Can you find out which process is doing write?

Indexes should be in memory so I don't expect a massive write to slow 
down the select queries. sdb is the RAID10 array dedicated to our data 
so the postgresql process is the only one to write on it. I'll check 
which write queries are running because there should really be a few 
updates/inserts on our db during the day.

On a four days log analysis, I have the following:
SELECT  403,964
INSERT 	574
UPDATE 	393
DELETE 	26
So it's not really normal to have a massive write during the day.

Thanks for your help

--
Guillaume