Message-ID: <45E918AF.7040309@zigo.dhs.org>
Date: Sat, 03 Mar 2007 07:41:51 +0100
From: Dennis Bjorklund <db@zigo.dhs.org>
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To: Carlos Moreno <moreno_pg@mochima.com>
Cc: PostgreSQL Performance <pgsql-performance@postgresql.org>
Subject: Re: Upgraded to 8.2.3 --- still having performance issues
References: <45E5B7D2.5020306@mochima.com>
In-Reply-To: <45E5B7D2.5020306@mochima.com>
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Carlos Moreno skrev:
> The system does very frequent insertions and updates --- the longest
> table has, perhaps, some 20 million rows, and it's indexed (the primary
> key is the combination of two integer fields).  This longest table only
> has inserts (and much less frequent selects), at a peak rate of maybe
> one or a few insertions per second.

One or a few inserts per second doesn't sound like that much. I would 
have expected it to work. If you can you might want to group several 
inserts into a single transaction.

A standard hint is also to move the WAL onto its own disk. Or get a disk 
controller with battery backed up ram.

But it's hard to say from your description what the bottleneck is and 
thus hard to give any advice.

> Any help/tips/guidance in troubleshooting this issue?  It will be
> much appreciated!

You could try to find specific queries that are slow. Pg can for example 
log queries for you that run for longer than X seconds.

/Dennis