From: Steinar H. Gunderson <sgunderson@bigfoot.com>
To: pgsql-performance@postgresql.org
Subject: Re: Massive performance issues
Date: Thu, 1 Sep 2005 23:52:45 +0200
Message-ID: <20050901215245.GA4242@uio.no> (raw)
In-Reply-To: <20050901211359.GD7131@pongo.lshift.net>
References: <20050901174231.GE23970@pongo.lshift.net>
<43176A95.70506@tweakers.net>
<20050901211359.GD7131@pongo.lshift.net>
On Thu, Sep 01, 2005 at 10:13:59PM +0100, Matthew Sackman wrote:
> Well that's the thing - on the queries where it decides to use the index
> it only reads at around 3MB/s and the CPU is maxed out, whereas when it
> doesn't use the index, the disk is being read at 60MB/s. So when it
> decides to use an index, I don't seem to be IO bound at all. Or at least
> that's the way it seems to me.
You are I/O bound; your disk is doing lots and lots of seeks. The SATA
interface is not the bottleneck; the disk's ability to rotate and move its
heads is.
/* Steinar */
--
Homepage: http://www.sesse.net/
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To: pgsql-performance@postgresql.org
Cc: sgunderson@bigfoot.com
Subject: Re: Massive performance issues
In-Reply-To: <20050901215245.GA4242@uio.no>
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