Re: [HACKERS] A Better External Sort?

From: Michael Stone <mstone+postgres(at)mathom(dot)us>
To: Martijn van Oosterhout <kleptog(at)svana(dot)org>
Cc: pgsql-hackers(at)postgresql(dot)org, pgsql-performance(at)postgresql(dot)org
Subject: Re: [HACKERS] A Better External Sort?
Date: 2005-10-05 09:41:25
Message-ID: 20051005094125.GW2241@mathom.us
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On Sat, Oct 01, 2005 at 06:19:41PM +0200, Martijn van Oosterhout wrote:
>COPY TO /dev/null WITH binary
>13MB/s 55% user 45% system (ergo, CPU bound)
[snip]
>the most expensive. But it does point out that the whole process is
>probably CPU bound more than anything else.

Note that 45% of that cpu usage is system--which is where IO overhead
would end up being counted. Until you profile where you system time is
going it's premature to say it isn't an IO problem.

Mike Stone

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