From: Michael Stone <mstone+postgres@mathom.us>
To: Martijn van Oosterhout <kleptog@svana.org>
Cc: pgsql-hackers@postgresql.org
Cc: pgsql-performance@postgresql.org
Subject: Re: [HACKERS] A Better External Sort?
Date: Wed, 05 Oct 2005 05:41:25 -0400
Message-ID: <20051005094125.GW2241@mathom.us> (raw)
In-Reply-To: <20051001161936.GE13830@svana.org>
References: <25552174.1128176560482.JavaMail.root@elwamui-polski.atl.sa.earthlink.net>
<20051001161936.GE13830@svana.org>
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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To: pgsql-performance@postgresql.org
Cc: mstone+postgres@mathom.us, kleptog@svana.org, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] A Better External Sort?
In-Reply-To: <20051005094125.GW2241@mathom.us>
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