Re: random slow query

From: Alan Hodgson <ahodgson(at)simkin(dot)ca>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: random slow query
Date: 2009-06-30 18:47:20
Message-ID: 200906301147.20384@hal.medialogik.com
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On Tuesday 30 June 2009, Mike Ivanov <mikei(at)activestate(dot)com> wrote:
> Hi Scott,
>
> > Well, we can't be sure OP's only got one core.
>
> In fact, we can, Sean posted what top -b -n 1 says. There was only one
> CPU line.
>

Recent versions of top on Linux (on RedHat 5 anyway) may show only one
combined CPU line unless you break them out with an option.

> > the number of cores, it's the IO subsystem is too slow for the load.
> > More cores wouldn't fix that.
>
> While I agree on the IO, more cores would definitely help to improve
> ~6.5 load average.

No, I agree with the previous poster. His load is entirely due to IO wait.
Only one of those processes was trying to do anything. IO wait shows up as
high load averages.

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