From: Christopher Browne <cbbrowne@acm.org>
Subject: Re: scalablility problem
Date: Fri, 30 Mar 2007 21:18:18 -0400
Organization: cbbrowne Computing Inc
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Message-ID: <874po2tdlx.fsf@wolfe.cbbrowne.com>
References: <460D7220.9010302@cse.ohio-state.edu>
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To: pgsql-performance@postgresql.org

Quoth dingxn@cse.ohio-state.edu (Xiaoning Ding):
> When I run multiple TPC-H queries (DBT3) on  postgresql, I found the system
> is not scalable.  My machine has 8GB memory, and 4 Xeon Dual Core processor
> ( 8 cores in total). OS kernel is linux 2.6.9. Postgresql is 7.3.18. I

> I think it might be caused by some contentions. But I do not know postgresql
> much. May anybody give me some clue to find the reasons?

Two primary issues:

1.  You're running a horrendously ancient version of PostgreSQL.  The
7.3 series is Really Old.  Newer versions have *enormous*
improvements that are likely to be *enormously* relevant.

Upgrade to 8.2.

2.  There are known issues with the combination of Xeon processors and
PAE memory addressing; that sort of hardware tends to be *way* less
speedy than the specs would suggest.

There have been "context switching" issues on this sort of hardware
that are enormously worsened if you're running on a version of
PostgreSQL that is 4 major releases out of date.
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