Date: Tue, 1 Nov 2005 03:00:26 +0100
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
To: PostgreSQL <martin@portant.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: 8.1beta3 performance
Message-ID: <20051101020026.GA4707@uio.no>
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On Mon, Oct 31, 2005 at 05:16:46PM -0600, PostgreSQL wrote:
> We're running 8.1beta3 on one server and are having ridiculous performance 
> issues.  This is a 2 cpu Opteron box and both processors are staying at 98 
> or 99% utilization processing not-that-complex queries.  Prior to the 
> upgrade, our I/O wait time was about 60% and cpu utilization rarely got very 
> high, now I/O wait time is at or near zero.

It sounds like some query got planned a different way that happened to be
really suboptimal -- I've seen really bad queries be quick on earlier
versions "by accident" and then not have the same luck on later versions.

Could you find out what queries are taking so long (use
log_min_duration_statement), and post table definitions and EXPLAIN ANALYZE
output here?

/* Steinar */
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Homepage: http://www.sesse.net/