Received: from localhost (maia-1.hub.org [200.46.204.191])
	by postgresql.org (Postfix) with ESMTP id 65A3C9FBAD7
	for <pgsql-performance-postgresql.org@postgresql.org>;
	Tue, 20 Feb 2007 19:35:32 -0400 (AST)
Received: from postgresql.org ([200.46.204.71])
	by localhost (mx1.hub.org [200.46.204.191]) (amavisd-new, port 10024)
	with ESMTP id 42484-06 for
	<pgsql-performance-postgresql.org@postgresql.org>;
	Tue, 20 Feb 2007 19:35:26 -0400 (AST)
X-Greylist: delayed 00:13:27.316836 by SQLgrey-1.7.4
Received: from k2.nmr.varianinc.com (host-70-69.varianinc.com [4.22.70.69])
	by postgresql.org (Postfix) with ESMTP id 86BD89FBAB8
	for <pgsql-performance@postgresql.org>;
	Tue, 20 Feb 2007 19:35:26 -0400 (AST)
Received: from [10.190.213.112] (khaos [10.190.213.112])
	by k2.nmr.varianinc.com (8.9.3+Sun/8.9.1) with ESMTP id QAA18478
	for <pgsql-performance@postgresql.org>;
	Tue, 20 Feb 2007 16:21:56 -0700 (MST)
Message-ID: <45DB8290.1020501@varianinc.com>
Date: Tue, 20 Feb 2007 16:21:52 -0700
From: Glenn Sullivan <glenn.sullivan@varianinc.com>
Organization: Chemagnetics/Varian NMR
User-Agent: Mozilla Thunderbird 1.0.7-1.4.1 (X11/20050929)
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: pgsql-performance@postgresql.org
Subject: SELECT performance problem
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Spam-Status: No, hits=0.001 tagged_above=0 required=5 tests=BAYES_50
X-Spam-Level: 
X-Archive-Number: 200702/202
X-Sequence-Number: 23256

I am updating from 7.4.5 to 8.2.3.  I have noticed a significant
slowdown in simple searches such as
     "select filename from vnmr_data where seqfil = 'sems';"
This returns 12 rows out of 1 million items in the table.
On 7.4.5, this takes about 1.5 seconds.  On 8.2.3, it is taking
about 9 seconds.

I have played with different values of:
work_mem, temp_buffers, shared_buffers and effective_cache_size
and none of them make any difference.

I am running on redhat Linux 4   64bit.

Any ideas?

Glenn