To: Jeff Frost <jeff@frostconsultingllc.com>
cc: pgsql-performance@postgresql.org
Subject: Re: Index usage problem on 8.3.3 
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Comments: In-reply-to Jeff Frost <jeff@frostconsultingllc.com>
	message dated "Thu, 30 Oct 2008 18:49:21 -0700"
Date: Thu, 30 Oct 2008 21:55:58 -0400
Message-ID: <15839.1225418158@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Jeff Frost <jeff@frostconsultingllc.com> writes:
> On Thu, 30 Oct 2008, Tom Lane wrote:
>>> Any idea why I don't see it on 8.3.4?
>> 
>> I think it's more likely some small difference in your test conditions
>> than any real version-to-version difference.  In particular I think the
>> "still see" test might be influenced by the ages of transactions running
>> concurrently.

> Interesting.  This is on a test server which has no other concurrent 
> transactions and it acts the same way after I stopped 8.3.4 and started up 
> 8.3.3 again as it did before stopping 8.3.3 to bring up 8.3.4.  Hrmm..I'm not 
> sure that makes sense.  So, I did the test with the sql script on 8.3.3, then 
> shut down 8.3.3, started up 8.3.4 on the same data dir, ran the test 
> successfully.  Next I shut down 8.3.4 and started 8.3.3 and verified that the 
> behavior was still the same on 8.3.3.  I wonder what else I might be doing 
> differently.

Huh.  That does sound like it's a version-to-version difference.
There's nothing in the CVS log that seems related though.  Are you
willing to post your test case?

			regards, tom lane