Re: Index usage problem on 8.3.3 - Mailing list pgsql-performance

From Jeff Frost
Subject Re: Index usage problem on 8.3.3
Date
Msg-id Pine.LNX.4.64.0810301843201.17153@discord.home.frostconsultingllc.com
Whole thread Raw
In response to Re: Index usage problem on 8.3.3  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Index usage problem on 8.3.3
List pgsql-performance
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.

The good news is that making the indexes before the updates seems to make the
planner happy!

--
Jeff Frost, Owner     <jeff@frostconsultingllc.com>
Frost Consulting, LLC     http://www.frostconsultingllc.com/
Phone: 916-647-6411    FAX: 916-405-4032

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