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8.2 Query 10 times slower than 8.1 (view-heavy)

From: "Evan Carroll" <lists(at)evancarroll(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Subject: 8.2 Query 10 times slower than 8.1 (view-heavy)
Date: 2007-08-28 15:22:11
Message-ID: 428b865e0708280822u522391ecr5366bb5a6647f1aa@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-performance
Dearest dragon hunters and mortal wanna-bes,

I recently upgraded a system from Apache2/mod_perl2 to
Lighttpd/fastcgi. The upgrade went about as rough as can be. While in
the midst of a bad day, I decided to make it worse, and upgrade Pg 8.1
to 8.2. Most people I talk to seem to think 8.1 was a lemon release;
not I. It worked excellent for me for the longest time, and I had no
good reason to upgrade it, other than to just have done so. In the
process, A query that took a matter of 2minutes, started taking hours.
I broke that query up into something more atomic and used it as a
sample.

The following material is provided for your assisting-me-pleasure: the
original SQL; the \ds for all pertinent views and tables; the output
of Explain Analyze; and the original query.

The original query both trials was: SELECT * FROM test_view where U_ID = 8;

test_view.sql =   http://rafb.net/p/HhT9g489.html

8.1_explain_analyze =  http://rafb.net/p/uIyY1s44.html
8.2_explain_analzye =  http://rafb.net/p/mxHWi340.html

\d table/views = http://rafb.net/p/EPnyB229.html

Yes, I ran vacuum full after loading both dbs.

Thanks again, ask and I will provide anything else. I'm on freenode,
in #postgresql, and can be found at all times with the nick
EvanCarroll.

-- 
Evan Carroll
System Lord of the Internets
me(at)evancarroll(dot)com
832-445-8877

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Next:From: Scott MarloweDate: 2007-08-28 15:32:01
Subject: Re: 8.2 Query 10 times slower than 8.1 (view-heavy)
Previous:From: Pallav KalvaDate: 2007-08-28 15:09:00
Subject: 8.2.4 Chooses Bad Query Plan

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