Message-ID: <4EE0F3F4.8040909@digsys.bg>
Date: Thu, 08 Dec 2011 19:29:24 +0200
From: Kaloyan Iliev Iliev <kaloyan@digsys.bg>
Reply-To: kaloyan@digsys.bg
Organization: Register.BG Ltd.
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To: pgsql-performance@postgresql.org
Subject: Slow query after upgrade from 8.2 to 8.4
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Hello All.
We recently upgrade our server from PG8.2 to 8.4.
Our current version is:
database=> SELECT version();
                                                      
version                                                      
--------------------------------------------------------------------------------------------------------------------
 PostgreSQL 8.4.8 on amd64-portbld-freebsd8.2, compiled by GCC cc (GCC) 
4.2.2 20070831 prerelease [FreeBSD], 64-bit
(1 row)
 
I read and setup most of the tuning advices.
Since the upgrade we have some very complicated reports that start 
working too slow. Form tens of seconds to 1 hours.
I execute vacuum analyze before start the query.

Here I will post explain analyze. If you think it is necessary I will 
post the exact query:
http://explain.depesz.com/s/J0O

I think the planner didn't choose the best plan. I will try to I rewrite 
the query and set join_collapse_limit to 1 and see what will happen. 
Meanwhile any suggestions are welcome.

Best regards and thanks in advance for the help.
 Kaloyan Iliev