From: db@zigo.dhs.org
To: Jérôme BENOIS <benois@argia-engineering.fr>
Cc: PostgreSQL Performance <pgsql-performance@postgresql.org>
Cc: Xavier Milliard <milliard@argia.fr>
Cc: Laurent BELMONTE <belmonte@argia.fr>
Subject: Re: BitMapScan performance degradation
Date: Tue, 21 Nov 2006 16:12:47 +0100 (CET)
Message-ID: <3389.192.121.104.120.1164121967.squirrel@zigo.dhs.org> (raw)
In-Reply-To: <1164100889.5281.184.camel@localhost.localdomain>
References: <1164100889.5281.184.camel@localhost.localdomain>
> When enable_bitmapscan is enabled this query cost 51893.491 ms and when
> is disabled 117.709 ms. But i heard bitmapscan feature improved
> performance, can you help me ?
The standard question we always ask first is if you have run VACUUM
ANALYZE recently?
Are all the costs and estimated number of rows the same after you have run
VACUUM ANALYZE? If not you might want to show that new plan as well.
/Dennis
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: db@zigo.dhs.org, benois@argia-engineering.fr, milliard@argia.fr, belmonte@argia.fr
Subject: Re: BitMapScan performance degradation
In-Reply-To: <3389.192.121.104.120.1164121967.squirrel@zigo.dhs.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox