Received: from localhost (uranus.hub.org [200.46.204.60]) by postgresql.org (Postfix) with ESMTP id 853C59FA594 for ; Tue, 21 Nov 2006 13:01:31 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.60]) (amavisd-new, port 10024) with ESMTP id 72926-04-5 for ; Tue, 21 Nov 2006 13:01:28 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from svr4.postgresql.org (svr4.postgresql.org [66.98.251.159]) by postgresql.org (Postfix) with ESMTP id 9DC859FA999 for ; Tue, 21 Nov 2006 13:00:58 -0400 (AST) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.3 Received: from smtp17.orange.fr (smtp17.orange.fr [193.252.23.111]) by svr4.postgresql.org (Postfix) with ESMTP id 462465AF922 for ; Tue, 21 Nov 2006 16:07:28 +0000 (GMT) Received: from smtp-msa-out17.orange.fr (mwinf1702 [172.22.148.24]) by mwinf1710.orange.fr (SMTP Server) with ESMTP id 570E81C0900F for ; Tue, 21 Nov 2006 16:36:15 +0100 (CET) Received: from [192.168.1.162] (LSt-Amand-152-32-6-178.w82-127.abo.wanadoo.fr [82.127.21.178]) by mwinf1702.orange.fr (SMTP Server) with ESMTP id 890877000063; Tue, 21 Nov 2006 16:36:02 +0100 (CET) X-ME-UUID: 20061121153602561.890877000063@mwinf1702.orange.fr Subject: Re: BitMapScan performance degradation From: =?ISO-8859-1?Q?J=E9r=F4me?= BENOIS To: db@zigo.dhs.org Cc: PostgreSQL Performance , Xavier Milliard , Laurent BELMONTE In-Reply-To: <3389.192.121.104.120.1164121967.squirrel@zigo.dhs.org> References: <1164100889.5281.184.camel@localhost.localdomain> <3389.192.121.104.120.1164121967.squirrel@zigo.dhs.org> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-/baoliXvj3LIeO/Oldla" Date: Tue, 21 Nov 2006 16:35:56 +0100 Message-Id: <1164123356.5281.256.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.8.1 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200611/175 X-Sequence-Number: 21945 --=-/baoliXvj3LIeO/Oldla Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi Dennis, Le mardi 21 novembre 2006 =C3=A0 16:12 +0100, db@zigo.dhs.org a =C3=A9crit = : > > 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 ? >=20 > The standard question we always ask first is if you have run VACUUM > ANALYZE recently? Yes i ran VACCUUM ANALYZE just before my EXPLAIN. > Are all the costs and estimated number of rows the same after you have ru= n > VACUUM ANALYZE? If not you might want to show that new plan as well. >=20 > /Dennis J=C3=A9r=C3=B4me. --=-/baoliXvj3LIeO/Oldla Content-Type: application/pgp-signature; name=signature.asc Content-Description: Ceci est une partie de message =?ISO-8859-1?Q?num=E9riquement?= =?ISO-8859-1?Q?_sign=E9e?= -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (GNU/Linux) iD8DBQBFYxzcCDKlmlhpwnERAvD8AJ9oyQ0eh67HJcN2R6OmIn7b4WL66QCfSlig XyeGYUWnuic4J4bL445Dpac= =1iNK -----END PGP SIGNATURE----- --=-/baoliXvj3LIeO/Oldla--