Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 6B5729FB4CA for ; Wed, 9 May 2007 11:49:15 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 48576-04 for ; Wed, 9 May 2007 11:49:11 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 9DEB39FA2F8 for ; Wed, 9 May 2007 11:49:11 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.1/8.14.1) with ESMTP id l49En8gH026774; Wed, 9 May 2007 10:49:08 -0400 (EDT) To: Peter Eisentraut cc: pgsql-performance@postgresql.org Subject: Re: Apparently useless bitmap scans In-reply-to: <200705091410.57312.peter_e@gmx.net> References: <200705091410.57312.peter_e@gmx.net> Comments: In-reply-to Peter Eisentraut message dated "Wed, 09 May 2007 14:10:57 +0200" Date: Wed, 09 May 2007 10:49:08 -0400 Message-ID: <26773.1178722148@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/195 X-Sequence-Number: 24585 Peter Eisentraut writes: > I'm wondering what it wants to achieve with these three index scans: See if you still get that with 8.2.4. choose_bitmap_and was fairly far out in left field before that :-( ... particularly for cases with partially redundant indexes available. regards, tom lane