Received: from localhost (unknown [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 095002E003F for ; Sat, 8 Dec 2007 16:46:26 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 32506-07 for ; Sat, 8 Dec 2007 16:46:18 -0400 (AST) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id D20B42E0088 for ; Sat, 8 Dec 2007 16:46:20 -0400 (AST) 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 lB8KkJSQ015506; Sat, 8 Dec 2007 15:46:19 -0500 (EST) To: Mark Mielke cc: pgsql-performance@postgresql.org Subject: Re: Combining two bitmap scans out performs a single regular index scan? In-reply-to: <475AD1E8.7000304@mark.mielke.cc> References: <475AD1E8.7000304@mark.mielke.cc> Comments: In-reply-to Mark Mielke message dated "Sat, 08 Dec 2007 12:18:32 -0500" Date: Sat, 08 Dec 2007 15:46:19 -0500 Message-ID: <15505.1197146779@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200712/108 X-Sequence-Number: 27924 Mark Mielke writes: > To find records after a certain time, I must do one of: > select * from icpric where audtdate > ? or (audtdate = ? and > audttime > ?) In recent releases (at least 8.2, don't remember about 8.1), a row comparison is what you want: WHERE (auddate, adttime) > (?, ?) regards, tom lane