X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id 7D5409DCB44 for ; Thu, 23 Mar 2006 09:24:50 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 27001-07 for ; Thu, 23 Mar 2006 09:24:53 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from mx1.surnet.cl (mx1.surnet.cl [216.155.73.180]) by postgresql.org (Postfix) with ESMTP id 014CE9DCA89 for ; Thu, 23 Mar 2006 09:24:45 -0400 (AST) Received: from unknown (HELO cluster.surnet.cl) ([216.155.73.165]) by mx1.surnet.cl with ESMTP; 23 Mar 2006 09:24:49 -0400 X-IronPort-AV: i="4.03,122,1141614000"; d="scan'208"; a="48387626:sNHT78612848" Received: from alvh.no-ip.org (201.221.200.224) by cluster.surnet.cl (7.0.043) (authenticated as alvherre@surnet.cl) id 43A978FD00BAA250; Thu, 23 Mar 2006 09:24:49 -0400 Received: by alvh.no-ip.org (Postfix, from userid 1000) id 2587CC3A2D0; Thu, 23 Mar 2006 09:24:49 -0400 (CLT) Date: Thu, 23 Mar 2006 09:24:49 -0400 From: Alvaro Herrera To: Theo Kramer Cc: pgsql-performance@postgresql.org Subject: Re: Indexes with descending date columns Message-ID: <20060323132448.GB4881@surnet.cl> Mail-Followup-To: Theo Kramer , pgsql-performance@postgresql.org References: <200603170625.k2H6PJ926955@pillette.com> <1143112188.2810.27.camel@theo-laptop.int.coza.net.za> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1143112188.2810.27.camel@theo-laptop.int.coza.net.za> User-Agent: Mutt/1.5.11+cvs20060126 X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=1.577 required=5 tests=[AWL=-0.342, DNS_FROM_RFC_ABUSE=0.479, DNS_FROM_RFC_POST=1.44] X-Spam-Score: 1.577 X-Spam-Level: * X-Archive-Number: 200603/470 X-Sequence-Number: 17907 Theo Kramer wrote: > All good input - thanks, however, before I start messing with my stuff > which I know will be complex - some questions to any of the developers > on the list. > > i Is it feasible to extend index creation to support descending > columns? ... this is supported on other commercial and non > commercial databases, but I do not know if this is a SQL standard. This can be done. You need to create an operator class which specifies the reverse sort order (i.e. reverse the operators), and then use it in the new index. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.