X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 8B89DD881E for ; Thu, 1 Sep 2005 19:34:44 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 43322-06 for ; Thu, 1 Sep 2005 22:34:43 +0000 (GMT) Received: from tigger.fuhr.org (tigger.fuhr.org [63.214.45.158]) by svr1.postgresql.org (Postfix) with ESMTP id DF480D8803 for ; Thu, 1 Sep 2005 19:34:41 -0300 (ADT) Received: from winnie.fuhr.org (winnie.fuhr.org [10.1.0.1]) by tigger.fuhr.org (8.13.3/8.13.3) with ESMTP id j81MYah3027983 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 1 Sep 2005 16:34:39 -0600 (MDT) (envelope-from mfuhr@winnie.fuhr.org) Received: from winnie.fuhr.org (localhost [127.0.0.1]) by winnie.fuhr.org (8.13.3/8.13.3) with ESMTP id j81MYahK044249; Thu, 1 Sep 2005 16:34:36 -0600 (MDT) (envelope-from mfuhr@winnie.fuhr.org) Received: (from mfuhr@localhost) by winnie.fuhr.org (8.13.3/8.13.3/Submit) id j81MYa5K044248; Thu, 1 Sep 2005 16:34:36 -0600 (MDT) (envelope-from mfuhr) Date: Thu, 1 Sep 2005 16:34:36 -0600 From: Michael Fuhr To: Matthew Sackman Cc: pgsql-performance@postgresql.org Subject: Re: Massive performance issues Message-ID: <20050901223436.GA44175@winnie.fuhr.org> References: <20050901174231.GE23970@pongo.lshift.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050901174231.GE23970@pongo.lshift.net> X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.005 required=5 tests=[AWL=0.005] X-Spam-Level: X-Archive-Number: 200509/34 X-Sequence-Number: 14342 On Thu, Sep 01, 2005 at 06:42:31PM +0100, Matthew Sackman wrote: > > "address_pc_top_index" btree (postcode_top) > "address_pc_top_middle_bottom_index" btree (postcode_top, > postcode_middle, postcode_bottom) > "address_pc_top_middle_index" btree (postcode_top, postcode_middle) This doesn't address the query performance problem, but isn't only one of these indexes necessary? The second one, on all three columns, because searches involving only postcode_top or only postcode_top and postcode_middle could use it, making the indexes on only those columns superfluous. Or am I missing something? -- Michael Fuhr