X-Original-To: pgsql-hackers-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id ABE70D1B344 for ; Wed, 4 Aug 2004 03:04:31 -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 23077-03 for ; Wed, 4 Aug 2004 06:04:10 +0000 (GMT) Received: from www.postgresql.com (www.postgresql.com [200.46.204.209]) by svr1.postgresql.org (Postfix) with ESMTP id 9D624D1B34A for ; Wed, 4 Aug 2004 03:02:44 -0300 (ADT) Received: from stark.xeocode.com (gsstark.mtl.istop.com [66.11.160.162]) by www.postgresql.com (Postfix) with ESMTP id 39C01CF4D3D for ; Wed, 4 Aug 2004 00:33:58 -0300 (ADT) Received: from localhost ([127.0.0.1] helo=stark.xeocode.com) by stark.xeocode.com with smtp (Exim 3.36 #1 (Debian)) id 1BsCPU-00088g-00; Tue, 03 Aug 2004 23:25:48 -0400 To: Bruce Momjian Cc: Greg Stark , pgsql-hackers@postgresql.org Subject: Re: TODO Items References: <200408040215.i742Fdt08424@candle.pha.pa.us> In-Reply-To: <200408040215.i742Fdt08424@candle.pha.pa.us> From: Greg Stark Organization: The Emacs Conspiracy; member since 1992 Date: 03 Aug 2004 23:25:47 -0400 Message-ID: <87brhrmvno.fsf@stark.xeocode.com> Lines: 22 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.0 tagged_above=0.0 required=5.0 tests= X-Spam-Level: X-Archive-Number: 200408/161 X-Sequence-Number: 57133 Bruce Momjian writes: > > . Allow multi-column indexes to be used to optimize row-value expressions. Ie, > > allow a btree index on a,b to be used to execute an expression like (a,b) < > > (x,y). > > I have not heard of any of those so I have not been actively excluding > them from the TODO list. However, I need someone with optimizer > experience to make a recommendation. Well the row-value expression stuff comes out of a discussion just this week. You could check messages on pgsql-performance with the subject "[PERFORM] best way to fetch next/prev record based on index". In particular Tom's messages from Wednesday the 28th might be relevant. The optimization in the first one came up in a conversation that was quite a bit older. I don't have that thread saved. It seems like an obvious optimization if it can be done efficiently. -- greg