X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 8B226528BE for ; Mon, 6 Jun 2005 15:34:17 -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 68969-02 for ; Mon, 6 Jun 2005 18:34:07 +0000 (GMT) Received: from tigger.fuhr.org (tigger.fuhr.org [63.214.45.158]) by svr1.postgresql.org (Postfix) with ESMTP id 49C6B52864 for ; Mon, 6 Jun 2005 15:34:04 -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 j56IXeXY054916 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 6 Jun 2005 12:33:43 -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 j56IXeWF038958; Mon, 6 Jun 2005 12:33:40 -0600 (MDT) (envelope-from mfuhr@winnie.fuhr.org) Received: (from mfuhr@localhost) by winnie.fuhr.org (8.13.3/8.13.3/Submit) id j56IXe5L038957; Mon, 6 Jun 2005 12:33:40 -0600 (MDT) (envelope-from mfuhr) Date: Mon, 6 Jun 2005 12:33:40 -0600 From: Michael Fuhr To: Tobias Brox Cc: Jeffrey Tenny , pgsql-performance@postgresql.org Subject: Re: Need help to decide Mysql vs Postgres Message-ID: <20050606183340.GA38889@winnie.fuhr.org> References: <42A470FA.1080001@comcast.net> <20050606172508.GB8451@tobias.nordicbet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050606172508.GB8451@tobias.nordicbet.com> X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.005 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200506/130 X-Sequence-Number: 12767 On Mon, Jun 06, 2005 at 08:25:08PM +0300, Tobias Brox wrote: > [Jeffrey Tenny - Mon at 11:51:22AM -0400] > > There are some pitfalls to pgsql though, especially for existing SQL > > code using MAX and some other things which can really be blindsided > > (performance-wise) by pgsql if you don't use the workarounds. > > Yes, I discovered that - "select max(num_attr)" does a full table scan even > if the figure can be found easily through an index. PostgreSQL 8.1 will be able to use indexes for MIN and MAX. http://archives.postgresql.org/pgsql-committers/2005-04/msg00163.php http://archives.postgresql.org/pgsql-committers/2005-04/msg00168.php -- Michael Fuhr http://www.fuhr.org/~mfuhr/