X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 76E5852839 for ; Tue, 17 May 2005 14:49:10 -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 54358-07 for ; Tue, 17 May 2005 17:48:59 +0000 (GMT) Received: from cougar.unisys.com.br (smtp2.unisys.com.br [200.220.0.118]) by svr1.postgresql.org (Postfix) with ESMTP id E6B1352807 for ; Tue, 17 May 2005 14:48:56 -0300 (ADT) Received: from [192.168.0.1] ([200.155.197.32]) by cougar.unisys.com.br ; Tue, 17 May 2005 14:48:52 -0300 EST Message-ID: <428A2E81.2060501@pobox.com> Date: Tue, 17 May 2005 14:48:49 -0300 From: Alain User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: pt-br, pt MIME-Version: 1.0 To: Sql-Postgre Subject: Re: Does Postgresql have a similar pseudo-column "ROWNUM" as References: <20050517170636.GC12405@phlogiston.dyndns.org> In-Reply-To: <20050517170636.GC12405@phlogiston.dyndns.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Rcpt-To: X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests= X-Spam-Level: X-Archive-Number: 200505/130 X-Sequence-Number: 21443 Andrew Sullivan escreveu: > On Thu, May 12, 2005 at 01:07:00PM -0600, Dennis.Jiang@thomson.com wrote: > >>Does Postgresql have a similar pseudo-column "ROWNUM" as Oracle? If >>so, we can write the following query: > > > No. What is the purpose of your query? You could use ORDER BY and > LIMIT..OFFSET to do what you want. I think. The problem is probably speed. I have done a lot of tests, and when OFFSET gets to a few thousands on a multimega-recs database, it gets very very slow... Is there any other to work around that? Alain