Received: from maia.hub.org (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 215C46329B4 for ; Thu, 4 Mar 2010 16:53:42 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 45025-04 for ; Thu, 4 Mar 2010 20:53:27 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-pw0-f46.google.com (mail-pw0-f46.google.com [209.85.160.46]) by mail.postgresql.org (Postfix) with ESMTP id 5F14F63253A for ; Thu, 4 Mar 2010 16:53:31 -0400 (AST) Received: by pwj8 with SMTP id 8so1920774pwj.19 for ; Thu, 04 Mar 2010 12:53:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:from:date:x-google-sender-auth:message-id:subject:to:cc :content-type; bh=bTCdf4LZWKUc65uiY5q/de4uqiKgLRvJc3AxMJeD4wU=; b=GjHa+sTb2fJZVt0xJ6uYW2AXtoQAq2eH3Bm/naBYhQ46CRw5I5iEQ8wnFRdzpm9Kdk 8O+9KQwDmz1YWzY/sHxChsAIAegBv+71gCEQc4Uid2lCtQGgGqaUTcKMvGiafXfOzRcR msY/nym7L+l8s/faC8sJ833DVWDPIaEoVCwQI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type; b=GH6BLSm8gTpCauGhzLeUp2HeROIWz/Rgo+5ey6S+oGoSBYSh/2CfFjRDR0wcKmQnl2 KrqFAjUl5lysnSKASzWgmD1j6v4lULYkcR6ltr5Ow+zg+CRofjFmrwLqcx85/cn16y3q Yebr5r5l/srlPiQhYxbaSKKK7Vd8ZGjuWBBJ8= MIME-Version: 1.0 Received: by 10.141.108.9 with SMTP id k9mr5541833rvm.226.1267736010098; Thu, 04 Mar 2010 12:53:30 -0800 (PST) In-Reply-To: <4B901488.6080502@fmed.uba.ar> References: <20100304200913.GA24865@apartia.fr> <4B901488.6080502@fmed.uba.ar> From: Greg Stark Date: Thu, 4 Mar 2010 20:53:10 +0000 X-Google-Sender-Auth: 3e0a89f75baf65d8 Message-ID: <407d949e1003041253g1812b85bhe8ce0fbd7b1f7159@mail.gmail.com> Subject: Re: an aggregate to return max() - 1 value? To: Gerardo Herzig Cc: pgsql-sql@postgresql.org Content-Type: text/plain; charset=ISO-8859-1 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.476 tagged_above=-10 required=5 tests=AWL=0.123, BAYES_00=-2.599 X-Spam-Level: X-Archive-Number: 201003/32 X-Sequence-Number: 33739 SELECT col FROM tab ORDER BY col DESC OFFSET 1 LIMIT 1 In 8.4 OLAP window functions provide more standard and flexibility method but in this case it wouldn't perform as well: postgres=# select i from (select i, rank() over (order by i desc) as r from i) as x where r = 2; i ---- 99 (1 row) postgres=# select i from (select i, dense_rank() over (order by i desc) as r from i) as x where r = 2; i ---- 99 (1 row) -- greg