Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id BD9861337B69 for ; Fri, 11 Mar 2011 18:16:12 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 85224-01 for ; Fri, 11 Mar 2011 22:16:05 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mh7.mail.rice.edu (mh7.mail.rice.edu [128.42.199.46]) by mail.postgresql.org (Postfix) with ESMTP id 368CE1337B61 for ; Fri, 11 Mar 2011 18:16:05 -0400 (AST) Received: from mh7.mail.rice.edu (localhost.localdomain [127.0.0.1]) by mh7.mail.rice.edu (Postfix) with ESMTP id CCA0D28FCF1; Fri, 11 Mar 2011 16:16:04 -0600 (CST) X-Virus-Scanned: by amavis-2.6.4 at mh7.mail.rice.edu, auth channel Received: from mh7.mail.rice.edu ([127.0.0.1]) by mh7.mail.rice.edu (mh7.mail.rice.edu [127.0.0.1]) (amavis, port 10026) with ESMTP id yvEFw0TVsBQi; Fri, 11 Mar 2011 16:16:04 -0600 (CST) X-SMTP-Auth: no X-SMTP-Auth: no X-SMTP-Auth: no Received: from aart.is.rice.edu (aart.is.rice.edu [168.7.56.48]) by mh7.mail.rice.edu (Postfix) with ESMTP id 999DD28FCD8; Fri, 11 Mar 2011 16:16:04 -0600 (CST) Received: by aart.is.rice.edu (Postfix, from userid 18612) id 069CA2D5A6; Fri, 11 Mar 2011 16:16:03 -0600 (CST) Date: Fri, 11 Mar 2011 16:16:03 -0600 From: Kenneth Marshall To: hans wulf Cc: Maciek Sakrejda , pgsql-performance@postgresql.org Subject: Re: ANTI-JOIN needs table, index scan not possible? Message-ID: <20110311221603.GI8169@aart.is.rice.edu> References: <20110311153205.6380@gmx.net> <20110311175439.6380@gmx.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110311175439.6380@gmx.net> User-Agent: Mutt/1.5.16 (2007-06-09) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.91 tagged_above=-10 required=5 tests=BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201103/124 X-Sequence-Number: 42803 On Fri, Mar 11, 2011 at 06:54:39PM +0100, hans wulf wrote: > Thanks for the answer. > > so there's no way around this problem? A nice index bitmap merge thing would be super fast. Big table ANTI JOIN queries with only a few results expected, are totally broken, if this is true. > > This way the query breaks my neck. This is a massive downside of postgres which makes this kind of query impossible. Mysql gives you the answer in a few seconds :-( > > Super! I am glad that MySQL can meet your needs. No software is perfect and you should definitely chose based on your use-case. Regards, Ken