Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id 580C71337B61 for ; Fri, 11 Mar 2011 13:54:50 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 04680-01 for ; Fri, 11 Mar 2011 17:54:42 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mailout-de.gmx.net (mailout-de.gmx.net [213.165.64.23]) by mail.postgresql.org (Postfix) with SMTP id 58299133616B for ; Fri, 11 Mar 2011 13:54:42 -0400 (AST) Received: (qmail 1511 invoked by uid 0); 11 Mar 2011 17:54:40 -0000 Received: from 217.91.105.163 by www099.gmx.net with HTTP; Fri, 11 Mar 2011 18:54:39 +0100 (CET) Cc: pgsql-performance@postgresql.org Content-Type: text/plain; charset="utf-8" Date: Fri, 11 Mar 2011 18:54:39 +0100 From: "hans wulf" In-Reply-To: Message-ID: <20110311175439.6380@gmx.net> MIME-Version: 1.0 References: <20110311153205.6380@gmx.net> Subject: Re: ANTI-JOIN needs table, index scan not possible? To: Maciek Sakrejda X-Authenticated: #18544190 X-Flags: 0001 X-Mailer: WWW-Mail 6100 (Global Message Exchange) X-Priority: 3 X-Provags-ID: V01U2FsdGVkX19OMHwGih5OmNYdedp6j096Kfr+fxH9KcORiEzhNZ OqYbsorExP2yyti60pFMzuQlZEMTDvNTbyRA== Content-Transfer-Encoding: 8bit X-GMX-UID: uwgfDBB2fW47awSsbWRo5w5udmllcoV0 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-0.356 tagged_above=-10 required=5 tests=BAYES_00=-1.9, FREEMAIL_ENVFROM_END_DIGIT=1.553, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201103/123 X-Sequence-Number: 42802 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 :-( > Possibly because the index entries you're anti-joining against may > point to deleted tuples, so you would erroneously omit rows from the > join result if you skip the visibility check? > > --- > Maciek Sakrejda | System Architect | Truviso > > 1065 E. Hillsdale Blvd., Suite 215 > Foster City, CA 94404 > (650) 242-3500 Main > www.truviso.com -- Schon gehört? GMX hat einen genialen Phishing-Filter in die Toolbar eingebaut! http://www.gmx.net/de/go/toolbar