Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id C23F963231A for ; Fri, 23 Jul 2010 19:12:56 -0300 (ADT) 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 77164-02 for ; Fri, 23 Jul 2010 22:12:48 +0000 (UTC) X-Greylist: delayed 00:09:43.925213 by SQLgrey-1.7.6 Received: from ironport2.lbl.gov (ironport2.lbl.gov [128.3.41.14]) by mail.postgresql.org (Postfix) with ESMTP id 6F50E632A5B for ; Fri, 23 Jul 2010 19:12:49 -0300 (ADT) X-Ironport-SBRS: 4.4 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AhgCADauSUzRVdS0kGdsb2JhbACTJIw9CBUBAQEBCQkMBxEDH8IchTYEhAU X-IronPort-AV: E=Sophos;i="4.55,250,1278313200"; d="scan'208";a="111955647" Received: from mail-px0-f180.google.com ([209.85.212.180]) by ironport2.lbl.gov with ESMTP; 23 Jul 2010 15:03:03 -0700 Received: by mail-px0-f180.google.com with SMTP id 3so5075656pxi.39 for ; Fri, 23 Jul 2010 15:03:03 -0700 (PDT) Received: by 10.115.58.4 with SMTP id l4mr6346915wak.16.1279922565775; Fri, 23 Jul 2010 15:02:45 -0700 (PDT) Received: from [128.3.60.152] (cox.lbl.gov [128.3.60.152]) by mx.google.com with ESMTPS id g4sm1144991wae.14.2010.07.23.15.02.43 (version=TLSv1/SSLv3 cipher=RC4-MD5); Fri, 23 Jul 2010 15:02:44 -0700 (PDT) Message-ID: <4C4A11CB.6040800@lbl.gov> Date: Fri, 23 Jul 2010 15:03:55 -0700 From: Gerald Fontenay Reply-To: gvfontenay@lbl.gov User-Agent: Thunderbird 1.5.0.5 (X11/20060815) MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: Strange explain on partitioned tables References: <4C47F8C8.10005@edd.fr> <4C484874.3060609@2ndquadrant.com> In-Reply-To: <4C484874.3060609@2ndquadrant.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-4.21 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201007/341 X-Sequence-Number: 39730 > The PostgreSQL partitioning system is aimed to support perhaps a > hundred inherited tables. You can expect to get poor performance on > queries if you create 1000 of them. Hi, Why is that you would expect poor performance for say 1000 or more? I have a ~1000 inherited tables and I don't see any significant slowdowns. I only ever access a single inherited table at a time though in this situation. I suppose I am using inheritance only for organization in this case... Thanks, Gerald