Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 7B2BC1337B98 for ; Thu, 7 Oct 2010 04:51:22 -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 73212-05 for ; Thu, 7 Oct 2010 07:51:15 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from exprod7og110.obsmtp.com (exprod7og110.obsmtp.com [64.18.2.173]) by mail.postgresql.org (Postfix) with SMTP id 915B7133616B for ; Thu, 7 Oct 2010 04:51:14 -0300 (ADT) Received: from source ([209.85.215.47]) by exprod7ob110.postini.com ([64.18.6.12]) with SMTP ID DSNKTK178u8y8ckNvQjondiDGOZ1VLDfGH5U@postini.com; Thu, 07 Oct 2010 00:51:15 PDT Received: by ewy7 with SMTP id 7so162453ewy.20 for ; Thu, 07 Oct 2010 00:51:13 -0700 (PDT) Received: by 10.213.35.77 with SMTP id o13mr1344908ebd.11.1286437872173; Thu, 07 Oct 2010 00:51:12 -0700 (PDT) Received: from [192.168.1.183] (dsl-hkibrasgw2-ff7ac300-240.dhcp.inet.fi [88.195.122.240]) by mx.google.com with ESMTPS id v59sm2974107eeh.16.2010.10.07.00.51.10 (version=TLSv1/SSLv3 cipher=RC4-MD5); Thu, 07 Oct 2010 00:51:10 -0700 (PDT) Message-ID: <4CAD7BED.4050009@enterprisedb.com> Date: Thu, 07 Oct 2010 10:51:09 +0300 From: Heikki Linnakangas User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; fi-FI; rv:1.9.1.12) Gecko/20100913 Icedove/3.0.7 MIME-Version: 1.0 To: Simon Riggs CC: Vincenzo Romano , pgsql-hackers@postgresql.org Subject: Re: On Scalability References: <1280423526.8613.36.camel@jd-desktop.unknown.charter.com> <1280425184.8613.41.camel@jd-desktop.unknown.charter.com> <1280427410.8613.44.camel@jd-desktop.unknown.charter.com> <4CAD769D.9090301@enterprisedb.com> <1286437290.2304.192.camel@ebony> In-Reply-To: <1286437290.2304.192.camel@ebony> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-4.2 tagged_above=-5 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3 X-Spam-Level: X-Archive-Number: 201010/423 X-Sequence-Number: 171463 On 07.10.2010 10:41, Simon Riggs wrote: > On Thu, 2010-10-07 at 10:28 +0300, Heikki Linnakangas wrote: > >> constraint exclusion of CHECK constraints on the partitions is >> exponential > > Constraint exclusion is linear with respect to number of partitions. > Why do you say exponential? For some reason I thought the planner needs to check the constraints of the partitions against each other, but you're right, clearly that's not the case. Linear it is. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com