X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 9451DD864B for ; Tue, 30 Aug 2005 14:43:11 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 20731-01 for ; Tue, 30 Aug 2005 17:43:07 +0000 (GMT) Received: from mail.travelamericas.com (unknown [206.130.134.147]) by svr1.postgresql.org (Postfix) with SMTP id 99DFCD85C4 for ; Tue, 30 Aug 2005 14:43:05 -0300 (ADT) Received: (qmail 7310 invoked from network); 30 Aug 2005 17:43:06 -0000 Received: from unknown (HELO ?10.0.0.253?) (10.0.0.253) by verkiel.travelamericas.com with SMTP; 30 Aug 2005 17:43:06 -0000 Message-ID: <43149AA9.4080902@travelamericas.com> Date: Tue, 30 Aug 2005 10:43:05 -0700 From: Chris Travers User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Lenard, Rohan (Rohan)" Cc: "Thomas F. O'Connell" , pgsql-performance@postgresql.org Subject: Re: Need indexes on empty tables for good performance ? References: <2773CAC687FD5F4689F526998C7E4E5F489B7B@au3010avexu1.global.avaya.com> In-Reply-To: <2773CAC687FD5F4689F526998C7E4E5F489B7B@au3010avexu1.global.avaya.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.052 required=5 tests=[AWL=0.002, FORGED_RCVD_HELO=0.05] X-Spam-Level: X-Archive-Number: 200508/530 X-Sequence-Number: 14277 Lenard, Rohan (Rohan) wrote: > Actually the indexes on the child table do seem to get used - I just > wanted to make sure there was no penalty not having indexes on the > empty parent tables. > > You are right - the parent is the best way to get at the unknown > children ... Indexes are created in the inheritance process, iirc. However, index entries are not inherited, which means that index-based unique constraints don't properly get inherited. Best Wishes, Chris Travers Metatron Technology Consulting