Received: from localhost (unknown [200.46.204.183]) by developer.postgresql.org (Postfix) with ESMTP id 239022E006B for ; Tue, 17 Jun 2008 10:34:43 -0300 (ADT) Received: from developer.postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 83040-04-7 for ; Tue, 17 Jun 2008 10:34:24 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from ds528.dedicated.turbodns.co.uk (ds528.dedicated.turbodns.co.uk [81.21.72.118]) by developer.postgresql.org (Postfix) with ESMTP id B893D2E00F0 for ; Tue, 17 Jun 2008 10:30:28 -0300 (ADT) Received: (qmail 67544 invoked from network); 17 Jun 2008 13:30:25 -0000 Received: from howardnews@selestial.com by ds528.dedicated.turbodns.co.uk by uid 1005 with qmail-scanner-1.22 ( Clear:RC:1(62.3.231.11):. Processed in 0.022699 secs); 17 Jun 2008 13:30:25 -0000 Received: from unknown (HELO ?10.202.6.101?) (selestial-howard.cole@62.3.231.11) by ds528.dedicated.turbodns.co.uk with SMTP; 17 Jun 2008 13:30:25 -0000 Message-ID: <4857BBF7.7070909@selestial.com> Date: Tue, 17 Jun 2008 14:28:23 +0100 From: Howard Cole User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: Tsearch2 Initial Search Speed References: <4856A91F.1020001@selestial.com> <200806161124.57543@hal.medialogik.com> <485789C1.3000803@selestial.com> <485797D4.7010201@selestial.com> <48579EB1.8050403@selestial.com> <4857A739.5020800@selestial.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200806/69 X-Sequence-Number: 30419 > Actually, the index returns page numbers in the table on disc which > may contain one or more rows that are relevant. Postgres has to fetch > the whole row to find out the email_id and any other information, > including whether the row is visible in your current transaction > (concurrency control complicates it all). Just having a page number > isn't much use to you! > > Matthew > I learn something new every day. Thanks Matthew.