Received: from localhost (unknown [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id ACB489F95F4 for ; Wed, 10 Oct 2007 09:11:06 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 56779-05-2 for ; Wed, 10 Oct 2007 09:10:50 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id DEEE19F9709 for ; Wed, 10 Oct 2007 09:10:55 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.1/8.14.1) with ESMTP id l9ACAsG1013021; Wed, 10 Oct 2007 08:10:54 -0400 (EDT) To: "James Shaw" cc: pgsql-docs@postgresql.org Subject: Re: Possible mistake in 'Using EXPLAIN' section In-reply-to: References: Comments: In-reply-to "James Shaw" message dated "Wed, 10 Oct 2007 12:06:24 +0100" Date: Wed, 10 Oct 2007 08:10:54 -0400 Message-ID: <13020.1192018254@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200710/31 X-Sequence-Number: 4452 "James Shaw" writes: > The example given has "Seq Scan on tenk1 (cost=0.00..458.00" in the example, > but then says, "you will find out that tenk1 has 358 disk pages" and "the > cost is estimated at 358 page reads". Shouldn't this be 458 disk page > reads? No. Why did you stop reading in mid-sentence? regards, tom lane