From oracle-l-bounce@freelists.org Thu Sep 2 20:38:46 2004 Return-Path: Received: from air189.startdedicated.com (root@localhost) by orafaq.com (8.11.6/8.11.6) with ESMTP id i831ck618170 for ; Thu, 2 Sep 2004 20:38:46 -0500 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air189.startdedicated.com (8.11.6/8.11.6) with ESMTP id i831ckI18165 for ; Thu, 2 Sep 2004 20:38:46 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 658AB72E673; Thu, 2 Sep 2004 20:23:22 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 23496-26; Thu, 2 Sep 2004 20:23:22 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 227A473087F; Thu, 2 Sep 2004 19:58:34 -0500 (EST) Received: with ECARTIS (v1.0.0; list oracle-l); Thu, 02 Sep 2004 19:56:51 -0500 (EST) X-Original-To: oracle-l@freelists.org Delivered-To: oracle-l@freelists.org Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 7EA5D72D79E for ; Thu, 2 Sep 2004 19:32:10 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 04433-57 for ; Thu, 2 Sep 2004 19:32:10 -0500 (EST) Received: from shasta.watchmark.com (shasta.watchmark.com [63.117.8.71]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id C678572E8DE for ; Thu, 2 Sep 2004 19:14:43 -0500 (EST) Received: from sapphire.wa.watchmark.com (sapphire.wa.watchmark.com [63.117.8.105]) by shasta.watchmark.com (8.11.7p1+Sun/8.11.0.Beta3) with ESMTP id i830Gh218405 for ; Thu, 2 Sep 2004 17:16:43 -0700 (PDT) Date: Thu, 2 Sep 2004 17:16:43 -0700 (PDT) From: Steve Rospo X-X-Sender: srospo@sapphire.wa.watchmark.com To: Oracle Discussion List Subject: Re: Count(*) not doing a FTS?? In-Reply-To: <9177895d04090208207368b7bc@mail.gmail.com> Message-ID: MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII X-Virus-Scanned: by amavisd-new at freelists.org Content-Transfer-Encoding: 8bit X-archive-position: 9015 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: srospo@watchmark.com Precedence: normal Reply-To: oracle-l@freelists.org X-list: oracle-l X-Virus-Scanned: by amavisd-new at freelists.org Did your instructor say this with a straight face? There's no such voodoo as a rowcount in a segment header. The two ways you can do it are a FTS or fast full scan of a not null index. There are other more exotic ways (materialized view) but nothing involving the segment header, that I know of. In this case providing a counter-example is actually easier, have the instructor provide an execution plan where that shows something other than a FTS or index FFS. S- On Thu, 2 Sep 2004, rjamya wrote: > I am sitting in a class and instructor told us that count(*) reads > rowcount from segment header in some (or most?) cases rather than > doign the good ol' FTS. He can't remember exact details, so this email > .... > > is it true? Which version was this introduced? Someone has a > reproducible test case? > > Thanks in advance > Raj > ------------------------------ > --- > To unsubscribe - mailto:oracle-l-request@freelists.org&subject=unsubscribe > To read recent messages - http://freelists.org/archives/oracle-l/09-2004 > --- To unsubscribe - mailto:oracle-l-request@freelists.org&subject=unsubscribe To read recent messages - http://freelists.org/archives/oracle-l/09-2004