Received: (qmail 11145 invoked from network); 11 Nov 2010 01:57:30 -0600 Received: from freelists-180.iquest.net (HELO turing.freelists.org) (206.53.239.180) by static-ip-85-25-126-90.inaddr.intergenia.de with SMTP; 11 Nov 2010 01:57:25 -0600 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 9139BD500AB; Thu, 11 Nov 2010 02:57:23 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=freelists.org; s=turing; t=1289462243; bh=e85PpQ+hGidd7F6rSKAU8Iq/lzrO2XpU+W31hWkj ibI=; h=Message-ID:Date:From:MIME-Version:To:Subject:References: In-Reply-To:Content-Type:Content-Transfer-Encoding:Sender:Reply-To: List-help:List-unsubscribe:List-Id:List-subscribe:List-owner: List-post:List-archive; b=SSjDnmF2Nf++4J7ZY2757qqEtOc+v6+wJDIRBdVt JWpldzwmO3KiI/XCEh69TgR5QgDI2A18pwgbszMxT+8fvIpSu7pADVfH2Aso1doK6nb vBPz1prHegDXODysZpASux8ANQ1+9kPVGRVorIgzQru2rXMOnIdaQkVq5ynfu9y8= X-Virus-Scanned: Debian amavisd-new at localhost.localdomain Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id u6TXtEbztXeG; Thu, 11 Nov 2010 02:57:23 -0500 (EST) Received: from turing.freelists.org (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 48BDAD50089; Thu, 11 Nov 2010 02:56:40 -0500 (EST) Received: with ECARTIS (v1.0.0; list oracle-l); Thu, 11 Nov 2010 02:55:59 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id BE3D3D4F22C for ; Thu, 11 Nov 2010 02:55:58 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3D3FmqQSdt5W for ; Thu, 11 Nov 2010 02:55:58 -0500 (EST) Received: from smtp-out2.blueyonder.co.uk (smtp-out2.blueyonder.co.uk [195.188.213.5]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id B32B9D4EE8A for ; Thu, 11 Nov 2010 02:55:57 -0500 (EST) Received: from [172.23.144.249] (helo=asmtp-out5.blueyonder.co.uk) by smtp-out2.blueyonder.co.uk with esmtp (Exim 4.52) id 1PGS0b-0001eT-Jy for oracle-l@freelists.org; Thu, 11 Nov 2010 07:55:49 +0000 Received: from [82.35.20.102] (helo=starbase-2.local) by asmtp-out5.blueyonder.co.uk with esmtp (Exim 4.52) id 1PGS0C-00030s-0t for oracle-l@freelists.org; Thu, 11 Nov 2010 07:55:24 +0000 Message-ID: <4CDBA16B.7090109@williamrobertson.net> Date: Thu, 11 Nov 2010 07:55:23 +0000 From: William Robertson User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.12) Gecko/20101027 Thunderbird/3.1.6 ThunderBrowse/3.3.2 MIME-Version: 1.0 To: ORACLE-L Subject: Re: AW: Dynamic sampling References: ,<4CDB9505.2010708@williamrobertson.net> <09011014EB621E4CBC2536B62A1B6407A909@SMXC001.trivadis.com> In-Reply-To: <09011014EB621E4CBC2536B62A1B6407A909@SMXC001.trivadis.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-archive-position: 32498 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-to: oracle-l-bounce@freelists.org X-original-sender: william@williamrobertson.net Precedence: normal Reply-To: william@williamrobertson.net List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: oracle-l X-List-ID: oracle-l List-subscribe: List-owner: List-post: List-archive: X-list: oracle-l Well, yes, that could happen if the dynamic sampling level was high and the query was rarely executed or a one-off. Neither of these is necessarily the case when you see a long execution plan and a mention of dynamic sampling in the footnote. -------- Original Message -------- Subject: AW: Dynamic sampling From: Petr Novak To: william@williamrobertson.net , ORACLE-L Date: 11/11/2010 07:40 > But what if the the dynamic sampling consumes more resources the the statements itself ? I have also seen such database. It is better to have correct statistics. > > Best Regards, > Petr > ________________________________________ > Von: oracle-l-bounce@freelists.org [oracle-l-bounce@freelists.org]" im Auftrag von"William Robertson [william@williamrobertson.net] > Gesendet: Donnerstag, 11. November 2010 08:02 > Bis: ORACLE-L > Betreff: Re: Dynamic sampling > > What have the number of lines in the plan and the predicates section got to do with dynamic sampling? Are you saying dynamic sampling is a bad thing? It seems like an excellent feature to me. > > William Robertson > > -------- Original Message -------- > Subject: Dynamic sampling > From: Hemant K Chitale > To: ORACLE-L > Date: 11/11/2010 03:43 >> >> AARGH! >> >> What you do when DBMS_XPLAN.DISPLAY_CURSOR shows a 190 line Plan with 205 entries in the Predicates section and then adds "dynamic sampling used". >> >> Just venting my frustration. -- http://www.freelists.org/webpage/oracle-l