From oracle-l-bounce@freelists.org Mon Jan 24 14:37:31 2005 Return-Path: Received: from air891.startdedicated.com (root@localhost) by orafaq.com (8.12.10/8.12.10) with ESMTP id j0OKbVr9024651 for ; Mon, 24 Jan 2005 14:37:31 -0600 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air891.startdedicated.com (8.12.10/8.12.10) with ESMTP id j0OKbRem024626 for ; Mon, 24 Jan 2005 14:37:28 -0600 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 27389631CD; Mon, 24 Jan 2005 14:36:41 -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 30648-02; Mon, 24 Jan 2005 14:36:41 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 8D2A563257; Mon, 24 Jan 2005 14:36:40 -0500 (EST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding; b=SAlrWaU3GPMVycY/B3hEGiZPT+JSAIXUYWqWHno/r1s3RaGDXyDjoJLQ+XiSJ4PWvuNWZKzmgCaBIsfFUgsjQTYL+SpSq3VXbYI/4Z/hiBQrRrl5c9oXCqSaBMJFu9r1xxHovEv1OOayID5XJqWcwsaSGb9Nb8JCWvdEQ78Y+9c= Message-ID: <83a585ac05011614155036ea69@mail.gmail.com> Date: Mon, 24 Jan 2005 14:36:41 -0500 (EST) From: =?ISO-8859-1?Q?Alfonso_Le=F3n?= To: oracle-l@freelists.org Subject: does anybody recomends using dbms_stats.gather_schema_stats with for columnns size skewonly Mime-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit X-archive-position: 14851 X-ecartis-version: Ecartis v1.0.0 X-original-sender: aleon68@gmail.com Precedence: normal X-list: oracle-l X-OriginalArrivalTime: 16 Jan 2005 22:21:07.0500 (UTC) FILETIME=[ACB2D6C0:01C4FC19] X-archive-position: 15195 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: aleon68@gmail.com Precedence: normal Reply-To: aleon68@gmail.com X-list: oracle-l X-Virus-Scanned: by amavisd-new-20030616-p9 (Debian) at example.com X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on air891.startdedicated.com X-Spam-Status: No, hits=1.5 required=5.0 tests=AWL,DATE_IN_PAST_96_XX, FROM_ENDS_IN_NUMS autolearn=no version=2.60 X-Spam-Level: * X-Orig-Date: Sun, 16 Jan 2005 17:15:54 -0500 Hello: We are estimating statistics for each schema of our aplication using DBMS_STATS.GATHER_SCHEMA_STATS with method_opt FOR COLUMNS SIZE SKEWONLY (not using the ALL) and estimating with dbms_stats.auto_sample_size, options GATHER and CASCADE true. does this approach will estimate the estadistics for all columns using size 1 if the data is not skewed? would it do it only if needed? How does Oracle decide if the estadistics are needed or not? What is the recomended aproach to collect the statistics? Thanks in advance for your suggestions Alfonso Leon Guayaquil - Ecuador -- http://www.freelists.org/webpage/oracle-l -- http://www.freelists.org/webpage/oracle-l