From oracle-l-bounce@freelists.org Tue Sep 20 12:01:15 2005 Return-Path: Received: from air891.startdedicated.com (root@localhost) by orafaq.com (8.12.10/8.12.10) with ESMTP id j8KH1FQg031526 for ; Tue, 20 Sep 2005 12:01:15 -0500 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 j8KH1A6H031508 for ; Tue, 20 Sep 2005 12:01:10 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id D18651EF1E9; Tue, 20 Sep 2005 12:00:58 -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 13196-07; Tue, 20 Sep 2005 12:00:58 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 59DA01EF1B9; Tue, 20 Sep 2005 12:00:58 -0500 (EST) X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C5BE04.81565D19" Subject: Index skip scan Date: Tue, 20 Sep 2005 12:58:20 -0400 Message-ID: <77A4D80DB2ADD74EB5D7F1D31626F0C0024F9461@usa0300ms03.na.xerox.net> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Index skip scan Thread-Index: AcW+BIDepXM96BakQv28RYDbDdmwbg== From: "Hameed, Amir" To: X-OriginalArrivalTime: 20 Sep 2005 16:58:22.0559 (UTC) FILETIME=[825396F0:01C5BE04] X-archive-position: 25698 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: Amir.Hameed@xerox.com Precedence: normal Reply-To: Amir.Hameed@xerox.com X-list: oracle-l X-Virus-Scanned: by amavisd-new-20030616-p9 (Debian) at avenirtech.net X-mailscan-MailScanner-Information: Please contact the ISP for more information X-mailscan-MailScanner: Found to be clean X-MailScanner-From: oracle-l-bounce@freelists.org X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on air891.startdedicated.com X-Spam-Status: No, hits=-4.5 required=5.0 tests=AWL,BAYES_00,HTML_MESSAGE autolearn=ham version=2.63 ------_=_NextPart_001_01C5BE04.81565D19 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Folks, Does anyone know that in order for the optimizer to choose "Index skip scan" on a concatenated index where the first column is not very selective but the second one is, approximately what type of selectivity on the leading column the Optimizer look for before deciding to take this route? Thanks Amir ------_=_NextPart_001_01C5BE04.81565D19 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Index skip scan

Folks,
Does anyone know that in order = for the optimizer to choose "Index skip scan" on a = concatenated index where the first column is not very selective but the = second one is, approximately what type of selectivity on the leading = column the Optimizer look for before deciding to take this = route?

Thanks
Amir

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