From oracle-l-bounce@freelists.org Wed Apr 20 07:06:28 2005 Return-Path: Received: from air891.startdedicated.com (root@localhost) by orafaq.com (8.12.10/8.12.10) with ESMTP id j3KC6SGQ031356 for ; Wed, 20 Apr 2005 07:06:28 -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 j3KC6S4Z031352 for ; Wed, 20 Apr 2005 07:06:28 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 6849D1859EE; Wed, 20 Apr 2005 06:04:09 -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 17108-04; Wed, 20 Apr 2005 06:04:09 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id E1DBF185080; Wed, 20 Apr 2005 06:04:08 -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:content-disposition; b=QfN10cs7W9O4ZuUM/ssytsP8Bm1cOhDus8K6mqSc2Lstxhs+ltglY0ENelQTovdIW3CWKBkpOiuRwhbMbr9ox8cYWd6IQblHIA1YdBNFq/1mgOuQ57kZztjlq5wdF/hd4aUOw69nYrtxMzKvw1nkTd5eaArbu4pmZ4URZAB0tWI= Message-ID: Date: Wed, 20 Apr 2005 04:02:21 -0700 From: Ram K To: oracle-l@freelists.org Subject: Question on UNDO segment transition in an active database Mime-Version: 1.0 Content-type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Content-Disposition: inline X-archive-position: 18649 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: lambu999@gmail.com Precedence: normal Reply-To: lambu999@gmail.com X-list: oracle-l X-Virus-Scanned: by amavisd-new-20030616-p9 (Debian) at avenirtech.net X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on air891.startdedicated.com X-Spam-Status: No, hits=0.9 required=5.0 tests=AWL,FROM_ENDS_IN_NUMS autolearn=no version=2.63 Hi all, =20 I was reading Orafaq about Auto Undo management. According to it, one can have multiple UNDO tablespaces per database, but only one can be active at a given time (per instance). But, at any time the DBA can switch to a different undo tablespace by changing the UNDO_TABLESPACE parameter on-line (ALTER SYSTEM). =20 I am wondering how the switchover happens in a case where there are hundreds of active transactions. If there can be only one Undo tablespace where would the active transactions using the old Undo tablespace go during a switchover. Do they get switched over to the newer one (in the middle of the transaction) before the newer undo TS is brought online? Any points to consider while switching over when the system is experiencing high activity. --=20 Thanks, Ram. -- http://www.freelists.org/webpage/oracle-l