From oracle-l-bounce@freelists.org Thu Apr 8 12:14:40 2004 Return-Path: Received: from air189.startdedicated.com (root@localhost) by orafaq.com (8.11.6/8.11.6) with ESMTP id i38HEeR04990 for ; Thu, 8 Apr 2004 12:14:40 -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 i38HEeo04985 for ; Thu, 8 Apr 2004 12:14:40 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 5CD5C6340FD; Thu, 8 Apr 2004 12:09:50 -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 17178-90; Thu, 8 Apr 2004 12:09:50 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 9527A6351A0; Thu, 8 Apr 2004 12:09:49 -0500 (EST) Received: with ECARTIS (v1.0.0; list oracle-l); Thu, 08 Apr 2004 12:08:37 -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 D198B634FBC for ; Thu, 8 Apr 2004 12:08:13 -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 17704-07 for ; Thu, 8 Apr 2004 12:08:13 -0500 (EST) Received: from woodstock.jcpenney.com (146-235-35-94-jcp.jcpenney.com [146.235.35.94]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 7104E636CF7 for ; Thu, 8 Apr 2004 12:07:24 -0500 (EST) Received: from i006.jcpenney.com (i006.jcpenney.com [10.33.181.215]) by woodstock.jcpenney.com (8.12.10+Sun/8.12.10) with ESMTP id i38HDh1w005925 for ; Thu, 8 Apr 2004 12:16:54 -0500 (CDT) Received: from rshamsudxp ([10.32.47.33]) by i006.jcpenney.com (iPlanet Messaging Server 5.2 HotFix 1.17 (built Jun 23 2003)) with ESMTPA id <0HVV009T63Y4NX@i006.jcpenney.com> for oracle-l@freelists.org; Thu, 08 Apr 2004 12:15:40 -0500 (CDT) Date: Thu, 08 Apr 2004 12:15:38 -0500 From: Riyaj Shamsudeen Subject: RE: [Q] what differtent between logical standby database and physical standby DB? In-reply-to: <019d01c41d88$3aedd780$0ea623d5@porgand> To: oracle-l@freelists.org Message-id: <005301c41d8d$1d3b8250$212f200a@rshamsudxp> MIME-version: 1.0 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Mailer: Microsoft Outlook, Build 10.0.3416 Content-type: text/plain Content-Transfer-Encoding: 8bit Importance: Normal X-Priority: 3 (Normal) X-MSMail-priority: Normal X-Disclaimer: Outbound Correspondence X-VirusScan: JCP virus scan detected no virus X-Virus-Scanned: by amavisd-new at freelists.org X-archive-position: 2790 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: rshamsud@jcpenney.com Precedence: normal Reply-To: oracle-l@freelists.org X-list: oracle-l X-Virus-Scanned: by amavisd-new at freelists.org Tanel Guess, I am not understanding the word "construction" applied towards a physical standby. Change vectors describe the changes at a lowest granular level and KCB layer( I think..) has to apply the change vectors directly to the data block buffer (of course, after reading the buffer if not present in the cache etc..etc). I don't understand what need to be constructed for the physical standby application. Are you refering to redo block checksum verification or something along those lines ? You also said parsing has to be done for the change vectors. Can you please help me understand that too ? I agree completely that lot more need to be done to reconstruct the SQL in the case of logical standby. Thanks a lot, Tanel! Riyaj "Re-yas" Shamsudeen Certified Oracle DBA -----Original Message----- From: oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] On Behalf Of Tanel Põder Sent: Thursday, April 08, 2004 11:41 AM To: oracle-l@freelists.org Subject: Re: [Q] what differtent between logical standby database and physical standby DB? > Um, in the physical standby case, aren't the archivelogs simply = > transferred to the standby server in their entirety? To the best of > my = knowledge, physical standby doesn't do logmining, right? It doesn't do logmining, but however, in both cases the changes have to be constructed from change vectors (and supplemental information) in redo records, the difference is that in logical apply scenario sql statements are constructed and passed to higher layer for sql processing, but in physical apply just datablocks are read and changes are applied to them directly (using kernel cache layer?). The point I was trying to make was, that in both cases you have to parse the redo records to get the changes, that way you'd detect corruptions equally in both cases as well... yes SQL apply ignores some of the redo vectors in logs but on the other hand, it requires additional, supplemental records for its operations... Tanel. ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- -- Attached file included as plaintext by Ecartis -- -- Desc: Signature The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. If the reader of this message is not the intended recipient, you are hereby notified that your access is unauthorized, and any review, dissemination, distribution or copying of this message including any attachments is strictly prohibited. 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