Return-Path: Delivered-To: 2-oracle-l@orafaq.com Received: (qmail 9598 invoked from network); 7 Jul 2008 12:29:31 -0500 Received: from freelists-180.iquest.net (HELO turing.freelists.org) (206.53.239.180) by air964.startdedicated.com with SMTP; 7 Jul 2008 12:29:31 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id AED9F8794A9; Mon, 7 Jul 2008 13:29:31 -0400 (EDT) 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 09498-01; Mon, 7 Jul 2008 13:29:31 -0400 (EDT) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id F304A879479; Mon, 7 Jul 2008 13:29:30 -0400 (EDT) Received: with ECARTIS (v1.0.0; list oracle-l); Mon, 07 Jul 2008 12:50:15 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 980EB878BF1 for ; Mon, 7 Jul 2008 12:50:15 -0400 (EDT) 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 01507-01 for ; Mon, 7 Jul 2008 12:50:15 -0400 (EDT) Received: from rn-out-0910.google.com (rn-out-0910.google.com [64.233.170.191]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 41D7F878A6E for ; Mon, 7 Jul 2008 12:50:14 -0400 (EDT) Received: by rn-out-0910.google.com with SMTP id v46so451234rnb.9 for ; Mon, 07 Jul 2008 09:50:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type:references; bh=adFbNy1VT4rETs6Om27CiKQLPbuE2XFZhKj3+WfA5Vo=; b=Ex72LO9Z7G1IiWgc79VPGlANtNl8IzFipxDEhJRT2aFq4avZrMy8nKv1XmOUlouE2O fLdifIEIxavm2Uozt354Gjya3x12SU/NloZMmCKW0M3ShEmSecn0Uau+qOr0e/cvebHy bttb14il+HhxjRvWqtEBtBHteloeAGrodefgs= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:references; b=N1AAreIuZEiYL4yHYUUXD5TY68dMxigG/HhsnohMsgHReLGAZ7RgPLSNbpz7W2URO6 lL/P5aCh1WcEDdKN0vQ4UOAdOrZIuCndNGsDA3aioRgZGTsSM19sUuVXGILYCcf7fClV HEiWin1PF8sO1UobKeWe7C88AR+GvFg4MJUbA= Received: by 10.150.191.10 with SMTP id o10mr8543577ybf.56.1215449413761; Mon, 07 Jul 2008 09:50:13 -0700 (PDT) Received: by 10.150.199.11 with HTTP; Mon, 7 Jul 2008 09:50:13 -0700 (PDT) Message-ID: Date: Mon, 7 Jul 2008 11:50:13 -0500 From: "John Smith" To: "Hemant K Chitale" Subject: Re: no archivelog incomplete recovery? Cc: oracle-l@freelists.org In-Reply-To: <200807071501.m67F1iLH002985@smtp42.singnet.com.sg> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_22051_30739877.1215449413777" References: <200807071501.m67F1iLH002985@smtp42.singnet.com.sg> X-archive-position: 9338 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-to: oracle-l-bounce@freelists.org X-original-sender: john40855@gmail.com Precedence: normal Reply-to: john40855@gmail.com 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 X-Virus-Scanned: Debian amavisd-new at localhost.localdomain ------=_Part_22051_30739877.1215449413777 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline So in effect, it is a trick question because the recovery will only be to the state at the last full backup, even if they do call it 'recovery'? Since no archived logs will be available? On Mon, Jul 7, 2008 at 10:01 AM, Hemant K Chitale wrote: > > The keywords > "how to recover from a lost active online redo log in noarchivelog mode." > > is ACTIVE ! > > As the database is in NOARCHIVELOG, the only way a redo log could be > ACTIVE would be if a Checkpoint hasn't been completed. > [had the lost online redo log been an Inactive one, you wouldn't have > needed to do a Restore AT ALL, provided that you knew what to do !]. > > The only option is to Restore the last Consistent Backup. IF the > Consistent Backup included the Online Redo Logs, then you do not need to > RESETLOGS. If , however, the DBA had followed the advice of most "experts" > and the documentation and did not backup his Online Redo Logs [in his > Consistent Cold Backup of a NoArchiveLog database] you would HAVE to do a > RESETLOGS. > > (having said that, I guess it should be obvious that I don't agree with > most "experts" and the documentation that you should NEVER backup the Online > Redo Logs. This is one of the scenarios where a backup of the Online Redo > Logs [in a Consistent Cold Backup] would make an OPEN less "uncomfortable" ! > > But coming back to the scenario provided in your test : Although a > RESETLOGS would be adviced, a RECOVER DATABASE wouldn't be needed at all. > The sequence would be : > a. Restore Consistent Backup. > b. Verify if it included Online Redo Logs. If if did not include the > Online Redo Logs, go to step e. > c. STARTUP {ie, the same as STARTUP MOUNT; ALTER DATABASE OPEN > (normal)} in sqlplus / as sysdba > d. exit from sqlplus prompt and get a pay raise > e. STARTUP MOUNT ; ALTER DATABASE OPEN RESETLOGS in sqlplus / as sysdba > > Hemant K Chitale > > > At 07:57 AM Monday, John Smith wrote: > >> I am studying for the OCP, and one of the practice test questions is how >> to recover from a lost active online redo log in noarchivelog mode. the >> answer they give is to restore a consistent backup, startup in mount mode, >> perform a cancel based recovery, and open with resetlogs. >> >> Is that answer correct? I didnt think you could do a recovery if you >> arent in archivelog mode. >> > > > Hemant K Chitale > http://hemantoracledba.blogspot.com > > "A 'No' uttered from the deepest conviction is better than a 'Yes' merely > uttered to please, or worse, to avoid trouble." > Mohandas Gandhi Quotes : > http://www.brainyquote.com/quotes/authors/m/mohandas_gandhi.html > > ------=_Part_22051_30739877.1215449413777 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline So in effect, it is a trick question because the recovery will only be to the state at the last full backup, even if they do call it 'recovery'?  Since no archived logs will be available?

On Mon, Jul 7, 2008 at 10:01 AM, Hemant K Chitale <hkchital@singnet.com.sg> wrote:

The keywords

"how to recover from a lost active online redo log in noarchivelog mode."

is ACTIVE !

As the database is in NOARCHIVELOG,  the only way a redo log could be ACTIVE would be if a Checkpoint hasn't been completed.
[had the lost online redo log been an Inactive one, you wouldn't have needed to do a Restore AT ALL, provided that you knew what to do !].

The only option is to Restore the last Consistent Backup.  IF the Consistent Backup included the Online Redo Logs, then you do not need to RESETLOGS.  If , however, the DBA had followed the advice of most "experts" and the documentation and did not backup his Online Redo Logs  [in his Consistent Cold Backup of a NoArchiveLog database] you would HAVE to do a RESETLOGS.

(having said that, I guess it should be obvious that I don't agree with most "experts" and the documentation that you should NEVER backup the Online Redo Logs.  This is one of the scenarios where a backup of the Online Redo Logs [in a Consistent Cold Backup] would make an OPEN less "uncomfortable" !

But coming back to the scenario provided in your test :  Although a RESETLOGS would be adviced, a RECOVER DATABASE wouldn't be needed at all.
  The sequence would be :
 a.  Restore Consistent Backup.
 b.  Verify if it included Online Redo Logs.  If if did not include the Online Redo Logs, go to step e.
 c.  STARTUP    {ie, the same as STARTUP MOUNT; ALTER DATABASE OPEN  (normal)}  in sqlplus / as sysdba
 d.  exit from sqlplus prompt and get a pay raise
 e.  STARTUP MOUNT ; ALTER DATABASE OPEN RESETLOGS  in sqlplus / as sysdba

Hemant K Chitale



At 07:57 AM Monday, John Smith wrote:
I am studying for the OCP, and one of the practice test questions is how to recover from a lost active online redo log in noarchivelog mode.  the answer they give is to restore a consistent backup, startup in mount mode, perform a cancel based recovery, and open with resetlogs.

Is that answer correct?  I didnt think you could do a recovery if you arent in archivelog mode.


Hemant K Chitale
http://hemantoracledba.blogspot.com

"A 'No' uttered from the deepest conviction is better than a 'Yes' merely uttered to please, or worse, to avoid trouble."
Mohandas Gandhi Quotes :  http://www.brainyquote.com/quotes/authors/m/mohandas_gandhi.html


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