Re: reinstate database without flashback/DB Restore/RMAN

From: Ram Cheruvattath <ram.cheruvattath_at_gmail.com>
Date: Fri, 5 Jun 2015 08:08:53 -0400
Message-ID: <F9FAEE9669C942228496E2E220968690_at_RAMPC>



The DBID on a physical standby should not change due to a failover. Have you tested this?

Ram

From: Andrew Kerber
Sent: Thursday, June 04, 2015 3:40 PM
To: max scalf
Cc: Oracle Mailing List
Subject: Re: reinstate database without flashback/DB Restore/RMAN

Nope. At that point, if you have a done failover, the dbid on the standby is different from the primary. In effect, at that point its a completely different database. Flashback allows you to flash the primary back to an instant before the divergence, and you can apply the logs from that point, but you have to flash it back for that to work.

On Thu, Jun 4, 2015 at 1:29 PM, max scalf <oracle.blog3_at_gmail.com> wrote:

  Hello list,

  I am trying to get my head around reinstating a database in dataguard scenario, i am very new to DG and hence having issue trying to understand this.

  So lets say i have datacenter DC-A and Datacenter DC-B and i have setup DG between the two(Max Perf mode). Now lets say DC-A goes down unexpectedly (and lets assume that DC-A will come back up in 3-4 hours as know we know whats wrong and network team is trying to fix that), also lets assume this happened at noon and my log seq# at primary was 300. Obviously in the mean time i am going to FAILOVER to standby in DC-B and everything is happy. Time passes along and now its 4PM and lets assume now my primary in DC-B is at log seq# 320.

  Now at 4PM, my DC-A is back and i want to bring the former primary into standby mode. I can either use flashback(if enabled earlier) or recreate my standby again to do that. My question is, instead of using flashback or rman to recreate my standby(DC-A), cant i just mount my database in DC-A, copy over logs from seq# 300-320 from DC-B on to DC-A, roll forward DC-A and then start my redo apply instead of recreating standby(or using flashback)??

  I guess in short i am asking y do we have to use flashback or use RMAN/re-create to reinstate my standby database? is there any other way to reinstate my database(fromer primary).

-- 

Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

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Received on Fri Jun 05 2015 - 14:08:53 CEST

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