Re: reinstate database without flashback/DB Restore/RMAN
Date: Thu, 4 Jun 2015 16:30:39 -0500
Message-ID: <CAKoJ+qA4n+CNcx3+1OdbrX+TCPazYsgYW+i1fjcpQ4NmA3B2HA_at_mail.gmail.com>
okay now it make sense. I was under the impression that failover does NOT resetlogs and i was wrong. Thank you for that clarification.
Also special thanks to you for helping me out this week and of course the entire list.
On Thu, Jun 4, 2015 at 4:25 PM, Andrew Kerber <andrew.kerber_at_gmail.com> wrote:
> When you fail over you have to open resetlogs. Switchover is a clean
> switch, no resetlogs required.
>
> On Thu, Jun 4, 2015 at 4:23 PM, max scalf <oracle.blog3_at_gmail.com> wrote:
>
>> okay make sense, one question when we FAILOVER why does the DBID changes
>> ?? or is it also doing a resetlogs ?
>>
>> On Thu, Jun 4, 2015 at 3:16 PM, Andrew Kerber <andrew.kerber_at_gmail.com>
>> wrote:
>>
>>> I am referring to the original primary in that case. As I understand
>>> it, with flashback turned on, the reinstate command in dgmgrl will flash
>>> the original primary back to an earlier point, then apply the logs from the
>>> current primary to put the original primary into standby mode, ready for a
>>> clean switchover.
>>>
>>> On Thu, Jun 4, 2015 at 2:57 PM, max scalf <oracle.blog3_at_gmail.com>
>>> wrote:
>>>
>>>> Thanks Andrew, i did not realized that. Also looks like the log seq#
>>>> resets back to 1 on the new primary(DC-B).
>>>>
>>>> Also when you mentioned "flashback allows you to flash the PRIMARY back
>>>> to an instance before the divergence and start the apply"...are you talking
>>>> in this situation the CURRENT PRIMARY (DC-B) which has been up for 4 hours
>>>> now will be flashed back to noon followed by rollforward ?? Wouldnt that
>>>> be on the standby ??
>>>>
>>>> On Thu, Jun 4, 2015 at 2:40 PM, Andrew Kerber <andrew.kerber_at_gmail.com>
>>>> wrote:
>>>>
>>>>> 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.'
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Andrew W. Kerber
>>>
>>> 'If at first you dont succeed, dont take up skydiving.'
>>>
>>
>>
>
>
> --
> Andrew W. Kerber
>
> 'If at first you dont succeed, dont take up skydiving.'
>
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Jun 04 2015 - 23:30:39 CEST