RE: RMAN - Rewind Backup to SCN/Point-in-Time

When specifying a scn number (or sequence number or time) with the until clause, you tell Oracle that you want to restore up to that point.

Oracle will then look for a backup created before that point and then use the archivelogs to roll forward from the time of the backup to that point.

If the archivelogs required to do this are not available on disk, Oracle will try to restore them from backup and then apply them.

In your original post, you spoke about recovering to a point before the last level 0 backup. If you have backups created before the point you want to restore to, you only need to specify the until clause and Oracle will automatically select the last level 0 backup created before that point and start applying later incremental backups and archivelogs until it the recovery has reached your specified restore point.

If you don't have any backups, the earliest point up to which you need to restore, is the end time of the earliest level 0 backup. Maybe that you can flashback some tables as the information required to do so is stored in the undo tablespace, but I'm not sure about this (as an incomplete recovery will issue a new incarnation point).

Regards,  

Freek D'Hooge
Uptime
Oracle Database Administrator
email: freek.dhooge_at_uptime.be
tel +32(0)3 451 23 82
http://www.uptime.be
disclaimer: www.uptime.be/disclaimer

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Alan Sterger Sent: woensdag 28 september 2011 19:35
To: oracle-l_at_freelists.org
Subject: Re: RMAN - Rewind Backup to SCN/Point-in-Time

Hello List,

Let's take a slightly different tack: I use RMAN Duplication to create test databases. Backups execute at 5AM, I create the clone at 9PM. I copy just the RMAN backup pieces to the Aux server, no archivelogs. On RMAN's first pass, receive:
RMAN-06053: unable to perform media recovery because of missing log RMAN-06025: no backup of log thread 1 seq nnnn scn nnnnnnnnn found to restore.

For the next pass, add UNTIL SCN clause of nnnnnnnnn-1 and the duplication succeeds. This led me to think if SCN can be manipulated for duplication, why can't it be manipulated for restore?

Your thoughts?

Cheers,

• Alan Sterger

On 9/27/2011 10:53 PM, Alan Sterger wrote:
> Hello List,
>
> I've been a DBA since Oracle 7 on enterprise class systems. Back
> then, there was no RMAN. Most backups where done cold, using Backup
> Exec, Veritas, ... Even when RMAN was released, most enterprises were
> happy with their big iron tape robots or had advanced to hot, split
> mirror backups. So yes, my knowledge of RMAN is stunted.
>
> Robert I did buy your 10g RMAN book and have read it. I was hoping
> for more recovery scenarios but alas, a book can't be all things to
> all people.
>
> Yes, I want to recover to an earlier SCN or point-in-time than is
> contained within an incremental level 0 backup. The point is to
> recover, the tool or method is not important. How about SQLPlus? How
> about Log Miner?
>
> Cheers,
>
> -- Alan Sterger
>
> On 9/27/2011 9:12 PM, Alan Sterger wrote:
>> Hello List,
>>
>> To add more information:
>>
>> Client once asked to restore the whole database to sometime the day
>> before the last full RMAN incremental level 0 backup. All datafiles,
>> control files and redo were on-line. The level 0 backup was
>> successful with 'archivelog all delete input', so there are no
>> archivelogs to rewind.
>>
>> Its all in the RMAN backup.
>>
>> I was thinking incomplete recovery to SCN or point-in-time with
>> RESETLOGS might do it. I'm building a test database to try various
>> recovery scenarios.
>>
>> To reiterate: Can an entire database be recovered to an SCN or
>> point-in_time using UNTIL SCN or UNTIL TIME clause from just an
>> incremental level 0 backup?
>>
>> Cheers,
>>
>> -- Alan Sterger
>>
>> On 9/27/2011 3:18 PM, Alan Sterger wrote:
>>> Hello List,
>>>
>>> Is it possible to take an RMAN backup (full or incremental level 0)
>>> and rewind it, rollback to a SCN or point-in-time within the
>>> controlfile's CONTROL_FILE_RECORD_KEEP_TIME window?
>>>
>>> Database is 9.2.0.8 and in Archivelog mode.
>>>
>>> Cheers,
>>>
>>> -- Alan Sterger
>>>
>>>

--
http://www.freelists.org/webpage/oracle-l


--
http://www.freelists.org/webpage/oracle-l