Re: RMAN - Rewind Backup to SCN/Point-in-Time
Date: Wed, 28 Sep 2011 11:39:38 -0700 (PDT)
Can you show us the exact commands you are using and the output for the duplicate you are doing (both the backup AND the subsequent duplication). Without that, I'm just speculating, though I think I know the answer to why you see it working as you do. Also is the backup done online or offline (database up or down, open or closed, however you call it) :) A backup taken offline has some subtle differences that can make it recoverable without redo logs that a online backup does not have. I assure you. If your only backup ended at SCN 2000, you can NOT restore the database to SCN 1999 unless you are going to be doing some flashback work. Just does not work that way. Period. End of statement. Booyahhhh. :)
Robert G. Freeman
Master Principal Consultant, Oracle Corporation, Oracle ACE Author of various books on RMAN, New Features and this shorter signature line. Blog: http://robertgfreeman.blogspot.com
Note: THIS EMAIL IS NOT AN OFFICIAL ORACLE SUPPORT COMMUNICATION. It is just the opinion of one Oracle employee. I can be wrong, have been wrong in the past and will be wrong in the future. If your problem is a critical production problem, you should always contact Oracle support for assistance. Statements in this email in no way represent Oracle Corporation or any subsidiaries and reflect only the opinion of the author of this email.
From: Alan Sterger <asterger_at_earthlink.net> To: oracle-l_at_freelists.org
Sent: Wednesday, September 28, 2011 10:34 AM Subject: Re: RMAN - Rewind Backup to SCN/Point-in-Time
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?
- 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?
> -- 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?
>> -- 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 220.127.116.11 and in Archivelog mode.
>>> -- Alan Sterger