Re: recovery by RMAN for a valid database?

From: David Fitzjarrell <oratune_at_aol.com>
Date: Fri, 17 Nov 2000 19:49:48 GMT
Message-ID: <8v424p$2fd$1@nnrp1.deja.com>

In article <8v400u$d6$1_at_nnrp1.deja.com>,   susana73_at_hotmail.com wrote:
> Hello,
>
> I am doing hotbackup using RMAN. My database isn't crashed and I
 didn't
> lose any datafiles. But one of the developers like to recover the
 data
> back to a certain point of time(say Wednesday 12pm, 2 days ago).
 Anyone
> knows how to do that on RMAN?
>
> Thanks in advance,
>
> Susan
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

Assume the following situation:

You run RMAN with a recovery catalog.

You made a backup of PROD1 on July 2, 1999.

You performed incomplete recovery on this database and opened it with the RESETLOGS option on July 10, 1999. A new database incarnation was created.

On July 25, you discover that you need crucial data that was dropped from the database at 8:00 a.m. on July 8, 1999. You decide to reset PROD1 to the prior incarnation, restore the July 2 backup, and then recover to 7:55 a.m. on July 8.

---

Note:
It is not possible to restore one datafile of a previous incarnation while the current database is in a different incarnation--you must restore the whole database.

---

To recover the database using the backup from the old incarnation:

You obtain the primary key of the previous incarnation by executing a list command:

# obtain primary key of old incarnation
list incarnation of database prod1;

List of Database Incarnations

DB Key  Inc Key   DB Name   DB ID       CUR    Reset SCN    Reset Time
------- -------   -------   ------      ---    ----------   ----------
1       2         PROD1     1224038686  NO     1            02-JUL-99
1       582       PROD1     1224038686  YES    59727        10-JUL-99

You reset the incarnation using the primary key that you just obtained:

# reset database to old incarnation
reset database to incarnation 2;

You recover the database, performing the following operations in the run command:

Set the end time for recovery to the time just before the loss of the data.

Allocate one or more channels.

Abort the instance and then re-start it.

Restore the control file and mount it.

Restore and recover the database.

Reset the online redo logs.

run {

     set until time 'Jul 8 1999 07:55:00'; # set time to just before data was lost

     allocate channel dev1 type disk;
     shutdown abort;
     startup nomount;
     restore controlfile;
     alter database mount; # mount database after restoring control file
     restore database;
     recover database;
     alter database open resetlogs; # this command automatically resets
the database
                                    # so that this incarnation is the

new incarnation
}

I hope this helps.

--
David Fitzjarrell
Oracle Certified DBA


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Before you buy.

Received on Fri Nov 17 2000 - 13:49:48 CST