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RE: Restoring control file required?

From: Ted Coyle <oracle-l_at_webthere.com>
Date: Fri, 3 Aug 2007 10:05:03 -0400
Message-ID: <000601c7d5d7$4a1d7d40$3921a8c0@medecision.com>


Nadeem,
There are both simple and complicated reasons requiring older control file versions.

The "database dropping" issue sounds like you are more familiar with SQL Server or other like databases since there is no "Drop Database" that is relevant in Oracle.

Of course, if you rm -r directories containing redo, control or other datafiles, you have essentially "dropped".

I've used control file restores for point-in-time pseudo-recovery for database replication.

As example, I have a backup that I want to restore; I have the latest control file. An unrecoverable action occurs such as direct path load, or adding a datafile. I don't want to mess with the point-in-time issues, so rather than use the latest control file, I'll restore the one from right after the backup and use this one to restore a database copy.

In your case, you are asking how to recover a dropped tablespace and yes, the easiest way, in my opinion is to restore the control file and datafiles from the last full backup and roll forward to the point in time just prior to the tablespace drop.

There are also more advanced ways to do this such as Tablespace Point in Time Recovery, but they need previous preparation and knowledge to succeed. Here's some docs on this:
http://download.oracle.com/docs/cd/B19306_01/backup.102/b14191/rcmtspit002.h tm#i1013426

Ted

-----Original Message-----

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Nadeem M. Khan
Sent: Friday, August 03, 2007 2:33 AM
To: oracle-l_at_freelists.org
Subject: Restoring control file required?

Greetings.

Got a teeny weeny doubt here.
When is it necessary to restore the controlfile? Ofcourse one scenario is when I have lost all copies of my current control file.

Suppose I lose a datafile, I need to restore it. But do I need to restore the control file as well for recovering? What if a tablespace is dropped?

My conclusion after doing a bit of R&D is that if a datafile is dropped/damaged, the
controlfile need not be restored. But If a tablespace is dropped then then all datafiles and the controlfile need to be restored for (incomplete) recovery.

Any inputs appreciated. Documents/Links even more appreciated.

Regards,
NMK.
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http://www.freelists.org/webpage/oracle-l Received on Fri Aug 03 2007 - 09:05:03 CDT

Original text of this message

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