Re: Recovering rollback tablespace

Hi Sam,

See comments inline...

Sam Jordan wrote:

> Hi
>
> I am right now playing with a lot of disaster scenarios (backup/
> recovery) to be prepared for a real-world disaster...
>
> I stumbled over problems after I deleted the datafile associated
> to the rollback segment tablespace (while Oracle was running). First
> I wanted to do some stuff in sqlplus to make an error message appear,
> and this worked. Afterwards I tried to fix this error and to make
> the database working again.
>
> The first problem was, that I was unable to put the rollback
> tablespace offline (I typed the appropriate command into svrmgrl,

Did you try OFFLINE IMMEDIATE, OFFLINE will want to checkpoint the data file, which if you have destroyed is not possible, OFFLINE IMMEDIATE does just this, don't try to checkpoint the tablespace. Also, I think you are running into additional problems since the ROLLBACK segments were in the tablespace. This on it's own I would have thought would bring down the database, unless you got the rollback segments offline somehow.

>
> but it only hanged). Is this normal? Actually for a lot of
> recovery operations the tablespace should be put into
> offline state, at least I have read that.

Agreed that the tablespace, or datafiles, should be taken offline for recovery.

>
>
> Second problem: I couldn't shutdown Oracle with immediate parameter,
> it simply refused to shut down due to missing datafiles. I did
> a shutdown abort next time, restored the missing datafile and
> restarted Oracle, followed by a recovery operation on the rollback
> datafile. Actually it worked, but I am not happy at all about the
> fact that I had to 'shutdown abort' the database, which would also
> mean, that I should better do a full database recovery instead of
> restoring only the rollback tablespace/datafile. Again, is this
> normal?

Shutdown IMMEDIATE will mean that all transactions that are currently active should be rolled back, but haven't we just lost the rollback segments, so how can we perform the rollback. Therefore, Shutdown ABORT is required.

>
>
> Has anyone had a similar case (missing rollback tablespace/datafile)
> and can report of its own experiences?

I've done a number of disaster recovery scenarios now, and missing datafiles, logfiles are included in this. No problems to report todate.

>
>
> bye
> --
> Sam Jordan

Rgds
Andrew Received on Wed May 05 1999 - 19:39:47 CDT