Re: Recovery question

On Thu, 01 Jun 2000 00:12:29 GMT, Big Al <db-guru_at_att.net> wrote:

Al,

Thanks for the great info!

Michael

>Michael Atkins wrote:
>>
>> Hi,
>>
>> Running 7.3.3 in an NT enviroment. Recovering from a power outage.
>> My system tablespace is in need of media recovery. I run in
>> NOARCHIVELOG mode and my redo logs sequence numbers are higher than
>> what I need. Any ideas how else I can recover this? I've heard that
>> there is a way to disable the sequence problem and login with invalid
>> redo logs, but that doesn't sound like a good idea.
>>
>> TIA,
>> Michael
>
>Running in NOARCHIVELOG mode doesn't give you many options. I hope you
>have a current backup. All you can do is restore all your files to the
>last offline backup. Then the SCN numbers should be in synch across the
>datafiles and allow you to start your system. If you don't back up your
>redo logs at the same time as your datafiles, you can restore all the
>datafiles, open the database in mount mode and then enter ALTER DATABASE
>OPEN RESETLOGS; This is a powerful command and needs to be used with
>caution. Be careful. Additional info from a recovery guide I wrote:
>
>Reset Database
>
>When necessary, this is part of the OPEN database command after the
>recovery process has completed. It should never be used except when
>absolutely necessary because you cannot recover over a RESETLOG. The
>three cases where it is necessary to use this are:
>1) An incomplete recovery has been performed because of lost online
>redo logs or a missing archived redo log.
>2) Recovery was performed with a backup control file.
>3) Recovery was performed with a control file that was created by the
>CREATE CONTROLFILE command with the RESETLOGS option.
>The DBA is responsible for ensuring that all the Oracle files are
>consistent before entering this command. With the database reset Oracle
>sets the System Change Numbers (SCN) in each file to a new checkpoint
>without checking the the state of the files. Any offline data files may
>not be reset so they will have to be dropped as they cannot be recovered
>after this command. The command is: ALTER DATABASE OPEN RESETLOGS;
>
>After using this command it is essential to immediately take either an
>online or offline backup. I recommend doing an immediate shutdown of
>Oracle and an offline backup because you have no recovery available if
>there is an Oracle failure during the online backup.
>
>
>Big Al
Received on Thu Jun 01 2000 - 00:00:00 CDT