The most important - do not panic.
Than, read note 94119.1 on MetaLink.
Here is a part of it:
Recovery with missing online redo logs
Missing online redo logs means that somehow you have lost your redo logs before they
had a chance to archived. This means that crash recovery cannot be performed, so
media recovery is required instead. All datafiles will need to berestored and rolled
forwarded until the last available archived log file is applied. This is thus an
incomplete recovery, and as such, the recover database command is necessary. (i.e.
you cannot do a datafile or tablespace recovery). As always, when an incomplete
recovery is performed, you must open the database with resetlogs. Note: the best way
to avoid this kind of a loss, is to mirror your online log files.
Recovery with missing archived redo logs
If your archives are missing, the only way to recover the database is to restore
from your latest backup. You will have lost any uncommitted transactions which were
recorded in the archived redo logs. Again, this is why Oracle strongly suggests
mirroring your online redo logs and duplicating copies of the archives.
Recovery with resetlogs option
Reset log option should be the last resort, however, as we have seen from above, it
may be required due to incomplete recoveries. (recover using a backup control file,
or a point in time recovery). It is imperative that you backup up the database
immediately after you have opened the database with reset logs. The reason is that
oracle updates the control file and resets log numbers, and you will not be able to
recover from the old logs. The next concern will be if the database crashes after
you have opened the database with resetlogs, but have not had time to backup the
database.
How to recover?
Shut down the database
Backup all the datafiles and the control file
Startup mount
Alter database open resetlogs
This will work, because you have a copy of a control file after the esetlogs
point.
Media failure before a backup after resetlogs.
If a media failure should occur before a backup was made after you opened the
database using resetlogs, you will most likely lose data. The reason is because
restoring a lost datafile from a backup prior to the resetlogs will give an error
that the file is from a point in time earlier, and you don't have its backup log
anymore.
Good luck.
inka
-----Original Message-----
Sent: Wednesday, September 18, 2002 4:44 PM
To: Multiple recipients of list ORACLE-L
What about mirrored redo group members?
Igor Neyman, OCP DBA
[EMAIL PROTECTED]
----- Original Message -----
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Wednesday, September 18, 2002 4:30 PM
Hi people...
What to do if I have LOST ALL REDO LOGS and i donīt have any backup?
Thanks in advance!
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Gilberto Gampert Universidade de Passo Fundo
Administrador de Banco de Dados Passo Fundo - RS - Bra5il
[EMAIL PROTECTED] http://www.upf.br
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
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