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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Lost ofall redo logs
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
ineyman_at_perceptron.com
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 gampert@upf.br http://www.upf.br :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
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Author: Gilberto Gampert
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Author: Igor Neyman
INET: ineyman_at_perceptron.com
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting servicesto: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
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Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting servicesto: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Wed Sep 18 2002 - 16:03:24 CDT
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