Multiplexing redo logs has nothing to do with the archive mode. Logs are multiplexed so that an error writing to one of the members in a group does not cause the instance to terminate.

Myth - If you use disk mirroring, you don't need to multiplex your redo logs.
Reality - Mirroring only protects from hardware failure. It will not protect you from accidental deletion of the log (been there, had to fix it!).
-- 
Daniel W. Fink
http://www.optimaldba.com

IOUG-A Live! April 27 - May 1, 2003 Orlando, FL
   Sunday, April 27 8:30am - 4:30pm - Problem Solving with Oracle 9i SQL
   Thursday, May 1 1:00pm - 2:00pm - Automatic Undo Internals

GovindanK wrote:
Shutdown abort is pretty drastic, are you sure shutdown immediate didn't 
work?
    

Well said. This topic has been circulating in many DBA forums for a long time. Shutdown immediate does rollback and will take time if no.of users
is high. On the otherside, shutdown abort simply takes the db down and 
does not bother about anything else. As per manual, if you do a shutdown abort then you WILL need the online redo logs for recovery just in case.
Think twice if your db is in NOARCHIVELOG mode. If your db is in ARCHIVE mode make sure the logs are multiplexed.  Though Oracle's recovery seems
to be sturdy, double check your backup & recovery strategies. Also, which option to use is influenced by how much downtime/shutdown time you can afford.

HTH

GovindanK
  


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