RE: decision to use or not use an rman catalog?

I'd use rman w/o catalog unless you can come with a compelling reason
not to.  Reasons to use rman w/ catalog would be if you wanted to store
rman scripts in the catalog database, or if you were concerned with
keeping more history than can be kept in your controlfile.  Turn on the
controlfile autobackup option.
 
Regards,
Brandon

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