Question: What is the difference
between the RMAN catalog and nocatalog mode? Should I
always use the nocatalog mode with a single database?
Answer: The RMAN catalog and nocatalog
arguments are used to indicate whether an operation is to be
stored in the RMAN catalog schema. The default for the
"rman" command is nocatalog.
The RMAN recovery catalog is a schema stored in a
database that tracks backups and stores scripts for use in
RMAN backup. For most all backup operations, you will want
to connect to both the database and the backup recovery
catalog, using the "catalog" option.
According to the
docs, the RMAN catalog command is used in these
circumstances:
- Add
metadata about a user-managed datafile, control file, or
archived log copy to the recovery catalog and control
file.
- Record a
datafile copy as a level 0 backup in the RMAN
repository, which enables you to use it as part of an
incremental backup strategy.
- Record
the existence of user-managed copies of Oracle release
8.0 or later databases created before RMAN was
installed.
- Record
the existence of the last user-managed datafile copies
made after the final shutdown in Oracle version 7 and
before running the migration utility.
Here are examples of the RMAN catalog command:
RMAN> CATALOG ARCHIVELOG 'u01/app/oracle/oradata/mysid/rman/bkup5534.arc'
RMAN> CATALOG
BACKUPPIECE 'u01/app/oracle/oradata/mysid/rman/bkup5534.bkp'
