During the simulation, you created a recovery catalog. The correct steps for creating the catalog are as follows:

1. Log into SQL*Plus, create a user ‘rman’, and assign RECOVERY_CATALOG_OWNER to this user.
2. Log into RMAN by using the user created into ‘greatpets’ database.
3. To create the recovery catalog, issue the CREATE CATALOG command.

RMAN can be used with or without a recovery catalog.
A recovery catalog is a schema stored in a database that tracks backups and stores scripts for use during the RMAN backup and recovery situations.
An experienced DBA would suggest that the Enterprise Manager instance schema and RMAN catalog schema be placed in the same utility database on a server separate from the main servers. The RMAN schema generally only requires 16 megabyte per year for each database backed up.