which situations may be used to perform restore operati…

Which three types of backups taken in which situations may be used to perform restore operations to a logical
standby database in a Data Guard environment?

A.
backups of data files taken on the primary database if connected to the recovery catalog where the logical
standby database is registered

B.
backups of data files taken on the standby database if connected to the recovery catalog where the logical
standby database is registered

C.
backups of control files taken on the primary database if connected to the recovery catalog where the
logical standby database is registered

D.
backups of data files taken on the logical standby database, if not connected to a recovery catalog

E.
backups of control files taken on the logical standby database if not connected to a recovery catalog

Explanation:
An RMAN recovery catalog is required so that backups taken on one database server can be restored to
another database server. It is not sufficient to use only the control file as the RMAN repository because the
primary database will have no knowledge of backups taken on the standby database.
Note: RMAN uses a recovery catalog to track filenames for all database files in a Data Guard environment. A
recovery catalog is a database schema used by RMAN to store metadata about one or more Oracle
databases. The catalog also records where the online redo logs, standby redo logs, tempfiles, archived redo
logs, backup sets, and image copies are created.
https://docs.oracle.com/database/121/SBYDB/rman.htm#SBYDB4853