Which three are true about using RMAN in a Data Guard environment?

In a Data Guard configuration with a physical standby, the data files are block-for-block identical to the primary. Therefore, RMAN backups of data files taken on the physical standby can be used to restore the primary database (D). Similarly, the archived redo logs are identical, and their backups are interchangeable (A). However, the control file of a physical standby is different from the primary's (it is created with the FOR STANDBY clause), so its backups are not interchangeable and cannot be used to restore the primary control file (B).

C. A recovery catalog is recommended but not required. RMAN can register backups taken on a standby in the primary's control file, allowing for recovery without a catalog.
E. Backups from a logical standby cannot be used to restore the primary. A logical standby is a separate, reorganized database and is not a physical copy.

1. Oracle Backup and Recovery User's Guide, 19c, E96519-12, Chapter 26, "Using RMAN in a Data Guard Environment".

2. Oracle Backup and Recovery User's Guide, 19c, E96519-12, Section 26.1.2, "Interchangeability of Backups in a Data Guard Environment". "Backups of data files and archived redo log files created on one database are accessible to and can be restored on the other database."

3. Oracle Backup and Recovery User's Guide, 19c, E96519-12, Section 26.1.2, "Interchangeability of Backups in a Data Guard Environment". "Backups of the control file and standby control file are not interchangeable."

4. Oracle Backup and Recovery User's Guide, 19c, E96519-12, Section 26.2, "Configuring RMAN in a Data Guard Environment". "A recovery catalog is strongly recommended... However, a recovery catalog is not required."