Explanation/Reference:
Explanation:
Overview of Block Media Recovery (link)
Basic Concepts of Block Media Recovery
Whenever block corruption has been automatically detected, you can perform block media recovery manually with the RECOVER ... BLOCK command. By default, RMAN first searches for good blocks in the real-time query physical standby database, then flashback logs and then blocks in full or level 0 incremental backups.
Prerequisites for Block Media Recovery (link)
The following prerequisites apply to the RECOVER ... BLOCK command:
The target database must run in ARCHIVELOG mode and be open or mounted with a current control

file.
If the target database is a standby database, then it must be in a consistent state, recovery cannot be in

session, and the backup must be older than the corrupted file.
The backups of the data files containing the corrupt blocks must be full or level 0 backups and not

proxy copies.
If only proxy copy backups exist, then you can restore them to a nondefault location on disk, in which case RMAN considers them data file copies and searches them for blocks during block media recovery.
RMAN cannot use level 1 incremental backups. Block media recovery cannot survive a missing or inaccessible archived redo log, although it can sometimes survive missing redo records.
Flashback Database must be enabled on the target database for RMAN to search the flashback logs for good copies of corrupt blocks. If flashback logging is enabled and contains older, uncorrupted versions of the corrupt blocks, then RMAN can use these blocks, possibly speeding up the recovery. The target database must be associated with a real-time query physical standby database for RMAN to search the database for good copies of corrupt blocks.
Restore Failover (link)
RMAN automatically uses restore failover to skip corrupted or inaccessible backups and look for usable backups. When a backup is not found, or contains corrupt data, RMAN automatically looks for another backup from which to restore the desired files.