A>RMAN-05021: this configuration cannot be changed for a BACKUP or STANDBY control file
Cause: The user attempted to modify the
configuration which cannot be changed for a BACKUP or STANDBY control file
while the mounted control file was either BACKUP or STANDBY. The following
configurations can be changed only when connected to primary database instance
that has CURRENT/CREATED control file type mounted: CONFIGURE RETENTION [...]





