You issue the following RMAN command to set a retention policy on a database:   RMAN>CONFIGURE RETENTION POLICY TO REDUNDANCY 2;   What will be the outcome of issuing this command?()  
A: After two days,a backup will be marked obsolete
B: After two days,a backup will be deleted from the media
C: If the RMAN repository has records of two or more recent backups of a file,then older backups will be deleted from the media.
D: If the RMAN repository has records of two or more recent backups of a file then older backups will be marked obsolete.
出自:Oracle认证