Your database is running in ARCHIVELOG mode, and the database is open. You execute
an RMAN backup and specify the KEEP clause.
Which components are backed up when this option is specified?
A.
only the control file, the current SPFILE, and data files
B.
only the current SPFILE and data files if autobackup is disabled
C.
only the data files and the archived redo logs
D.
the control file, current SPFILE file, data files, and archived redo logs
KEEP clause:
Specifies the backup as an archival backup, which is a self-contained backup that is exempt from the configured retention policy.
An archival backup is self-contained because is contains all files necessary to restore the backup and recover it to a consistent state. If the database is open during the backup, then RMAN automatically generates and backs up the archived redo logs needed to make the database backup consistent
http://docs.oracle.com/cd/B28359_01/backup.111/b28273/rcmsubcl011.htm#RCMRF131