单项选择题
A.a list of files that require a backup within three days
B.a list of files that have not been backed up for three days
C.a list of files that RMAN recommends be backed up only once in every three days， based on low volatility
D.a list of files for which a backup has already been performed and may need a backup after three days
多项选择题 WhenperformingabackupusingRecoveryManager（RMAN），whichfourtypesoffilescanbebackedupwiththeRMANBACKUPcommand？（）
多项选择题 Your database is functioning in NOARCHIVELOG mode. Your database contains 15 tablespaces. You want to use Recovery Manager （RMAN） to perform backups. Which two backups would you be able to perform when the database is being accessed by users？（）
多项选择题 View the Exhibit. You executed the following command to perform a backup of the USERS tablespace： RMAN> BACKUP TABLESPACE USERS Which three types of files are backed up？ （）