单项选择题
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.
单项选择题 The BACKUP_TAPE_IO_SLAVES parameter is set to FALSE for the database instance. Which statement istrue while performing a tape backup in an RMAN session?（）
单项选择题 Examine the following ALTER command: SQL> ALTER DISKGROUP dgroup1 UNDROP DISKS; What is the purpose of the command?（）
多项选择题 WhichtasksarerunautomaticallyaspartoftheAutomatedMaintenanceTaskbydefault？（）