单项选择题
A. You must have change tracking enabled in your database
B. Your database must be running in NOARCHIVELOG mode
C. To back up a tablespace，it must be in backup mode
D. To back up a tablespace，it must first be taken offline
单项选择题 Examine the following RMAN script: RMAN> run { debug on; allocate channel c1 type disk; backup datafile 5; } Which statement describes the purpose of the script?（）
单项选择题 What does the DB_FLASHBACK_RETENTION_TARGET parameter configure?（）
多项选择题 IdentifytheactivitiesperformedaspartoftheAutomaticSQLTuningprocessinthemaintenancewindow？（）