单项选择题 Examine the following scenario: The target database instance is running. The most recent backup available for the target database was taken two days ago. Log files switches have occurred in last two days. The target database is duplicated on the same host, using the Recovery Manager (RMAN) duplicate command as follows: Which statement is true about the duplicate database in this scenario?（）

单项选择题 TheDatabaseResourceManagerisautomaticallyenabledinthemaintenancewindowthatrunstheAutomatedMaintenanceTask.Whatisthereasonforthis？（）

单项选择题 You executed the following commands：   SQL> ALTER SESSION SET OPTIMIZER_USE_PENDING_STATISTICS = false； SQL> EXECUTE DBMS_STATS.SET_TABLE_PREFS（’SH’， ’CUSTOMERS’， ’PUBLISH’，’false’）； SQL> EXECUTE DBMS_STATS.GATHER_TABLE_STATS（’SH’， ’CUSTOMERS’）；   Which statement is correct regarding the above statistics collection on the SH.CUSTOMERS table in the above session？（）