单项选择题 You want to use the automatic management of backup and recovery operations features for your database.Which configuration must you set?（）

多项选择题 Examine the following command used to perform incremental level 0 backup: RMAN> BACKUP INCREMENTAL LEVEL 0 DATABASE; To enable the block change tracking, after the incremental level 0 backup you issued the following command: SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE /mydir/ rman_change_track.f; To perform incremental level 1 cumulative backup, you issued the following command: RMAN> BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE; Which two statements are true in the above situation?（）

单项选择题 To accomplish user-managed backup for the USERS tablespace, you issued the following command to put the database in backup mode: SQL> ALTER TABLESPACE users BEGIN BACKUP; While copying the file to the backup destination a power outage caused the instance to terminate abnormally. Which statement is true about the next database startup and the USERS tablespace?（）