Which command would you use to determine what database backups are currently available for restore？（）  

单项选择题David managed to accidentally delete the datafiles for database called DSL. He called Heber and Heber tried to help but he managed to delete the control files of the database. Heber called Bill and Bill saved the day. They are using a recovery catalog for this database.  What steps did Bill perform to recover the database and in what order？（）   a. Restored the control file with the RMAN restore controlfile command.  b. Mounted the DSL instance with the alter database mount command.  c. Restored the datafiles for the DSL database with the RMAN restore command. d. Opened the DSL database with the alter database open resetlogs command. e. Recovered the datafiles for the DSL database with the RMAN recover command. f. Started the DSL instance.  g. Connected to the recovery catalog with RMAN.

A.  a， b， c， d， e， f， g
B. b， c， d， g， f， e， a
C. g， f， a， b， c， e， d
D. c， a， d， b， f， e， g
E. g， f， a， b， e， c， d

单项选择题Whichofthefollowingrepresentsthecorrectwaytoperformanonlinerecoveryofdatafile4，whichisassignedtoatablespacecalledUSERS？（）

A. shutdown restore datafile 4； recover datafile 4； alter database open；
B. Sql alter database datafile 4 offline； restore datafile 4； recover datafile 4； alter database open；
C. Sql alter database datafile 4 offline； restore datafile 4； Sql alter database datafile 4 online；
D. Sql alter database datafile 4 offline； restore database datafile 4； recover database datafile 4；Sql alter database datafile 4 online；
E. Sql alter database datafile 4 offline； restore datafile 4； recover datafile 4； Sql alter database datafile 4 online；

单项选择题What will be the end result of this set of RMAN commands？（）   shutdown abort startup mount  restore datafile 4 until time ，，09 30 2008：15：00：00；  recover datafile 4 until time ，，09 29 2008：15：00：00；  alter database open resetlogs；

A. Datafile 4 will be recovered until 9/30/2008 at 15：00 and the database will open.
B. The restore command will fail.
C. The recover command will fail.
D. The alter database open resetlogs command will fail.
E. All these commands will fail because they must be in the confines of a run block.

单项选择题IfyoufinderrorsintheviewV$DATABASE_BLOCK_CORRUPTIONwithastatusofMEDIA_CORRUPT，whatRMANcommandwouldyouruntocorrecttheproblem？（）

A. recover lost blocks
B. recover corrupt blocks
C. recover media corrupt blocks from list
D. recover corrupt blocks from list
E. recover corruption list

多项选择题You have a database with the following tablespaces： SYSTEM， SYSAUX， UNDO， USERS， TEMP. You want to roll back  the data in the USERS tablespace to the way it looked yesterday.  Which tablespaces do you need to perform a point-in-time restore operation on in order to complete this task？（）

A. SYSTEM
B. SYSAUX
C. UNDO
D. USERS
E. TEMP
F. This restore is not possible