You backed up the database at 8 a.m. today using an online backup. Accounting made a large change to the underlying data between 10 a.m. and noon. 
Which of the following actions would ensure that the changes could be recovered using the 8 a.m. backup？（）  

单项选择题YouwanttoputaspecifictablespacecalledMY_DATAinhotbackupmodesoyoucanbackitup.Whatcommandwouldyouuse？（）

A. alter tablespace MY_DATA begin backup
B. alter tablespace MY_DATA start backup
C. alter tablespace MY_DATA backup begin
D. alter MY_DATA begin backup
E. You cannot back up individual tablespaces

单项选择题When performing an online backup，what is the proper order of the following steps？（）   a. Issue the alter database end backup command. b. Back up the archived redo logs. c. Issue the alter database begin backup command.  d. Back up the database files.  e. Determine the beginning log sequence number. f. Determine the ending log sequence number.  g. Force a log switch with the alter system switch logfile command.

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

单项选择题YourdatabaseisinNOARCHIVELOGmode.Youstarttodoabackup，butyouruserscomplainthattheydontwantyoutoshutdownthedatabasetoperformthebackup.Whatoptionsareavailabletoyou？（）

A. Put the database in hot backup mode and perform an online backup，including backing up the  archived redo logs.
B. Just back up the database datafiles without shutting down the database.
C. You will have to wait until you can shut down the database to perform the backup.
D. Mark each datafile as backup in progress， back them up individually，and then mark them as backup not in progress. No archived redo logs will need to be backed up.
E. Only back up the datafiles that the user will not be touching. Once the user has finished what they were doing，you can shut down the database and back up the datafiles the user changed during the  course of the remaining backup

多项选择题As the DBA， you run the following query on your ASM instance. What is the implication of the results of the query？（） SQL> select group_number， name， state from v$ASM_DISKGROUP；  GROUP_NUMBER NAME STATE  0 DGROUP1 DISMOUNTED  2 DGROUP2 MOUNTED  3 DGROUP3 MOUNTED

A. The DGROUP1 disk group was unmounted by another DBA.
B. A datafile has been lost， causing the ASM disk group DGROUP1 to go into the DISMOUNTED state
C. One of the redundant disks （DGROUP1） has been lost in a disk group.
D. This query has no meaning in an ASM instance.
E. A disk associated with a disk group was discovered after the ASM instance initially opened.

单项选择题You are an Oracle DBA responsible for an ASM instance. The disk controller on your system fails. You suspect that the disk itself is okay. You know it will take 24 hours to replace the controller and you don’t want to have to rebuild the disks from scratch.  What do you do？（）

A. Take the whole disk group offline and wait for the controller card to be installed. Once it’s installed，bring the disk group online again.
B. Change the ASM parameter ASM_PREFERRED_READ_FAILURE_GROUPS to indicate that you want to read from the non-failed disk. Once the disk controller is replaced，reset the parameter to  its original value.
C. You have no choice but to rebuild the disk. Drop the disk from the disk group and wait for the controller to be replaced. Once the controller is replaced， add the disk back into the disk group and allow ASM to rebuild it.
D. If you are using any setting other than REDUNDANCY EXTERNAL for your disk group，you will have to recover any data on that disk from a backup. The database will be unavailable until you can  correct the problem and perform recovery.
E. Change the attribute DISK_REPAIR_TIME on the disk group to a time greater than 24 hours.