A.a， b， e， cB.b， e， dC.a， b， d， cD.b， g， c， fE.a， b， d，……

多项选择题Whatmethodsareavailabletorecoverlostcontrolfiles？（）

A. Backup control file.
B. Emergency control file.
C. The create controlfile command.
D. The restore controlfile SQL*Plus command.
E. No backup is required. The database will re-create the control file when it is discovered to be lost.

单项选择题Yourdevelopershaveaskedyoutorestorethedevelopmentdatabase，whichisinNOARCHIVELOGmode，backtolastTuesdaythe20th.YourlastbackupisfromMondaythe19th.Whatdoyoudo？（）

A. Restore the 19ths backup， restore all archived redo logs， recover the database to the 20th，and open the database.
B. Tell them that their request cannot be met with the current backup strategy.
C. Restore the 19ths backup， apply the online redo logs，and open the database.
D. Switch the database into ARCHIVELOG mode，restore the 19th’s backup，restore all archived redo  logs，and recover the database to the 20th.
E. Use the recover database command to roll back the database from today to the 19th of the month.

单项选择题You have lost all your database control files. To recover them， you are going to use the results of the alter database backup controlfile to trace command. Your datafiles and your online redo logs are all intact.  Which of the following is true regarding your recovery？（）

A. You will need to open the database with the resetlogs command.
B. All you need to do is execute the trace file from SQL*Plus and it will perform the recovery for you.
C. You will use the resetlogs version of the create controlfile command.
D. You will use the noresetlogs version of the create controlfile command.
E. You will use the trace file to create a backup control file， and then you will recover the database with the recover database using backup controlfile command

单项选择题A user sends you an email with the following error message： create table idtable（id number） * ERROR at line  1： ORA- 01110： data file 4： ，， oracle01 oradata orcl users01.dbf ORA-27041： 01116： error in opening database file 4 ORA-unable to open file Linux Error：  2： No such file or directory Additional information：  3 You can choose from the following steps： a. Restore the missing database datafiles.  b. Take the missing datafile offline.  c. Shut down the database.  d. Issue the recover tablespace USERS command.  e. Issue the Startup Mount command to mount the database. f. Bring the USERS tablespace online.  g. Issue the alter database open command.  Which is the correct order of these steps in this case？（）

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

单项选择题Upon starting your database， you receive the following error：   SQL> startup ORACLE instance started.  Total System Global Area 171581440 bytes Fixed Size 1298640 bytes Variable Size 146804528 bytes Database Buffers 20971520 bytes Redo Buffers 2506752 bytes Database mounted.  ORA-00313： open failed for members of log group 1 of thread 1  ORA-00312： online log 1 thread 1： ’ oracle01 oradata orcl redo01.log’ ORA-00312： online log 1 thread 1： ’ oracle01 oradata orcl redo01a.log’   You can choose from the following steps：   a. Restore the database datafiles.  b. Issue the alter database clear unarchived logfile group 1 command. c. Issue the alter database open command.  d. Issue the alter database open resetlogs command.  e. Recover the database using point-in-time recovery. f. Issue the Startup Mount command to mount the database.  g. Back up the database.  Which is the correct order of these steps in this case？（）

A.a， f， e， d， g
B.f， e， d
C.f， b， c， g
D.a， f， c
E.The database cannot be recovered.