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？（）

单项选择题Whatistheproperproceduretorecoveralosttempfile？（）

A. Restore the backup copy of the tempfile from the backup media.
B. Re-create the tempfile with the create tempfile command.
C. Copy an existing tempfile from another database.
D. Re-create the tempfile with the create tablespace command.
E. Re-create the tempfile with the alter tablespace command.

多项选择题WhichfilesarerequiredforafullrecoveryofthedatabaseinARCHIVELOGmode？（）

A. Database datafiles
B. Online redo logs
C. Archived redo logs
D. Backup control file
E. Control file from a backup

多项选择题Whatmethodsofpoint-in-timerecoveryareavailable？（）

A. Change-based
B. Cancel-based
C. Time-based
D. Sequence number-based
E. Transaction number-based

单项选择题Which are the correct steps， in order， to deal with the loss of an online redo log if the database has not yet crashed？（）   a. Issue a checkpoint.  b. Shut down the database.  c. Issue an alter database open command to open the database.  d. Startup mount the database.  e. Issue an alter database clear logfile command.  f. Recover all database datafiles.

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

多项选择题WhichfileswillyouneedtoperformafullrecoveryofadatabasebackedupinNOARCHIVELOGmode？（）

A. Database datafiles
B. Control files
C. Archived redo logs
D. Online redo logs
E. Flashback logs