单项选择题
A. when all the control files are missing and only a binary backup of the current control file exists
B. when a multiplexed copy of the current control file is missing
C. when all the control files are missing and only an ASCII representation of the binary control file exists
D. when the SPFILE is missing
多项选择题 You are the Database Administrator （DBA） of your company. You execute the following statement on an Oracle 10g instance： SQL> ALTER SYSTEM SWITCH LOGFILE； Which two tasks are performed when the statement is executed？ （）
单项选择题 You are maintaining the SALES database of TeleStar Corporation. The online redo log configuration of the database is as follows： One of the redo log members， redo3b， is lost due to disk failure. How will you recover the redo log member redo3b？（）
单项选择题 YouareusingRecoverywizardforperformingincompleterecovery.WhichofthefollowingobjecttypesisNOTavailableinthePerformRecovery：Typescreen？（）