单项选择题
A. when a table is dropped and stored in the Recycle Bin
B. when all the control files are deleted
C. when a member of a multiplexed redo log group is dropped
D. when you are required to recover a table to its previous state
单项选择题 You are working as a DBA in a company. The datafiles in the database are as follows： On Monday， you tried to start up the database but failed because all the control files were missing. You recreated the control file using the script you have created by issuing the ALTER DATABASE BACKUP CONTROLFILE TO TRACE command. What is the prerequisite for recreating the control file？（）
单项选择题 YourdatabaseisinARCHIVELOGmode.Youlostanindextablespaceduetoadiskfailurewhilethedatabasewasopen.YouhaveneitherabackupofthelostindextablespacenorthescriptscontainingtheCREATEINDEXstatementstorecreatetheindexes.Currently，severalusersareexecutinglong-runningqueriesonthedatabase.Whatwillhappentotheongoingactivityinthedatabase？（）
单项选择题 YouaremaintainingyourdatabaseinOracle10g.YoufindthattheINDEXESindextablespaceshouldberecovered.Howwillyourecovertheindextablespace？（）