单项选择题
A. The block change tracking feature must be enabled.
B. OMF must be configured on your database.
C. The database must be in ARCHIVELOG mode.
D. A USERID must be supplied.
单项选择题 YouaremaintainingthePRODdatabaseofTeleSoftCorporation.YouhaveinitializedthefollowingDB_BLOCK_CHECKINGparameterintheinit.orafile：DB_BLOCK_CHECKING=TRUE；Whatwillbetheresultofsettingthisparameter？（）
单项选择题 YouareusingtheBlockMediaRecoveryfeaturetorecovertheblocksthataremarkedcorruptsincethelastbackup.Whichviewwillyouquerytodisplayinformationaboutthedatablocksthataremarkedcorruptsincethelastbackup？（）
单项选择题 YouaremaintainingyourOLTPdatabaseinOracle10g.YouareperformingtheFlashbackTransactionQuerytofindtheundoSQLstatementsthatcanbeusedtoundothechangesmadetothedatabaseinthespecifictimeperiod.WhichpseudocolumnwillyouusetoperformtheFlashbackTransactionQuery？（）