单项选择题
A. Enable flashback logging.
B. Start the database in the ARCHIVELOG mode.
C. Issue the ALTER DATABASE FLASHBACK ON； command.
D. Set the FAST_START_MTTR_TARGET initialization parameter.
多项选择题 Youwanttoenforceacompany’sbusinesspolicyonseveralobjectsbyusingasinglepolicyfunction.Whichtwotypesofpoliciescanbeassignedtothepolicy_typeargumentinthedbms_rls.add_policyproceduretoachievetheaboveobjective？（）
单项选择题 Youenabledblockchangetrackingforfasterincrementalbackupsinyourdatabase.Whichbackgroundprocesswritestothechangetrackingfile？（）
多项选择题 WhichsixfilesaremaintainedintheFlashRecoveryArea？（）