单项选择题
A.Group 2 is the active group.
B.Group 2 is the current group.
C.Database is in the MOUNT state.
D.Group 2 has been already archived.
单项选择题 You are working on a very large database. You had performed a binary backup of the control file a month ago. After this you added a few tablespaces， and dropped a couple of tablespaces. This morning， due to hardware failure， you lost all your control files. How would you recover the database from this situation？（）
单项选择题 IntheinstanceofthePRODdatabase，thecheckpoint（CKPT）processrunsaftereveryminute.AdatabaseuserupdatestherowsoftheORDERStable.Becauseoftheconfiguration，theCKPTprocessgetsinitiatedbeforetheusercommitsthetransaction.WhatwouldhappentothemodifiedblockswhentheCKPTprocessisstarted？（）
单项选择题 UsersinyourPRODdatabasecomplainabouttheslowresponseofthetransactions.Whileinvestigatingthereason，youfindthatthetransactionsarewaitingfortheundosegmentstobeavailable，andundoretentionhasbeensettozero.Whatwouldyoudotoovercomethisproblem？（）