单项选择题
A.It is the time period after which the undo data becomes obsolete.
B.It is the time period after which the committed undo data would be transferred to a temporarytablespace.
C.It is the minimum time period up to which the committed undo data would be retained if free undo spaceis available.
D.It is the time period after which the undo data is transferred to the Flash Recovery Area to provide readconsistency.
单项选择题 InwhichsituationmaytheUNDO_RETENTIONparameterbeignored，evenifitissettoavalue（）
单项选择题 YourdatabaseinstanceisconfiguredwithautomaticundomanagementandtheUNDO_RETENTIONparameterissetto900seconds.Youexecutedthefollowingcommandtoenableretentionguarantee：SQL>ALTERTABLESPACEundotbs1RETENTIONGUARANTEE；Whateffectwouldthiscommandhaveonthedatabase（）
单项选择题 View the Exhibit and examine the undo tablespace attributes. Your database instance is experiencing a large volume of transactions from non-DBA users in the last onehour. The undo tablespace UNDOTBS1 is full with transactions and no transaction was committed morethan one hour ago. The database has two more undo tablespaces. What happens to the new DML operations in this scenario（）