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YourdatabaseinstanceisconfiguredwithautomaticundomanagementandtheUNDO_RETENTIONparameteris
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YourdatabaseinstanceisconfiguredwithautomaticundomanagementandtheUNDO_RETENTIONparameterissetto900seconds.Youexecutedthefollowingcommandtoenableretentionguarantee:SQL>ALTERTABLESPACEundotbs1RETENTIONGUARANTEE;Whateffectwouldthiscommandhaveonthedatabase（）
A.Theextentsintheundotablespaceretaindatauntilthenextfulldatabasebackup.
B.Theextentscontainingcommittedundointheundotablespacearenotoverwrittenforatleast15minutes.
C.Theextentscontainingcommitteddataintheundotablespacearenotoverwrittenuntiltheinstanceisshutdown.
D.TheextentscontainingcommittedundointheundotablespacearetransferredtoFlashRecoveryAreabeforebeingoverwritten
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