You issue this SQL command to perform an online backup of the USER_DATA tablespace：ALTER TABLESPACE user_data BEGIN BACKUP；Next， you issue an operating system command to back up user_data01.dbf， the file that belongs to the USER_DATA tablespace. You then experience an instance failure. 
Which three statements are true？（）

单项选择题WhichRMANcommandisusedtoverifythestatusofabackuporcopy，andalsoupdatestherepositorywhenfileshavebeendeletedusingoperatingsystemcommands？（）

A.CHANGE
B.RESYNC
C.CATALOG
D.CROSSCHECK

单项选择题UndertheOracleSharedServerarchitecture，client-userprocessesultimatelyconnecttoa（）

A.service
B.listener
C.dispatcher
D.shared server process

多项选择题Whichtwoaretrueregardingdirect-pathexports？（）

A.Direct-path export is typically faster.
B.Direct-path export can be invoked interactively.
C.Direct-path export is character set independent.
D.Direct-path export bypasses the SQL-command processing layer.
E.Direct-path export can be used to export rows containing LOBs and BFILEs.

单项选择题TheLogWriter（LGWR）processreadsinformationfromthe（）andwritesittotheonlinelogs.

A.large pool
B.shared pool
C.data buffer cache
D.redo log buffer
E.data dictionary cache

单项选择题WhenyouareallowingRMANtobackupyourarchivedredologfiles，howdoesRMANknowwhicharchivedredologstobackupfromyourarchivelogdestination？（）

A.RMAN keeps a list of archive logs in a text file.
B.The DBA must manually tell RMAN which archive logs to backup.
C.RMAN has access to target control file and/or catalog information.
D.RMAN looks at the ARCHIVE_LOG_DEST parameter of your target database and backs up all archive logs found.