While connected to the database，a user on a PC receives a fatal error and the machine reboots. Which background process cleans up the failed connection？（）

多项选择题YounoticethatyourRMANscriptusedtocopythedatafiles，controlfiles，andarchivedredologfilesisperformingveryslowly.WhichtwochangesmightyouwanttoincludeinyourRMANscripttospeeduptheCOPYcommands？（）

A.NOCHECKSUM
B.MAXCORRUPT
C.CHECK LOGICAL
D.BACKUP INCREMENTAL
E.CONFIGURE DEVICE TYPE ... PARALLELISM

单项选择题Whichstatementistrueregardingremotearchivelogfiledestinations？（）

A.Only two destinations per remote database can be specified.
B.Destination is an Oracle Net alias specified by using the SERVICE keyword.
C.The REOPEN attribute must be used when using remote archive log file destinations.
D.The service name is resolved by searching sqlnet.ora file for the remote database name.

多项选择题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？（）

A.A
B.B
C.C
D.D
E.E

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