You just completed a manual open database backup. However there seems to be a problem with the database performance. You discover that the database is generating many log switches and the LGWR is consuming lots of CPU time. You have an idea of what the problem is and you begin looking at the information in V$BACKUP and in V$DATAFILE_HEADER.
What do you suspect is the problem？（）

单项选择题Examine this statement：  RMAN >BACKUP FORMAT ’ BACKUP df_%d_%s_%p.bus1 DATABASE filesperset = 2；  What state must the target database be in for you to use this RMAN command？（）

A.The target database must be open.
B.The target database must be closed.
C.The target database must be mounted.
D.The target database must be mounted or open.

单项选择题WhenyouusetheOracleNetConfigurationAssistanttospecifythenamingmethod，whichfileisupdated？（）

A.INIT.ORA
B.SQLNET.ORA
C.LISTENER.ORA
D.TNSNAMES.ORA

单项选择题WhenissuingtheCROSSCHECKcommandinRMAN，ifabackupfileCANNOTbefound，towhatstatusisthatfileset？（）

A.DELETED
B.OBSOLETE
C.EXPIRED
D.UNKNOWN

单项选择题YourdatabaseissetinNOARCHIVELOGmodeandisbackedupeverynight.Thereare10redologgroupsonthedatabase，eachwiththreemembers，makingatotalof30redologfiles.Atlunchtimetheserverunexpectedlygetsshutdown.UponrestartingyounoticethatthedatafilebelongingtotheSYSTEMtablespacehasbecomecorrupted.Youalsonoticethattherehavebeen15logswitchesduringtheday.Whichsolutionshouldyouusetorecoverasmuchcommitteddataaspossible？（）

A.Restore the data file for the SYSTEM tablespace then open the database. 
B.Restore all redo logs form last night's backup, then restart the database. 
C.Perform a complete restore of all files from last night's backup. Data entered into the database today must be reentered. 
D.Mount the instance, take the SYSTEM tablespace offline, open the database, and then restore the data file, recover it, and bring the tablespace online. 

单项选择题You have configured the following：  RMAN> CONFIGURE DEFAULT DEVICE TYPE TO ’sbt’； new RMAN configuration parameters：  CONFIGURE DEFAULT DEVICE TYPE TO ’sbt’； new RMAN configuration parameters are successfully stored RMAN> SHOW DEVICE TYPE； RMAN configuration parameters are： CONFIGURE DEVICE TYPE SBT PARALLELISM 1； # CONFIGURE DEVICE TYPE DISK PARALLELISM 1； #  RMAN> CONFIGURE DEVICE TYPE SET PARALLELISM 5；  RMAN> SHOW DEVICE TYPE； RMAN configuration parameters are： CONFIGURE DEVICE TYPE SBT PARALLELISM 5； CONFIGURE DEVICE TYPE DISK PARALLELISM 1； #  How many channels are allocated to SBT？（）

A.0， because channels have not been defined.
B.3， as indicated by the degree of parallelism.
C.1， the default value when device is configured.
D.5， as indicated by the last parallelism command.