You work as a database administrator for Supportcenter.cn. Your database is in NOARCHIVELOG mode. The database has been configured with three redo logs groups， and there have been five log switches. You lost one non-system-critical data file from your database. Which method would you use to recover the data file？（）

单项选择题YourbossatSupportcenter.cnwantsyoutoclarifyOracle10g.Whichconditioninyourdatabaseforcesyoutoperformonlyconsistentbackups？（）

A.The database is in mount state.
B.One of the tablespaces is offline.
C.One of the tablespaces is read only.
D.The database operates in ARCHIEVELOG mode. 
E.The database operates in NOARCHIEVELOG mode.

多项选择题You work as a database administrator for Supportcenter.cn. Users in the SupportCenter PROD database complain about the slow response when accessing the database. In the Active Session Waiting： Configuration page you find that the majority of the wait time is for the redo log buffer. Further investigation using the Run Queue graph and operating system tools reveals that the redo log files are on the same disks， and that the disk I O for the redo log files is the reason for the performance degradation.  Which two actions would you take to gain performance？（）

A.Increase the size of redo log files
B.Increase the size of redo log buffer
C.Increase the number of redo log files
D.Place the redo log files on a separate disk
E.Decrease the number of redo log groups to two
F.Increate the number Log Writer （LGWR） process

单项选择题Initially，fortheAutomaticWorkloadRepository（AWR）statistics，theretentionperiodissetto7days，thecollectionintervalissetto30minutesandthecollectionlevelissettoTypicalinyourproductiondatabase.YouhavebeenusingtheMemoryAdvisorforthelastthreemonthstogeneraterecommendationsfortuningmemorycomponents.However，whenyouobservetheMemoryAdvisoronaFriday，youfindthatthestatisticsareavailableonlyfortwodays，ThursdayandFriday，ofthatweek.Whatwouldhavecausedthestatisticstoberemoved？（）

A.On Wednesday， the statistics have been purged.
B.On Wednesday， the retention period has been set to zero.
C.On Wednesday， the collection interval has been set to zero.
D.On Wednesday， the collection level has been changed to All.
E.On Wednesday， the retention period has been set to one day.
F.On Wednesday， the retention period has been set to two days
G.On Wednesday, the collection level has been changed to Typical.
H.On Wednesday, the collection interval has been set to 1440 minutes.

单项选择题Inyourdatabaseserver，theparameterPLSQL_OPTIMIZE_LEVELhasbeensetto2.Whatwouldthissettingachieve？（）

A.It degrades the run time and compiler performance.
B.It provides better run time and compiler performance.
C.It provides better optimization of the statement during parse time.
D.It forces the rule based optimizer to be used for statement optimization.
E.It provides better run time performance but slightly degraded compiler performance.
F.It provides better run time performance but slightly degraded run time performance.

单项选择题YouworkasadatabaseadministratorforSupportcenter.cn.Youfindthatreportsarerunningforalongtimeinyourdatawarehousingapplications.Yoususpectalackofindexesisthereasonfortheperformancedegradation.Whichadvisorycomponentwouldyoureferto，inordertodeterminetheappropriateindexes？（）

A.Memory Advisors
B.Segment Advisors
C.SQL Tuning and Access Advisors
D.Automated Workload Repository （AWR）
E.Automatic Database Diagnostic Monitor （ADDM）