Initially， for the Automatic Workload Repository （AWR） statistics，the retention period is set to 7 days， the collection interval is set to 30 minutes and the collection level is set to Typical in your production database. You have been using the Memory Advisor for the last three months to generate recommendations for tuning memory components. However，when you observe the Memory Advisor on a Friday，you find that the statistics are available only for two days， Thursday and Friday，of that week. What would have caused the statistics to be removed？（）

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）

单项选择题Twodatabaseusers,JackandBill,areaccessingtheSupportCenterSTAFFtableoftheSupportCenterDBdatabase.WhenJackmodifiesavalueinthetable,thenewvalueisinvisibletoBill.WhichisthemodifiedvalueinvisibletoBill?（）

A.The modified data are not available on disk.
B.The modified data have been flushed out from memory.
C.The modified rows of the SupportCenter STAFF table have been locked.
D.Jack has not committed the changes after modifying the value.
E.Both users are accessing the database from two different machines.

多项选择题YouworkasadatabaseadministratorforSupportcenter.cn.YouhavesettheretentionperiodforAutomaticRepository（AWR）statisticstofourdaysandcollectionintervalto15minutes.YouwanttoviewthestatisticscollectedandstoredinAWRsnapshot.WhichtwomethodswouldyouusetoviewtheAWRstatistics？（）

A.use enterprise manager
B.use DBMS_SQL package
C.use DBMS_AWR package
D.use PRVT_WORKLOAD package
E.query the AWR snapshot repository objects
F.use DBMS_WORKLOAD_REPOSITORY package

单项选择题YouworkasadatabaseadministratorforSupportcenter.cn.Inaproductionenvironment，userscomplainabouttheslowresponsetimewhenaccessingthedatabase.YouhavenotoptimizedthememoryusageoftheOracleinstanceandyoususpecttheproblemtobewiththememory.Towhichtypeofobjectwouldyourefertodeterminethecauseoftheslowresponse？（）

A.The trace file
B.The fixed views
C.The data dictionary views
D.The operating system log fields
E.The dynamic performance views.