You work as a database administrator for Supportcenter.cn. You are using three database， SupportCenter DB01， SupportCenter DB02， and SupportCenter DB03， on different host machines in your development environment. The database server configuration， such as IP address and listener port number， change frequently due to development requirements， and you have the task of notifying the developers of the changes. Which connection method would you use to overcome this overhead？（）

多项选择题YouworkasadatabaseadministratorforSupportcenter.cn.YourdatabaseisopenedinNOARCHIVEKLOGmode.YoudecidetoplacethedatabaseinARCHIVELOGmode.Howwouldyoudothis？（）

A.Execute the ALTER DATABASE ARCHIVELOG statement
B.Select ARCHIVELOG option in the database control and restart the database to apply the changes.
C.Shut down and start the instance， and in the NOMOUNT state execute the ALTER DATABASE ARCHIVELOG statement.
D.Shut down and start the instance， mount the database， then execute the ALTER DATABASE ARCHIVELOG statement.

单项选择题YouworkasadatabaseadministratorforSupportcenter.cn.YourdatabaseisinNOARCHIVELOGmode.Thedatabasehasbeenconfiguredwiththreeredologsgroups，andtherehavebeenfivelogswitches.Youlostonenon-system-criticaldatafilefromyourdatabase.Whichmethodwouldyouusetorecoverthedatafile？（）

A.Restore all the data files and open the database
B.Create the data file and perform tablespace recovery
C.No need to restore any file， just recover the database
D.Restore only the system data file and recover the database
E.Restore only lost date file and performtablespacerecovery

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.