数据链路层的功能不包括（)A．数据转换B．链路管理C．差错控制D．流量控制

seofthechangestothephysicalstructureofyourdatabase，youperformedabackupofthecontrolfiletotrace.Afterthis，youlostonlythecontrolfilesandtheinstanceabortedduetoahardwarefailure.Howwouldyouproceedtorecoverthedatabase？（）

A.Starttheinstanceandopenthedatabase，instancerecoveryautomaticallyrecoverscontrolfiles

B.Createafilebasedonthecontentsofthetracefileandsaveittothecontrolfilelocationsandstartthedatabase

C.Re-createthedatabase（Therecoveryofthecontrolfileisnotpossiblebecauseyouhavelostallthecontrolfiles.）

D.Starttheinstance，intheNOMOUNTstate，re-createthecontrolfileusingtheCREATECONTROLFILEcommandstoredinthetracefile.

E.StarttheinstanceandMOUNTthedatabase，thenre-createthecontrolfileusingtheCREATECONTROLFILEcommandstoredinthetracefile.

t to perform user managed backup for the data files of the HR_DATA tablespace.To accomplish the task, you issued the following command:SQL> ALTER TABLESPACE hi_data BEGIN BACKUP;Which two statements are true in this scenario? （）

A. No transaction on the tablespace is allowed but you can perform queries.

B. The tablespace will automatically come out of backup mode when the file copy is complete.

C. The checkpoint change number is frozen in headers of the data files until the file is removed from backup mode.

D. The database writes the before image of an entire block to the redo stream before modifying. block tor the first time.

Observetheinformationinthecolumns：1.TheSGAa.TextandparsedformsofallSQLstatements2.Thecursorstateb.Run-timememoryvaluesfortheSQLstatement，suchasrowsretrieved3.User-sessiondatac.Securityandresourceusageinformation4.Thestackspaced.LocalvariablesfortheprocessWhichoptionhasthecorrectmatchbetweenthememoryareasandtheircontents（）

A.1-c，2-b，3-d，4-a

B.1-b，2-c，3-d，4-a

C.1-a，2-b，3-c，4-d

D.1-a，2-b，3-d，4-c

A. Create a table view.

B. Create a view in any schema.

C. Create a view in your schema.

D. Create a sequence view in any schema.

E. Create a view that is accessible by everyone.

F. Create a view only of it is based on tables that you created.

sethelistenerisnotresponding.Youwanttoforwardclientconnectrequeststoanotherlistenerifonelistenerisnotresponding.Howdoyouachievethis？（）

A.Enableinstancefailover

B.Configuresharedserver

C.Enabledatabasefailover

D.Enableconnect-timefailover

E.EnableTransparentApplicationFailover（TAF）

A. Segment Advisor

B. SQL Access Advisor

C. Optimizer statistics gathering

D. Automatic SQL Tuning Advisor

E. Automatic Database Diagnostics Monitor

ecustomertableisbeingaccessedbysomeunauthorizedusers.Whichoptionwouldyouusetomonitorthequeriesbeingexecutedonthecustomertable？（）

A.Monitorthealert.logfile

B.Enableserver-sideSQLtracingforusersessions

C.Enablefine-grainedauditingforthecustomertable

D.EnableFine-GrainedAccessControl（FGAC）forthecustomertable

E.WriteadatabasetriggeronthecustomertableontheSELECTevent

A. You cannot roll back this statement.

B. All pending transactions are committed.

C. All views based on the DEPT table are deleted.

D. All indexes based on the DEPT table are dropped.

E. All data in the table is deleted, and the table structure is also deleted.

F. All data in the table is deleted, but the structure of the table is retained.

G. All synonyms based on the DEPT table are deleted.

A. selection of SQL plan baselines

B. partitioning of tables and indexes

C. creation of index-organized tables

D. creation of bitmap, function-based, and B-tree indexes

E. optimization of materialized views for maximum query usage and fast refresh

A.LargePool

B.RedoLogBuffer

C.DatabaseBufferCache

D.ProgramGlobalArea（PGA）