传输介质、（)与介质访问控制方法是决定各种局域网特性的三个要素。A．环型结构B．总线型结构C．星型

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）

A.Usesundodataforrollforward

B.UsesFlashbackLogforrecovery

C.Usesonlineredologstorollback

D.Usesundodatatorollbackthetransaction

E.UsesRecoveryManager（RMAN）torollback

F.UsestheSystemMonitor（SMON）backgroundprocesstoperforminstancerecovery

same system with the name DUPDB.You issued the following RMAN commands to create a duplicate database:Which three are the prerequisites for the successful execution of the above command?（）

A. The source database should be open

B. The target database should be in ARCHIVELOG mode if it is open

C. RMAN should be connected to both the instances as SYSDBA

D. The target database backups should be copied to the source database backup directories

E. The password file must exist for the source database and have the same SYS user password as the target

A.YoumustensurethattheSALESdatabaseismountedoropen.

B.Youmustrestoreabackupcontrolfiletoperformablockmediarecovery.

C.Youmusttakethetools01.dbfdatafileofflinebeforeyoustartablockmediarecovery.

D.YoumustputthedatabaseinNOARCHIVELOGmodetoperformablockmediarecovery.

E.Youcanperformonlyacompletemediarecoveryofindividualblocks；point-in-timerecoveryofindividualdatablocksisnotsupported.

A. SQL Access Advisor recommendations are automatically implemented.

B. Individual SQL Access Advisor recommendations can be scheduled for implementation.

C. All SQL Access Advisor recommendations for a specific task must be implemented at the same time.

D. SQL Access Advisor recommendations are automatically scheduled for implementation during the maintenance window.

E. None of the above.

Inyourdatabaseinstance，theusersessionsareconnectedtothedatabaseserverfromtheremotemachines.Youwanttoachievethefollowingfortheseusers：1.Theuseraccountmustbelockedafterfourunsuccessfulloginattempts.2.Theusermustbepromptedtochangethepasswordatregularintervals.3.Theusermaynothavemorethanthreesimultaneoussessions.4.Theusersessionmustautomaticallybeloggedoffifmorethan10minuteselapsedtimeused.Howwouldyouaccomplishtheabove（）

A.Byassigningprofilesfortheusers

B.ByimplementingFine-GrainedAuditing（FGA）

C.Bygrantingasecureapplicationroletotheusers

D.ByimplementingtheDatabaseResourceManagerplan

A. Binary data up to 4 gigabytes.

B. Character data up to 4 gigabytes.

C. Raw binary data of variable length up to 2 gigabytes.

D. Binary data stored in an external file, up to 4 gigabytes.

E. A hexadecimal string representing the unique address of a row in its table.

A.restore

B.repair

C.copy

D.recover

E.replace