You want to monitor and control the resource usage by sessions. You want to be warned automatically when more than 100 sessions are opened with your database. What action would you take to achieve this？（）

多项选择题WhichtwostatementsregardingtheLOGGINGclauseoftheCREATETABLESPACE...statementarecorrect？（）

A.This clause is not valid for a temporary or undo tablespace.
B.If the tablespace is in the NOLOGGING mode，no operation on the tablespace will generate redo.
C.The tablespace will be in the NOLOGGING mode by default，if not specified while creating a tablespace.
D.The tablespace-level logging attribute can be overridden by logging specifications at the table，index， materialized view，materialized view log，and partition levels.

单项选择题WhichtwooperationscanbeflashedbackusingtheFlashbacktechnology？（）

A.DROP USER SMITH；
B.DROP TABLE EMPLOYEES；
C.DROP TABLESPACE USERS；
D.ALTER TABLE SALES_REP DROP PARTITION P1；
E.ALTER TABLE EMPLOYEES DROP COLUMN DESIG_ID；

单项选择题Yourdatabaseishavingtwocontrolfiles，threeredologfilegroupswithtwomembersineachgroup.Failureofwhichfilewouldcauseaninstancetoshutdown？（）

A.any control file
B.any archive log file
C.one of the redo log members
D.loss of the initialization parameter file
E.any data file belonging to the default permanent tablespac

单项选择题Youhavebeenrecentlyhiredasadatabaseadministrator.YourseniormanagerasksyoutostudytheproductiondatabaseserverandsubmitareportonthesettingsdonebythepreviousDBA.Whileobservingtheserversettings，youfindthatthefollowingparameterhasbeensetintheparameterfileofthedatabase：REMOTE_OS_AUTHENT=TRUEWhatcouldhavebeenthereasontosetthisparameterasTRUE？（）

A.to enable operating system authentication for a remote client
B.to restrict the scope of administration to identical operating systems
C.to allow the start up and shut down of the database from a remote client
D.to enable the administration of the operating system from a remote client
E.to disable the administration of the operating system from a remote client

单项选择题Your database is open and users are connected using the LISTENER listener. The new DBA of the system stops the listener by using the following command：  LSNRCTL> STOP  What would happen to the sessions that are presently connected to the database instance？（）

A.The sessions are able to perform only queries.
B.The sessions are not affected and continue to function normally.
C.The active transactions are rolled back and the sessions get terminated.
D.The sessions are not allowed to perform any operations till the listener is started.