Examine the code：  
CREATE ROLE readonly IDENTIFIES USING app.chk_readwrite ； CREATE ROLE readwrite IDENTIFIED USING app.chk_readwrite ；  
CREATE OR REPLACE PROCEDURE app.chk_readwrite
 AUTHID CURRENT_USER IS
 ipchk STRING（30）； 
BEGIN 
IF sys_context（‘USERENV’，’ISDBA’）=’TRUE’
 THEN DBMS_SESSION.SET_ROLE‘READWRITE’） ；
 ELSE DBMS_SESSION.SET_ROLE（‘READONLY’） ； 
END； /  
Which three statements correctly describe the Secure Application role definition？（）

单项选择题Consider this RMAN command：   RMAN> CONFIGURE RETENTION POLICY CLEAR；   What is the effect of this command？（）

A.Backups will never expire.
B.It removes any retention policy.
C.The DELETE OBSOLETE command will fail with an error.
D.It sets the retention policy to the default of REDUNDANCY 1.

单项选择题Examine the command：   ALTER DATABASE ADD SUPPLEMENTAL LOG DATA （PRIMARY KEY） COLUMNS；   What does the command accomplish？（）

A.Creates an additional copy of the database online redo log files. 
B.Stores the primary key column values of each row involved in a DML operation in the online redo log files. 
C.Stores the primary key column values of each row involved in a DML operation in the supplemental log files. 
D.Stores the old and new primary key column values of each row involved in a DML operation only when the primary key is modified in the online redo log files.

单项选择题Howcanyoumakeasharedserver-sideinitializationparameterfileavailabletoallinstancesofaRealApplicationClustersdatabase？（）

A.Include an SPFILE parameter in each instance-specified initialization file.
B.Create an SPFILE copy on each client from which the instance will be started.
C.Store the SPFILE in a raw partition with a vendor-specifies location and name.
D.Use a single client to start the instances and create the SPFILE on this client.

多项选择题AutomaticConsumerGroupSwitchingisanimportantnewfeatureoftheDatabaseResourceManager.Whichthreeplandirectiveparametersareusedtocontrolthisfeature？（）

A.SWITCH_TIME
B.SWITCH_GROUP
C.MAX_SESS_POOL
D.SWITCH_ESTIMATE

单项选择题You company has four DBAs. You need to know which DBA added a column to the JOB_HISTORY table. The database cannot be offline during work hours. Which LogMiner command can you use to find out which user made the table change？（）

A.A
B.B
C.C
D.D