Which three resource plan parameters are used to enable Automatic Consumer Group Switching to estimate job execution times automatically， and to perform a switch to a low priority consumer group before they are initiated？（）

单项选择题Thedatabasewasstartedupusingatextparameterfile.WhatwillbethedefaultscopeofchangesmadebyusingtheSETclauseoftheALTERSYSTEMstatement？（）

A.Only MEMORY is updated.
B.Only SPFILE values are updated.
C.Only init.ora parameters are updated.
D.Both init.ora parameters and SPFILE values are updated.

多项选择题Which two are regarding automatic space management segments？（）

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

多项选择题Media recovery can sometimes be stopped by the inability to read past a certain point in the redo stream. This is often referred to as “stuck recovery”. Before Oracle9i， the  Database Administrator had few options to deal with stuck recovery. If the corrupt redo could not be recovered from some other source， then all transactions that committed after the corrupt point in the redo steam would be lost.  Oracle9i changes that with the Trial Recovery feature. Trial Recover is used to test the application of the redo logs to the database.  What are three other characteristics of Trial Recovery（）

A.Speeds up subsequent media recover actions.
B.Writes any uncorrupted block to disk during the test recovery.
C.Can be invoked by adding the TEST option to any RECOVER command.
D.Allows the Administrator to determine how many blocks are affected by corruption.
E.Marks blocks as corrupt in memory， allowing the test recover to proceed to completion.

多项选择题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？（）

A.No user or application has to remember or hide a password. 
B.It prevents everyone except a true DBA session from acquiring the READWRITE role. 
C.app.chk_readwrite is called whenever a user tries to access rows protected by the READONLY or READWRITE label. 
D.app.chk_readwrite is called by users or applications when they want to enable the READONLY or READWRITE role.

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.