When an UNDO segment is created manually by you, its availability status is set to which of the following automatically by Oracle?（）

单项选择题WhendeterminingthenumberofUNDOsegmentsinadatabase,whichofthefollowingchoicesidentifiesafactortoconsider?（）

A.Size of typical transactions 
B.Concurrent transactions 
C.Size of rows in table most frequently changed 
D.Number of anticipated disk sorts

单项选择题Youaretryingtodeterminehowmanydisksortsarehappeningonthedatabaserightnow.Whichofthefollowingdictionarytableswouldyouusetofindthatinformation?（）

A.V$SESSION 
B.V$SYSSTAT 
C.DBA_SEGMENTS 
D.V$SORT_USAGE

单项选择题Todeterminethespaceallocatedfortemporarysegments,theDBAcanaccesswhichofthefollowingviews?（）

A.DBA_TABLESPACES 
B.DBA_TABLES 
C.DBA_SEGMENTS 
D.DBA_FREE_SPACE

单项选择题Bydefault,checkpointshappenatleastasoftenas（）.

A.Redo log switches. 
B.UPDATE statements are issued against the database. 
C.The SYSTEM tablespace is accessed. 
D.SMON coalesces free space in a tablespase.

单项选择题Whichofthefollowingchoicesidentifiesadatabasecomponentthatwillbeusedfor multiplexingcontrolfiles?（）

A.V$CONTROLFILE 
B.V$DATABASE 
C.init.ora 
D.DBA FILES