单项选择题 You have 100 segments in the USERS tablespace. You realize that the USERS tablespace is running low on space.  You can use Segment Advisor to （）

单项选择题 The Automatic Database Diagnostic Monitor （ADDM） analysis runs every 60 minutes on your database. Your database is facing a series of interrelated problems over a period of two hours. You need to ensure that the ADDM analysis is run over a time span of two hours in future.  What would you do？（）

多项选择题 The EMP table exists in your schema. You want to execute the following query：   SELECT ename， sal FROM emp AS OF TIMESTAMP （SYSTIMESTAMP - INTERVAL ’6’ MINUTE）   WHERE ename = ’ALLEN’；   What are the minimum requirements for the statement to execute successfully？（）