单项选择题 Which tasks can be accomplished using the DBMS_LOB. SETOPTIONS procedure?（）

单项选择题 An index called ORD_CUSTNAME_IX has been created on the CUSTNAME column in the ORDERS table using the following command: SQL>CREATE INDEX ord_custname_ix ON orders(custname); The ORDERS table is frequently queried using the CUSTNAME column in the WHERE clause. You want to check the impact on the performance of the queries if the index is not available. You do not want the index to be dropped or rebuilt to perform this test.Which is the most efficient method of performing this task?（）

多项选择题 You are managing an Oracle Database 11g instance.You want to create a duplicate database for testing purpose. What are the prerequisites for performing the active database duplication?（）