单项选择题 Your Oracle10g database contains a table with a TIMESTAMP TO LOCAL TIME ZONE column. There are about two hundred column values for the column. You issued the following statement：   SQL> ALTER DATABASE SET TIME_ZONE =’Europe/London’；   What will be the result of issuing the above statement？（）

单项选择题 You are maintaining your database in Oracle10g. You find that the number of languages that should be supported in your database has increased. The character set of your database is UTF8. You decide to migrate your database to the AL16UTF16 national character set.   How will you migrate your database from UTF8 to AL16UTF16？（）

单项选择题 Click the Exhibit（s） button to view the EMPLOYEES table.      The EMPLOYEE table contains thousands of rows. The EMP_CODE column is the primary key column. At the end of every month， you are required to perform search queries based on the BASIC_SAL+COMM column values. Which type of index will you create？（）