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？（）

单项选择题 You issued the following command at the UNIX environment：   % setenv ORA_SDTZ ’OZ_TZ’   What will be the impact of issuing the above command？（）

单项选择题 YouaremaintainingyourOracle10gdatabaseintheUNIXenvironment.Anapplicationrequiresoneoftheusersessionstoexistintheoperatingsystemlocaltimezone.Youdecidetosetthetimezoneforasessionusingtheoperatingsystemenvironmentvariable.Whichcommandwillyouissue？（）