Please rtefer to the following link:
http://www.cryer.co.uk/brian/oracle/howto_orcl_rbai.htm
For better, quicker answers on T-SQL questions, click on the following...
http://www.sqlservercentral.com/articles/Best+Practices/61537/
For better answers on performance questions, click on the following...
http://www.sqlservercentral.com/articles/SQLServerCentral/66909/