How to identify top 10 user sessions consuming CPU time in the database
There is a famous command on UNIX and LINUX systems to list the top consumers of cpu time on the system called 'top'.
If you have the requirement to see which session in the database are the top cpu time consumers, you can use the attached SQL script to find out.
This script has been developed against 10gR2, but it works as well in 11gR2.