From the V$SESSION_LONGOPS view， you find that some of the database users have long-running queries that consume a lot of CPU time. This causes performance problems for other users in the database， who have much shorter queries. 
You would like to make sure that the users with large queries do not use all the CPU time， but you still do not want to terminate them with an error message. 
Which method would you follow to achieve this？（）

From the V$SESSION_LONGOPS view， you find that some of the database users have long-running queries and are consuming a lot of CPU time. This causes problems for you when you try to log on as the system user and perform small maintenance tasks. You would like to ensure that users SYS and SYSTEM get priority over all other users.  
Which method would you use to achieve this objective？（）