U can create profiles and assign to the users.In a profile u can limit how much CPU to be utilised by a call,a session,sessions per user etc.
U create a profile with the follwing command
sql> create profile developer
cpu_per_call 6000/100 (hunderdts of a second)
sql> alter user scott
Before assign the profile make a change to the init.ora file and bounce back the database.
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