Sometimes When you are doing some testing on one machine and have more than one instance with limited hardware resource , Oracle let control that resource by caging its new feature in 11g its method to cage or bound the instance to use a certain number of cpu instead to take all available CPU simple way :
Alter system set CPU_Count = 2
Just as note this method work with Resource Manager so you need to enable it , and create resource manager plan first before doing Instance Caging .
- Useful when you are using multiple instance .
- Allowing CPU , Resource allocation be done effectively .
- Control CPU Consumption of each Instance .