创建派生属性的最佳方式是什么

I have a datamodel with to-many to-many relations. Using the example of employee database let say the entity division is related to department which in turn is related to employee. The employee has an attribute salary. How best to have a attribute at the level of division which is derived from the salary attribute. For example average salary or maximum salary.I have a datamodel with to-many to-many relatio