What is drill down and roll up?
Drill down corresponds to choosing a subconcept of the current concept involved into the OLAP dimension. Thus we move to more detailed view because subconcepts have more detailed items. Roll up is an opposite operation of moving to a superconcept of the current concept. Thus changing the current concept we can the level of details. Generally there are more than one superconcept and subconcept defined for an OLAP dimension so the choice may be more complex.
