In data warehouse technology, a multiple dimensional view can be implemented by a relational database technique (ROLAP), by a multidimensional database technique (MOLAP), or by a hybrid database technique (HOLAP).

a. Briefly describe each implementation technique.

b. For each technique, explain how each of the following functions may be implemented:

1.The generation of a data warehouse (including aggregation)

2.Roll-up

3.Drill-down

4.Incremental updating

d. Which implementation techniques do you prefer, and why?