Chapter 13. Dimension Role Playing

This chapter teaches you dimension role-playing, a technique you use when a fact needs a dimension more than once. For example, if the sales order fact has more than one date, say an order date and a request delivery date, you need to use the date dimension more than once.

In this chapter you also learn two types of dimension role playing implementations, table alias and database view. Both types use MySQL functions. The table alias type uses the dimension more than once in an SQL statement by assigning an alias for each use. As for the database view type, you create as many views as the number of roles you need the dimension on the fact.