Steps in dimensional modeling
As with normalizing data, we can distinguish some formal steps that lead to a data model. Unlike with normalizing data, these steps are used in an iterative approach. The process of designing the star schema leads to new insights that might mean that you have to go back one step. The steps that you need to take are as follows:
- Choose a process and define the scope.
- Determine the needed grain.
- Determine the dimensions.
- Determine the facts.
Choosing a process and defining the scope
As we already said during Entity Analysis (Chapter 2, Entity Analysis), it is easy to get carried away and model the entire world. Make a clear choice in what the goal of the star schema is. Remember that a single star schema models a single process. A business process can be defined as a set of activities and tasks that, once completed, will accomplish an organizational goal. Examples are sales, marketing, human resources, and so on. The ultimate...