Identifying dimensions and facts
When talking about a Star Schema, we automatically discuss dimensions and facts. In a Star Schema model, we usually keep all the numeric values in fact tables and put all the descriptive data in the dimension tables. But not all numeric values fall into fact tables. A typical example is Product Unit Price. If we need to do some calculations regarding the Product Unit Price, it is likely to be a part of our fact table; but if it filters or groups the data, it is a part of a dimension.
Designing a data model in a Star Schema is not possible unless we have a concrete understanding of the business requirements and a good level of understanding of the data.
Understanding business requirements
In this section, we will try to find the dimensions and facts based on the business requirements. We also discuss whether to create separate tables for them or not and why. In the following sections, we look at this in more detail and implement the required...
