Identifying dimensions and facts
When we are talking about a Star Schema, we are automatically talking about 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 a part of our fact table. However, if the Product Unit Price is used to filter or group the data, it is probably a part of a dimension.
Designing a data model in a Star Schema is not possible unless we have a level of understanding of the data. This chapter aims to look at the Chapter 6, Sales Data.xlsx data and create a Star Schema.
As we mentioned earlier, to create a Star Schema, we need to have a closer look at the data we are going to model and identify dimensions and facts. In this section, we will try to find these dimensions and facts...
