The sample source data shown in the table below provides the information about employees, their residential state, county, city and their employer names and manager names. It also describes employees working for an “American Bank” that has got many branches in several states. From data modeler point of view, analysis of the source data raises following questions.
- How to group and organize the data?
- How to avoid de-normalization since employee’s residential data like state name, county Name, city Name are repeated in most of the records.
- What sort of relationship is between employer and employee?
- What sort of relationship is between the employee and state, city, county?
Sample Source Data:
[ultimatetables 4 /]
In the next page, we will discuss how to resolve these problems in order to design a good relational data model.