Building a Data Model

You already have some idea about the type of data in your database and how that data needs to be organized. This information is the beginning of a data model. Building a data model with formal notation has the following advantages:

• You think through the data model completely.

  A mental model often contains unexamined assumptions; when you formalize the design, you discover these assumptions.

• The design is easier to communicate to other people.

  A formal statement makes the model explicit, so that others can return comments and suggestions in the same form.