Principles of Database Management The Practical Guide to Storing, Managing and Analyzing Big and Small Data

Chapter Objectives

In this chapter, you will learn to:

In this chapter we start by zooming out and reviewing the database design process. We elaborate on conceptual, logical, and physical database design. We continue the chapter with conceptual design, which aims at elucidating the data requirements of a business process in a formal way. We discuss three types of conceptual data models: the ER model; the EER model; and the UML class diagram. Each model is first defined in terms of its fundamental building blocks. Various examples are included for clarification. We also discuss the limitations of the three conceptual data models and contrast them in terms of their expressive power and modeling semantics. Subsequent chapters continue from the conceptual data models of this chapter and map them to logical and internal data models.

Phases of Database Design

Designing a database is a multi-step process, as illustrated in Figure 3.1. It starts from a business process. As an example, think about a B2B procurement application, invoice handling process, logistics process, or salary administration. A first step is requirement collection andanalysis, where the aim is to carefully understand the different steps and data needs of the process. The information architect (see Chapter 4) will collaborate with the business user to elucidate the database requirements. Various techniques can be used, such as interviews or surveys with end-users, inspections of the documents used in the current process, etc. During the conceptual design, both parties try to formalize the data requirements in a conceptual datamodel.