Database Concepts

Abstract

This chapter introduces the basic database concepts, covering modeling, design, and implementation aspects. Section 2.1 begins by describing the concepts underlying database systems and the typical four-step process used for designing them, starting with requirements specification, followed by conceptual, logical, and physical design. These steps allow a separation of concerns, where requirements specification gathers the requirements about the application and its environment, conceptual design targets the modeling of these requirements from the perspective of the users, logical design develops an implementation of the application according to a particular database technology, and physical design optimizes the application with respect to a particular implementation platform. Section 2.2 presents the Northwind case study that we will use throughout the book. In Sect. 2.3, we review the entity-relationship model, a popular conceptual model for designing databases. Section 2.4 is devoted to the most used logical model of databases, the relational model. Finally, physical design considerations for databases are covered in Sect. 2.5.

The aim of this chapter is to provide the necessary knowledge to understand the remaining chapters in this book, making it self-contained. However, we do not intend to be comprehensive and refer the interested reader to the many textbooks on the subject.