This book provides a concise presentation of the basic principles of database design. It deals with the widely accepted core definitions and conclusions that can be precisely stated and proven. Most of the topics covered are essential to the concluding chapter on "normalization" — a knowledge of which is crucial for avoiding problematic database designs.

In addition to brevity, the structure of the book is meant to minimize page turning by making it unnecessary to flip back to previous pages. For example, to allow the reader to view all the information on a topic at once, the text appears on the left and the corresponding examples on the right of facing pages.

The book consists of five chapters as follows: The first two describe the basic techniques of modeling the real world with a database. Chapter Three covers common "operations" one can do with a database. Most of these operations pertain to using rather than designing a database; however, a few of them are also crucial for design. "Dependency and decomposition" — important in their own right and also required for the final chapter — receive a comprehensive treatment in Chapter Four. The book concludes with Chapter Five's coverage of normalization where the levels of good database design are defined along with procedures for attaining these levels. Also, problems that can occur when a database is not at a given level are described and illustrated by examples.

Table of Contents

Chapter 1 Modeling Entities 1

1.1 Tables 2
1.2 Relations 4
1.3 Keys 6

Chapter 2 Modeling Relationships 9

2.1 Foreign Keys 10
2.2 Relationships 12
2.3 Foreign Key Update Rules 14

Chapter 3 Relational Algebra 17

3.1 Unary Operators 18

Rename 18

Select 18

Project 20

3.2 Simple Binary Operators 20

Union 20

Difference 22

Intersect 22

3.3 Concatenation Operators 24

Product 24

Theta-Join 26

Equi-Join 28

Natural Join 28

Left Outer Joins 30

Right Outer Joins 34

Full Outer Joins 34

Divide 36

Summary of Operator Properties 38

Chapter 4 Dependence and Decomposition 39

4.1 Functional Dependence 40
4.2 Multivalued Dependence 44
4.3 Decomposition 46

Non-loss Decomposition 46

Independently Updateable Decomposition 48

4.4 Join Dependence 50

Chapter 5 Normalization 55

5.1 First Normal Form 56
5.2 Second Normal Form 62
5.3 Third Normal Form 64
5.4 Boyce/Codd Normal Form 68
5.5 Fourth Normal Form 70
5.6 Fifth Normal Form 72

Appendix: Proofs 77

Proofs for Chapter 3 – Relational Algebra 78
Proofs for Chapter 4 – Dependence and Decomposition 98
Proofs for Chapter 5 – Normalization 105

References 115

Index 116

Mr. Hopkins has degrees in mathematics and physics from The Ohio State University. He has worked extensively in diverse aspects of the computing field — most recently in the design and implementation of databases