Database Design and Relational Theory : Normal Forms and All That Jazz

Create database designs that scale, meet business requirements, and inherently work toward keeping your data structured and usable in the face of changing business models and software systems. This book is about database design theory. Design theory is the scientific foundation for database design, just as the relational model is the scientific foundation for database technology in general. Databases lie at the heart of so much of what we do in the computing world that negative impacts of poor design can be extraordinarily widespread. This second edition includes greatly expanded coverage of exotic and little understood normal forms such as: essential tuple normal form (ETNF), redundancy free normal form (RFNF), superkey normal form (SKNF), sixth normal form (6NF), and domain key normal form (DKNF). Also included are new appendixes, including one that provides an in-depth look into the crucial notion of data consistency. Sequencing of topics has been improved, and many explanations and examples have been rewritten and clarified based upon the author's teaching of the content in instructor-led courses. This book aims to be different from other books on design by bridging the gap between the theory of design and the practice of design. The book explains theory in a way that practitioners should be able to understand, and it explains why that theory is of considerable practical importance. Reading this book provides you with an important theoretical grounding on which to do the practical work of database design. Reading the book also helps you in going to and understanding the more academic texts as you build your base of knowledge and expertise. Anyone with a professional interest in database design can benefit from using this book as a stepping-stone toward a more rigorous design approach and more lasting database models. You will: Understand what design theory is and is not Be aware of the two different goals of normalization Know which normal forms are truly significant Apply design theory in practice Be familiar with techniques for dealing with redundancy Understand what consistency is and why it is crucially important Create database designs that scale, meet business requirements, and inherently work toward keeping your data structured and usable in the face of changing business models and software systems. This book is about database design theory. Design theory is the scientific foundation for database design, just as the relational model is the scientific foundation for database technology in general. Databases lie at the heart of so much of what we do in the computing world that negative impacts of poor design can be extraordinarily widespread. This second edition includes greatly expanded coverage of exotic and little understood normal forms such as: essential tuple normal form (ETNF), redundancy free normal form (RFNF), superkey normal form (SKNF), sixth normal form (6NF), and domain key normal form (DKNF). Also included are new appendixes, including one that provides an in-depth look into the crucial notion of data consistency. Sequencing of topics has been improved, and many explanations and examples have been rewritten and clarified based upon the author's teaching of the content in instructor-led courses. This book aims to be different from other books on design by bridging the gap between the theory of design and the practice of design. The book explains theory in a way that practitioners should be able to understand, and it explains why that theory is of considerable practical importance. Reading this book provides you with an important theoretical grounding on which to do the practical work of database design. Reading the book also helps you in going to and understanding the more academic texts as you build your base of knowledge and expertise. Anyone with a professional interest in database design can benefit from using this book as a stepping-stone toward a more rigorous design approach and more lasting database models. What You Will Learn Understand what design theory is and is not Be aware of the two different goals of normalization Know which normal forms are truly significant Apply design theory in practice Be familiar with techniques for dealing with redundancy Understand what consistency is and why it is crucially important Who This Book Is For Those having a professional interest in database design, including data and database administrators; educators and students specializing in database matters; information modelers and database designers; DBMS designers, implementers, and other database vendor personnel; and database consultants. The book is product independent. Front Matter ....Pages i-xix Front Matter ....Pages 1-1 Preliminaries (C. J. Date)....Pages 3-21 Prerequisites (C. J. Date)....Pages 23-43 Front Matter ....Pages 45-45 Normalization: Some Generalities (C. J. Date)....Pages 47-64 FDs and BCNF (Informal) (C. J. Date)....Pages 65-95 FDs and BCNF (Formal) (C. J. Date)....Pages 97-115 Preserving FDs (C. J. Date)....Pages 117-143 FD Axiomatization (C. J. Date)....Pages 145-159 Denormalization (C. J. Date)....Pages 161-182 Front Matter ....Pages 183-183 JDs and 5NF (Informal) (C. J. Date)....Pages 185-200 JDs and 5NF (Formal) (C. J. Date)....Pages 201-219 Implicit Dependencies (C. J. Date)....Pages 221-240 MVDs and 4NF (C. J. Date)....Pages 241-260 Front Matter ....Pages 261-261 ETNF, RFNF, SKNF (C. J. Date)....Pages 263-285 6NF (C. J. Date)....Pages 287-306 The End Is Not Yet (C. J. Date)....Pages 307-315 Front Matter ....Pages 317-317 The Principle of Orthogonal Design (C. J. Date)....Pages 319-345 Front Matter ....Pages 347-347 We Need More Science (C. J. Date)....Pages 349-389 Front Matter ....Pages 391-391 What Is Database Design, Anyway? (C. J. Date)....Pages 393-406 More on Consistency (C. J. Date)....Pages 407-416 Primary Keys Are Nice but Not Essential (C. J. Date)....Pages 417-435 Historical Notes (C. J. Date)....Pages 437-441 Back Matter ....Pages 443-451