Date on Database

About the Author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxv
PART 1 ■ ■ ■ Some Preliminaries
■CHAPTER 1 Edgar F. Codd: A Tribute and Personal Memoir . . . . . . . . . . . . . . . . . 3
■CHAPTER 2 An Interview with Chris Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
■CHAPTER 3 Good Writing Does Matter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
PART 2 ■ ■ ■ And Now for Something
Completely Different
■CHAPTER 4 On the Notion of Logical Difference . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
■CHAPTER 5 On the Logical Difference Between Model
and Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
■CHAPTER 6 On the Logical Differences Between Types, Values,
and Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
PART 3 ■ ■ ■ Relational Database Management
■CHAPTER 7 Why We Need Type BOOLEAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
■CHAPTER 8 What First Normal Form Really Means . . . . . . . . . . . . . . . . . . . . . . . 107
■CHAPTER 9 A Sweet Disorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
■CHAPTER 10 Double Trouble, Double Trouble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
■CHAPTER 11 Multiple Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
■CHAPTER 12 Data Redundancy and Database Design . . . . . . . . . . . . . . . . . . . . . . 217
■CHAPTER 13 Data Redundancy and Database Design:
Further Thoughts Number One . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255

■CHAPTER 14 Tree-Structured Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
■CHAPTER 15 Twelve Rules for Business Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
PART 4 ■ ■ ■ SQL Database Management
■CHAPTER 16 Two Remarks on SQL’s UNION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
■CHAPTER 17 A Cure for Madness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
■CHAPTER 18 Why Three- and Four-Valued Logic Don’t Work . . . . . . . . . . . . . . . 329
PART 5 ■ ■ ■ Further Relational Misconceptions
■CHAPTER 19 There’s Only One Relational Model . . . . . . . . . . . . . . . . . . . . . . . . . . 345
■CHAPTER 20 The Relational Model Is Very Much Alive! . . . . . . . . . . . . . . . . . . . . 361
■CHAPTER 21 What Do You Mean, “Post-Relational”? . . . . . . . . . . . . . . . . . . . . . . 369
■CHAPTER 22 A Database Disconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
PART 6 ■ ■ ■ Subtyping and Inheritance
■CHAPTER 23 Is a Circle an Ellipse? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
■CHAPTER 24 What Does Substitutability Really Mean? . . . . . . . . . . . . . . . . . . . . . 409
PART 7 ■ ■ ■ Relational vs. Nonrelational Systems
■CHAPTER 25 Models, Models, Everywhere, Nor Any Time to Think . . . . . . . . . . 437
■CHAPTER 26 Basic Concepts in UML: A Request for Clarification . . . . . . . . . . . 445
■CHAPTER 27 A Comparison Between ODMG and The Third Manifesto . . . . . . . 457
■CHAPTER 28 An Overview and Analysis of Proposals Based on
the TSQL2 Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481
■APPENDIX The Role of the Trade Press in Educating the
Professional Community: A Case Study . . . . . . . . . . . . . . . . . . . . . . 515
■INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527