Bøger af Lex deHaan

It is a true honor to be asked to write an introduction to a book by Lex de Haan. I just hope I can give Lex the credit he deserves for his friendship, knowledge, enthusiasm, carpentry . . . and sheer energy in the many years we've been doing things in the Oracle world. Lex spent 14 years in Oracle, starting as an instructor in Oracle Netherlands, becoming initiator and coordinator of Oracle's excellent Technical Seminar business, and finally ending up in Oracle's Curriculum Development division as a manager for a bunch of very excellent course developers. He is never afraid to start up something new, to enter new and untried waters... a personal trait he shares with about 0. 00001% of the global population. Then, finally, Lex started up for himself, and, of course, the company name had to reflect his twisted, funny way of thinking: Natural Join. Who else can get away with it, looking sto- faced and with just the slightest twinkle in his eyes, if you look really carefully? Since then Lex, as always, hasn't looked back but has worked nonstop as instructor all over Europe and the Middle East, and as writer. The book in front of you is, in fact, an update of a book he wrote many moons ago, and which has served as a textbook in various Dutch schools.

This book touches on an area seldom explored: the mathematical underpinnings of the relational database. It is the first book to explain the underlying math in a way that's accessible to database professionals.

This text is a revision of Lex de Haan's introductory book on SQL for Oracle developers and administrators. Newly updated to cover the latest Oracle features and syntax, it has been renamed "Beginning" to reflect its key position in Apress' Oracle lineup.

Relational databases hold data, right? They do indeed, but to think of a database as nothing more than a container for data is to miss out on the profound power that underlies relational technology. A far more powerful way of thinking lies in relational technologys foundation in the mathematical disciplines of logic and set theory.Databases contain truths or propositions describing some area of interest such as a business. Those truths are organized into sets. Operations from logic and set theory can be applied to existing sets of truths to derive new sets of truths. Applied Mathematics for Database Professionals introduces you to this way of thinking, to the logic and set theory that underlies relational database technology. All this may sound abstract now, but there are profound benefits from the deeper understanding youll gain from this book.The math that you'll learn in this book will put you above the level of understanding of most database professionals today. You'll better understand the technology and be able to apply it more effectively. You'll avoid data anomalies like redundancy and inconsistency. Understanding whats in this book will take your mastery of relational technology to heights you may not have thought possible.This book is reviewed and endorsed by C. J. Date and features a foreword by the same.