This book presents a unified collection of concepts, tools, and techniques that constitute the most important technology available today for the design and implementation of information systems. The framework adopted for this integration goal is the one offered by the relational model of data, its applica tions, and implementations in multiuser and distributed environments. The topics presented in the book include conceptual modeling of application environments using the relational model, formal properties of that model, and tools such as relational languages which go with it, techniques for...