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Reviewer: R. B. Abhyankar

The field at the interface of logic programming and data bases, known by such names as “deductive database systems,” “expert database systems,” and “knowledge-base systems,” has advanced tremendously in recent years. Most of the published material on the topic is scattered through journal articles and conference proceedings. This book provides a much-needed survey of the field. The book consists of 12 chapters. Chapter 1 provides an overview of logic programming and databases. Chapter 2 reviews relational databases and Prolog. The remaining chapters are grouped into three parts. Part 1, “Coupling Prolog to Relational Databases,” consists of chapters 3, 4, and 5. Chapter 3 deals with Prolog as a query language. Chapter 4 covers loosely coupled systems, tightly coupled systems, caching of data and queries, use of subsumption, and parallelism. Chapter 5 presents an overview of prototype systems for coupling Prolog to relational databases. Part 2, “Foundations of Datalog,” consists of chapters 6 and 7. Chapter 6 deals with the syntax and semantics of Datalog. Chapter 7 covers the proof theory and evaluation paradigms of Datalog: the bottom-up or forward-chaining paradigm, the top-down or backward-chaining paradigm, and the least-fixpoint-iteration paradigm. Part 3, “Optimization Methods for Datalog,” consists of chapters 8 through 12. Chapter 8 discusses the classification of optimization methods for Datalog, translation of Datalog into relational algebra, the classification of Datalog rules, and the expressive power of Datalog. Chapters 9 and 10 deal with several optimization methods for Datalog in detail—chapter 9 covers evaluation methods and chapter 10 covers rewriting methods. Chapter 11 presents extensions of Datalog, including the use of built-in functions, incorporation of negation into Datalog, and the representation and manipulation of complex objects. Chapter 12 is an overview of research prototypes for integrating relational databases and logic programming. The book also contains an extensive bibliography and an index. The book contains a large number of examples and exercises. It is suitable as a textbook at the advanced undergraduate or beginning graduate level. A small number of other books (such as Lloyd [1], Naqvi and Tsur [2], and Ullman [3]) also deal with some of the topics discussed in this book, but this volume provides the most balanced treatment of the major aspects of the field. It is not an exhaustive survey of the entire field, however: the authors do not address semantic query optimization, the validation of integrity constraints, or the treatment of incomplete information. In spite of this, the book is an excellent and much-needed addition to the literature on logic programming and databases.