Active rules provide a new and important method for designing databases and the subject is seeing an increasing amount of attention from commercial database companies. This book provides a timely survey of the field from the point of view of some of the subject's most active researchers. The book is divided into several parts, organized by theme: the first, Fundamentals covers the underlying methodology reagrding active rules, next comes a collection of chapters which cover formal specification, rule analysis, performance analysis, and support tools, the third part is devoted to a number of chapters covering the implementation of active rules in a number of commercial systems. Finally, come sections on applications and future directions that research may take. All researchers in databases will find this provides a valuable overview of this topic.