Angol
Differing from other books on the subject, this one uses the framework of constraint databases to provide a natural and powerful generalization of relational databases. An important theme running through the text is showing how relational databases can smoothly develop into constraint databases, without sacrificing any of the benefits of relational databases whilst gaining new advantages. Peter Revesz begins by discussing data models and how queries may be addressed to them. From here, he develops the theory of relational and constraint databases, including Datalog and the relational calculus, concluding with three sample constraint database systems -- DISCO, DINGO, and RATHER. Advanced undergraduates and graduates in computer science will find this a clear introduction to the subject, while professionals and researchers will appreciate this novel perspective on their subject.Constraint databases provide extra expressive power over relational databases in a largely hidden way at the data-storage or physical level. Constraints, such as linear or polynomial equations, are used to represent large sets in a compact manner. They keep the view of the database for a user or application programmer almost as simple as in relational databases. §"Introduction to Constraint Databases" comprehensively covers both constraint-database theory and several sample systems. The book reveals how constraint databases bring together techniques from a variety of fields, such as logic and model theory, algebraic and computational geometry, and symbolic computation, to the design and analysis of data models and query languages. Constraint databases are shown to be powerful and simple tools for data modeling and querying in application areas
