Peter Revesz – författare

This textbook provides students with a course in the theory of databases. It is different from others in that the author presents the subject in the framework of constraint databases which provide a natural and powerful generalization of relational databases. An important theme running through the text is to show how relational databases can smoothly develop into constraint databses and so relational database users can easily become constraint database users. Switching to constraint databases requires sacrificing none of the benefits of relational databses whilst new advantages may be realised. Peter Revesz begins by discussing data models and how queries may be addressed to these models. From this, he develops the theory of relational and constraint databases including Datalog and the relational calculus. The book then discusses three sample constraint database systems, DISCO, DINGO, and RATHER. Advanced undergraduate students and graduate students in computer science will find this a clear introduction to the subject. Professionals and researchers will appreciate this novel perspective on their subject.

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.

Introduced forty years ago, relational databases proved unusually succe- ful and durable. However, relational database systems were not designed for modern applications and computers. As a result, specialized database systems now proliferate trying to capture various pieces of the database market. Database research is pulled into di?erent directions, and speci- ized database conferences are created. Yet the current chaos in databases is likely only temporary because every technology, including databases, becomes standardized over time. The history of databases shows periods of chaos followed by periods of dominant technologies. For example, in the early days of computing, users stored their data in text ?les in any format and organization they wanted. These early days were followed by information retrieval systems, which required some structure for text documents, such as a title, authors, and a publisher. The information retrieval systems were followed by database systems, which addedeven more structure to the data and made querying easier. In the late 1990s, the emergence of the Internet brought a period of relative chaos and interest in unstructured and “semistructured data” as it wasenvisionedthateverywebpagewouldbelikeapageinabook.However, with the growing maturity of the Internet, the interest in structured data was regained because the most popular websites are, in fact, based on databases. The question is not whether future data stores need structure but what structure they need.

Introduced forty years ago, relational databases proved unusually succe- ful and durable. As a result, specialized database systems now proliferate trying to capture various pieces of the database market. The information retrieval systems were followed by database systems, which addedeven more structure to the data and made querying easier.