The ?rst International Symposium on the Applications of Constraint Databases (CDB2004) took place in Paris, France, on June 12–13, 2004, just before the ACM SIGMOD and PODS conferences. Since the publication of the paper “Constraint Query Languages” by Kan- lakis, Kuper and Revesz in 1990, the last decade has seen a growing interest in constraint database theory, query evaluation, and applications, re?ected in a variety of conferences, journals, and books. Constraint databases have proven to be extremely ?exible and adoptable in environments that relational database systems cannot serve well, such as geographic information systems and bioinf- matics. This symposium brought together people from several diverse areas all c- tributing to the practice and the application of constraint databases. It was a continuation and extension of previous workshops held in Friedrichshafen, G- many (1995), Cambridge, USA (1996), Delphi, Greece (1997), and Seattle, USA (1998) as well as of the work in the comprehensive volume “Constraint Data- ses” edited by G. Kuper, L. Libkin and J. Paredaens (2000) and the textbook “Introduction to Constraint Databases” by P. Revesz (2002). The aim of the symposium was to open new and future directions in c- straint database research; to address constraints over domains other than the reals; to contribute to a better implementation of constraint database systems, in particular of query evaluation; to address e?cient quanti?er elimination; and to describe applications of constraint databases.

This is the first comprehensive survey of the field of constraint databases, written by leading researchers. Constraint databases are a fairly new and active area of database research. Their ability to deal with infinite sets makes them particularly promising as a technology for integrating spatial and temporal data with standard relational databases. Constraint databases bring techniques from a variety of fields, such as logic and model theory, algebraic and computational geometry, as well as symbolic computation, to the design and analysis of data models and query languages.

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.

This is the first comprehensive survey of the field of constraint databases, written by leading researchers. Constraint databases are a fairly new and active area of database research. Their ability to deal with infinite sets makes them particularly promising as a technology for integrating spatial and temporal data with standard relational databases. Constraint databases bring techniques from a variety of fields, such as logic and model theory, algebraic and computational geometry, as well as symbolic computation, to the design and analysis of data models and query languages.

What does it take to develop an enterprise application with Rails? Enterprise Rails introduces several time-tested software engineering principles to prepare you for the challenge of building a high-performance, scalable website with global reach. You'll learn how to design a solid architecture that ties the many parts of an enterprise website together, including the database, your servers and clients, and other services as well. Many Rails developers think that planning for scale is unnecessary. But there's nothing worse than an application that fails because it can't handle sudden success. Throughout this book, you'll work on an example enterprise project to learn first-hand what's involved in architecting serious web applications. With this book, you will: Tour an ideal enterprise systems layout: how Rails fits in, and which elements don't rely on Rails Learn to structure a Rails 2.0 application for complex websites Discover how plugins can support reusable code and improve application clarity Build a solid data model -- a fortress -- that protects your data from corruption Base an ActiveRecord model on a database view, and build support for multiple table inheritance Explore service-oriented architecture and web services with XML-RPC and REST See how caching can be a dependable way to improve performance Building for scale requires more work up front, but you'll have a flexible website that can be extended easily when your needs change. Enterprise Rails teaches you how to architect scalable Rails applications from the ground up. "Enterprise Rails is indispensable for anyone planning to build enterprise web services. It's one thing to get your service off the ground with a framework like Rails, but quite another to construct a system that will hold up at enterprise scale. The secret is to make good architectural choices from the beginning. Chak shows you how to make those choices. Ignore his advice at your peril."-- Hal Abelson, Prof. of Computer Science and Engineering, MIT

The number of new applications in need of database support is exploding and there is an increasing need to link and access database systems supporting these new applications via computer networks. End-users and non-computer experts are becoming heavily involved in the set-up, management and use of database systems and this book provides the important database design methodologies and implementation technology which should be available for them as well as for computer experts.

"Addresses the evolution of database management, technologies and applications along with the progress and endeavors of new research areas."--P. xiii.