A Structured Approach for the De nition of the Semantics of Active DatabasesLetizia

Altogether 22 lectures and 2 working groups covered various aspects of new trends in database languages. Areas of particular interest were foundations of database languages and extensions of the standard languages. The participants appreciated the outstanding local organization and the environment including all Dagstuhl facilities which enabled a successful workshop. The seminar has its own web-site. Today (in December 1996), it is located under the URL http://wwwdb.informatik.uni-rostock.de/dagstuhl 9610/. There, all abstracts and links, some of the slides, and further full papers are electronically available. The link has also been added to the Dagstuhl web-sites (which can be found under the URL In relational database systems, SQL has become the accepted standard as a general database language for data deenition, queries, updates, and database programming (in its embedded version). More recently, several new directions for database languages have been developed for the speciication and design of database applications, for more complex queries than expressible in standard SQL, for deeply structured and long transactions, for a seamless integration of database operations and application programs, for the use with new database models like object-oriented ones. These new directions are especially motivated by new and more-complex applications like CAD, CAM, CASE, ooce automation, and scientiic databases. These trends lead to newer versions of SQL like SQL3 and Object SQL (OQL), deductive approaches to database querying like rule-based languages or database logics, rule-based approaches for active database applications, 1 transaction languages or models for diierent data models, special-purpose speciication languages, integrated database programming languages, object-oriented calculi, algebras, or programming languages with persistence. The workshop was to bring together researchers working on foundations of database languages, especially for the relational and object-oriented database models, and researchers developing extensions of the standard languages like DATALOG and SQL, among them projects like object logic (F-Logic) or extended SQLs (SQL3, Object SQL or OQL). The discussions at the workshop aimed to result in a deeper understanding of the forthcoming developments in the database language area and the usefulness of fundamental results in complex applications. There were special sessions on developing canonical examples for advanced applications of database languages, which captured the essence of an advanced application and reported about advanced applications showing the usefulness and problems of new database languages. The language Java is enjoying a rapid rise in popularity as an application programming language. For many applications an eeective provision of database facilities is required. Here we report …