These are the proceedings of the third International conference on ExtendingDatabase Technology (EDBT) held in Vienna in March 1992. The success of the 1988 and 1990 conferences held in Venice suggested that there is room for a major international database conference in Europe every two years, to serve as a forum for presentation of new results in research, developmentand applications extending the state of the art in database technology. The 1992 EDBT conference has attracted a lot of interest. This volume contains 33 papers selected from 220 papers submitted by authors from more than 30 countries, including invited papers by F. Bancilhon and R. Reiter. The volume is organized into sections on: visual interfaces and multimedia techniques, deductive databases, schema updatability, object-oriented databases, updating in deductive databases and knowledge bases, indexing techniques, parallel processing, distributed databases, knowledge bases, transaction processing, and query processing.

This volume is the proceedings of the Second International Conference on Deductive and Object-Oriented Databases (DOOD). During the last decade, deductive and object-oriented systems have received a great deal of attention, but for the most part these two fields were evolving independently of each other. Today there is a large body of work suggesting that the deductive and object-oriented paradigms complement each other. The object-oriented paradigm is characterized by its view of the data, whereby information is grouped around objects with complex internal structure accessed via methods. The declarative paradigm is centered around the idea that data manipulation must be done through a declarative, logic-based language. It is hoped that these two aspects, brought together in one system, will provide an integrated framework fora new database technology. The DOOD conference brings together researchers and developers in the fields of deductive and object-oriented databases to stimulate technical discussion and accelerate the integration of the two technologies. This volume contains 28 contributed papers (selected from 98 submissions) and two invited papers by world-renowned researchers.