Database technology is currently being pushed by the needs of new applications and pulled by the oppor- tunities of novel developments in hardware and systems architecture. The invited paper, two panel sessions and 27 papers in this volume report on how the technology is currently extending. One broad area covered is extended database semantics, including data models and data types, databases and logic, complex objects, and expert system approaches to databases. The other area covered is raw architectures and increased database systems support, including novel transaction models, data distribution and replication, database administration, and access efficiency.

The fourth international conference on Extending Data Base Technology was held in Cambridge, UK, in March 1994. The biannual EDBT has established itself as the premier European database conference. It provides an international forum for the presentation of new extensions to database technology through research, development, and application. This volume contains the scientific papers of the conference. Following invited papers by C.M. Stone and A. Herbert, it contains 31 papers grouped into sections on object views, intelligent user interface, distributed information servers, transaction management, information systems design and evolution, semantics of extended data models,accessing new media, join algorithms, query optimization, and multimedia databases.

This book constitutes the refereed proceedings of the 6th International Conference on Extending Database Technology, EDBT '98, held in Valencia, Spain, in March 1998. The 32 revised full papers presented together with one invited keynote were selected from a total of 191 submissions. The book is divided in sections on similarity search and indexing, query optimization on the Web, Algorithms for data mining, modelling in OLAP, query processing and storage management, aggregation and summary data, object-oriented and active databases, view maintenance and integrity, databases and the Web, workflow and scientific databases.

EDBT 2000 is the seventh conference in a series dedicated to the advancement of database technology. This year’s conference special theme, \Connect Millions of Users and Data Sources," underscores the importance of databases for the information age that is dawning with the new millennium. The importance - rives not just from the observation that the information age essentially rests on theconvergenceofcommunications,computing,andstorage.Equallyimportant, many of the concepts and techniques underlying the success of databasesystems have independent meaning and impact for today’s distributed information s- tems. The papers in the volume should also be seen in this light. The EDBT 2000 conference program includes 30 research papers selected by the program committee out of 187 submissions, covering advances in research, development, and applications of databases. The conference program also - cludes six industry andapplications papers,a panel discussion,six tutorials,and several software demonstrations. The conference features three distinguished - vited speakers: Ashish Gupta discusses database issues in electronic commerce, Stefano Ceri addresses the impact and challenges of XML on databases, and Andreas Reuter shares his views on new perspectives on database technology. The technical contributions presented at the EDBT 2000 conference are colle- ed and preserved in this volume that we are pleased to present to you with the expectation that it will serve as a valuable research and reference tool in your professional life.