Understanding object-oriented database systems -- On formalizing database updates: Preliminary report -- Concepts for graph-oriented object manipulation -- The Manchester Multimedia Information System -- Query by visual example -- Optimization of linear logic programs using counting methods -- Generalized bottom-up query evaluation -- Compilation-based list processing in deductive databases -- Multiple substitutability without affecting the taxonomy -- A view mechanism for object-oriented databases -- Theoretical aspects of schema merging -- Towards a logical-object oriented programming language for databases -- Supporting access control in an object-oriented database language -- CQL++: A SQL for the Ode object-oriented DBMS -- Retrieval of complex objects -- Evolution of knowledge bases -- The events method for view updating in deductive databases -- Implementation of delayed updates in Heraclitus -- Adaptive and automated index selection in RDBMS -- Performance of on-line index construction algorithms -- Hybrid index organizations for text databases -- Sampling issues in parallel database systems -- Parallelism for high performance query processing -- Dynamic and load-balanced task-oriented database query processing in parallel systems -- The demarcation protocol: A technique for maintaining linear arithmetic constraints in distributed database systems -- Fragmentation of recursive relations in distributed databases -- A geometric approach to indexing large rule bases -- Database support for problematic knowledge -- A knowledge-based approach to statistical query processing -- Efficient locking and caching of data in the multisystem shared disks transaction environment -- A non-restrictive concurrency control for object oriented databases -- An execution model for distributed database transactions and its implementation in VPL -- Approximate query processing with summary tables in statistical databases -- Pipelined query processing in the DBgraph storage model -- Optimizing object-oriented database queries using cost-controlled rewriting -- Panel object-oriented models for multidatabase interoperability.

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.