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.