The 3rd Eastern European Conference on Advances in Databases and Information Systems (ADBIS 99) took place on 13-16- September 1999, in Maribor, Slovenia. It was organized in cooperation with ACM SIGMOD, the Moscow chapter of ACM SIGMOD, Slovenian Society Informatika, and the Slovenian Ministry of Technology. The aim of the ADBIS series of conferences is to provide a forum for the exchange of scientific achievements and experiences using innovative methods and approaches between the research communities of Central and Eastern Europe and the rest of the world in the area of databases and information systems. The 1999 conference continues the series of ADBIS events held in Moscow, St. Petersburg, and Poznan. The ADBIS steering committee has the ambition to make the ADBIS conference the premiere database and information systems conference in Central and Eastern Europe, to increase interaction and collaboration between researchers from East and West, and to provide an internationally recognized forum for the presentation of research and experiences in all aspects of modern database technology and information systems. To achieve these goals an international program committee selected 26 full research papers in a rigorous reviewing process from a total of 94 submissions from 33 different countries. This high number of submissions from so many different areas shows the truly worldwide recognition of and interest in the ADBIS series."