Advances in Databases and Information Systems

These proceedings contain 25 contributed papers presented at the 13th East- EuropeanConferenceAdvances on Databases and InformationSystems (ADBIS 2009) held September 7-10, 2009, in Riga, Latvia. The Call for Papers attracted 93 submissions from 28 countries. In a rigorous reviewing process the inter- tional Program Committee of 64 members from 29 countries selected these 25 contributions for publication in this volume; in addition, there is the abstract of an invited talk by Matthias Brantner. Furthermore, 18 additional contributions were selected for short presentations and have been published in a separate v- ume of local proceedings by the organizing institution. Topically, the accepted paperscoverawidespectrumofdatabaseandinformationsystemtopicsranging from query processing and optimization via query languages, design methods, data integration, indexing and caching to business processes, data mining, and application oriented topics like XML and data on the Web. The ADBIS 2009conference continued the series of ADBIS conferencesor- nized every year in di?erent countries of Easternand Central Europe, beginning in St. Petersburg (Russia, 1997), Poznan (Poland, 1998), Maribor (Slovenia, 1999), Prague (Czech Republic, as a joint ADBIS-DASFAA conference, 2000), Vilnius(Lithuania,2001),Bratislava(Slovakia,2002),Dresden(Germany,2003), Budapest(Hungary,2004),Tallinn(Estonia,2005),Thessaloniki(Greece,2006), Varna (Bulgaria, 2007), and Pori (Finland, 2008). The conferences are initiated and supervised by an international Steering Committee, which consists of r- resentatives from Armenia, Austria, Bulgaria, Czech Republic, Greece, Estonia, Germany, Hungary, Israel, Italy, Latvia, Lithuania, Poland, Russia, Serbia, S- vakia, Slovenia, and Ukraine, and is chaired by Professor Leonid Kalinichenko.