This book constitutes the refereed proceedings of the 19th International Conference on Database and Expert Systems Applications, DEXA 2008, held in Turin, Italy, in September 2008.

Invited Talk.- Session 1.- Session 2A: Semantic Web and Ontologies.- Session 2B: Query Processing.- Session 3: Web and Information Retrieval.- Session 4: Mobile Data and Information.- Session 5: Data and Information Streams.- Session 6: Data Mining Algorithms.- Session 7: Multimedia Databases.- Session 8: Data Mining Systems, Data Warehousing, OLAP.- Session 9: Temporal, Spatial, and High Dimensional Databases II.- Session 10: Data and Information Semantics.- Session 11: XML Databases I.- Session 12: XML Databases II.- Session 13: Query Processing and Optimization.- Session 14A: Data and Information Streams.- Session 14B: Potpourri.- Session 15A: Data Mining.- Session 15B: XML Databases.- Session 16A: Applications of Database, Information, and Decision Support Systems.- Session 16B: Optimization and Performance.- Session 17: Schema, Process and Knowledge Modelling and Evolution.