Databases and database systems in particular, are considered as kerneIs of any Information System (IS). The rapid growth of the web on the Internet has dramatically increased the use of semi-structured data and the need to store and retrieve such data in a database. The database community quickly reacted to these new requirements by providing models for semi-structured data and by integrating database research to XML web services and mobile computing. On the other hand, IS community who never than before faces problems of IS development is seeking for new approaches to IS design. Ontology­ based approaches are gaining popularity, because of a need for shared conceptualisation by different stakeholders of IS development teams. Many web-based IS would fail without domain ontologies to capture meaning of terms in their web interfaces. This volume contains revised versions of 24 best papers presented at the th 5 International Baltic Conference on Databases and Information Systems (BalticDB&IS'2002). The conference papers present original research results in the novel fields of IS and databases such as web IS, XML and databases, data mining and knowledge management, mobile agents and databases, and UML based IS development methodologies. The book's intended readers are researchers and practitioners who are interested in advanced topics on databases and IS.