The EDBT/ICDT2007 Joint conference took place on March 22-26, 2009 at the Saint-Petersburg University, Russia. Both EDBT, the International Conference on Extending Database Technologies, and ICDT, the international Conference on Database Theory, are well established premier forums for database researchers and practitioners. The joint EDBT/ICDT was an exciting conference, discussing original results on all aspects of data management as well as keynote talks, tutorials, and demonstrations that presented the most critical issues and views on leading-edge database theory, technology, applications, and techniques. Continuing the tradition of EDBT, the joint conference hosted a series of workshops that cover important aspects in the thematic context of data bases. This volume contains final post-workshop versions of papers presented at all workshops co-located with joint EDBT/ICDT conference: ?DAMAP09 Second International Workshop on Data Management in Peer-to-peer systems ?DataX'09: Fourth International Workshop on Database Technologies for Handling XML Information on the Web ?Privacy and Anonymity in the Information Society (PAIS) ?Joint EDBT/ICDT Ph.D. Workshop 2009. The organizers/chairs of each workshop provided their own forewords, and, of course, workshops had separate program committees, all listed as a front matter of this volume, followed by the research contributions.