Invited Talk -- Design Issues and Challenges for RDF- and Schema-Based Peer-to-Peer Systems -- Structure in P2P Networks -- SIL: Modeling and Measuring Scalable Peer-to-Peer Search Networks -- Searchable Querical Data Networks -- Semantic Overlay Clusters within Super-Peer Networks -- Structuring Peer-to-Peer Networks Using Interest-Based Communities -- Semantics and Data Integration -- A Robust Logical and Computational Characterisation of Peer-to-Peer Database Systems -- Semantic Data Integration in P2P Systems -- Defining Peer-to-Peer Data Integration Using Both as View Rules -- Coordinating Peer Databases Using ECA Rules -- Data Streams and Publish/Subscribe -- An Adaptive and Scalable Middleware for Distributed Indexing of Data Streams -- Building Content-Based Publish/Subscribe Systems with Distributed Hash Tables -- Data Structures and Query Processing -- AmbientDB: Relational Query Processing in a P2P Network -- Towards a Unifying Framework for Complex Query Processing over Structured Peer-to-Peer Data Networks -- Distributed Queries and Query Optimization in Schema-Based P2P-Systems -- PePeR: A Distributed Range Addressing Space for Peer-to-Peer Systems -- Efficient Search in Structured Peer-to-Peer Systems: Binary v.s. K-Ary Unbalanced Tree Structures -- Content-Based Overlay Networks for XML Peers Based on Multi-level Bloom Filters.

Peer-to-peer(P2P)computingiscurrentlyattractingenormousmediaattention, spurred by the popularity of ?le sharing systems such as Napster, Gnutella and Morpheus. In P2P systems a very large number of autonomous computing nodes (the peers) pool together their resources and rely on each other for data and services. The wealth of business opportunities promised by P2P networks has gene- ted much industrial interest recently, and has resulted in the creation of various industrial projects, startup companies, and special interest groups. Researchers from distributed computing, networks, agents and databases have also become excited about the P2P vision, and papers tackling open problems in this area have started appearing in high-quality conferences and workshops. Much of the recent research on P2P systems seems to be carried out by - search groups with a primary interest in distributed computation and networks. This workshop concentrated on the impact that current database research can have on P2P computing and vice versa. Although researchers in distributed data structures and databases have been working on related issues for a long time, the developed techniques are simply not adequate for the new paradigm.