A DHT-based infrastructure for ad-hoc integration and querying of semantic data

A crucial prerequisite for the deployment and success of Peer-to-Peer data management applications is the availability of metadata in a way that makes it easy to access and combine data from different sources and domains. In this paper, we argue for a unified and distributed infrastructure providing a repository for semantic data by offering location transparency and advanced query services. After discussing the challenges of such an approach, we present our solution which applies extended SPARQL-like query features for dealing with large and possibly heterogeneous data sets. We focus on the integration into efficient distributed query processing and evaluate our approach in a series of experiments.