Requirements from new types of applications call for new database system solutions. Computational science applications performing distributed computations on Grid networks with requirements for efficient storage and query solutions are now emerging. For this purpose we have developed DASCOSADB, a P2P-based distributed database system, which in addition to providing location-transparent storage and querying, also includes novel features like efficient partial restart of queries and redistribution of query operators in the context of failure, dynamic refragmentation and allocation, and distributed semantic caching. In this demo, the novel features will be demonstrated, combined with a more general description of the architecture and demonstration of the distributed query processing capabilities.