Abstract. Many approaches for RDF stores exist, most of them using very straight-forward techniques to store triples in or mapping RDF Schema classes to database tables. In this paper we propose an RDF store that uses a natural mapping of RDF resources to database tables that does not rely on RDF Schema, but constructs a schema based on the occurring signatures, where a signature is the set of properties used on a resource. This technique can therefore be used for arbitrary RDF data, i.e., RDF Schema or any other schema/ontology language on top of RDF is not required. Our approach can be used for both in-memory and on-disk relational database-based RDF store implementations. A first prototype has been implemented and already shows a significant performance increase compared to other freely available (inmemory) RDF stores.