15.30, room 445, PCRI
We introduce the database fragment of RDF, which extends the popular Description Logic fragment, in particular with support for incomplete information. We then provide novel sound and complete saturation- and reformulation-based techniques for answering the Basic Graph Pattern queries of SPARQL in this fragment. Notably, we extend the state of the art on pushing RDF query processing within robust / efficient relational database management systems. Finally, we experimentally compare our query answering techniques using well-established datasets.