Computing FO-Rewritings in $$\mathcal{EL}$$ in Practice: From Atomic to Conjunctive Queries [chapter]

Peter Hansen, Carsten Lutz
2017 Lecture Notes in Computer Science  
A prominent approach to implementing ontology-mediated queries (OMQs) is to rewrite into a first-order query, which is then executed using a conventional SQL database system. We consider the case where the ontology is formulated in the description logic EL and the actual query is a conjunctive query and show that rewritings of such OMQs can be efficiently computed in practice, in a sound and complete way. Our approach combines a reduction with a decomposed backwards chaining algorithm for OMQs
more » ... hat are based on the simpler atomic queries, also illuminating the relationship between first-order rewritings of OMQs based on conjunctive and on atomic queries. Experiments with real-world ontologies show promising results.
doi:10.1007/978-3-319-68288-4_21 fatcat:nrynnalwdbdthnbjbf5i74c4pi