Conjunctive query answering with OWL 2 QL

Abstract

We present a novel rewriting technique for conjunctive
\nquery answering over OWL2QL ontologies. In general,
\nthe obtained rewritings are not necessarily correct
\nand can be of exponential size in the length of the
\nquery. We argue, however, that in most, if not all, practical
\ncases the rewritings are correct and of polynomial
\nsize. Moreover, we prove some sufficient conditions,
\nimposed on queries and ontologies, that guarantee correctness
\nand succinctness. We also support our claim by
\nexperimental results.