| T. Venetis, G. Stoilos, G. Stamou |
| Incremental Query Rewriting for OWL 2 QL |
| 25th International Workshop on Description Logics (DL2012) |
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ABSTRACT
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| Query rewriting over lightweight ontologies, like DL-Lite ontologies, is a prominent approach for ontology-based data access. Given a query q and a DL-Lite ontology T the standard approach is to apply a set of equivalence preserving transformations, usually in a relative brute-force manner, in order to produce a so-called perfect-reformulation rewriting which captures all the possible answers of q,T over any input data. In the current paper we present a new algorithm to query rewriting that is based on a novel incremental strategy. More precisely, given a query $q$ the algorithm computes `partial-rewritings' for each of the atoms of the query and then iteratively combines them in order to compute a rewriting for q,T. In effect this also shows that the process of rewriting (at-least for DL-Lite) can be largely performed in parallel by `decomposing' q into sub-parts. In order to further improve the efficiency of the algorithm we additionally present a set of optimizations. Finally, we have implemented all algorithms and performed an extensive experimental evaluation showing that in general our algorithm is faster than all previously known ones.
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| 07 June , 2012 |
| T. Venetis, G. Stoilos, G. Stamou, "Incremental Query Rewriting for OWL 2 QL", 25th International Workshop on Description Logics (DL2012) |
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