Dependencies: Making Ontology Based Data Access Work In Practice

Mariano Rodriguez-Muro and Diego Calvanese

Proc. of the 5th Alberto Mendelzon Int. Workshop on Foundations of Data Management (AMW 2011). Volume 749 of CEUR Workshop Proceedings, http://ceur-ws.org/. 2011.

Query answering in Ontology Based Data Access (OBDA) exploits the knowledge of an ontology's TBox to deal with incompleteness of the ABox (or data source). Current query-answering techniques with DL-Lite require exponential size query reformulations, or expensive data pre-processing, and hence may not be suitable for data intensive scenarios. Also these techniques present severe redundancy issues when dealing with ABoxes that are already (partially) complete. It has been shown that addressing redundancy is not only required for tractable implementations of decision procedures, but may also allow for sizable improvements in execution times. Considering the previous observations, in this paper we present two complementary sets of results that aim at improving query answering performance in OBDA systems. First, we show that we can characterize completeness of an ABox by means of dependencies, and that we can use these to optimize DL-Lite TBoxes. Second, we show that in OBDA systems we can create ABox repositories that appear to be complete w.r.t. a significant portion of any DL-Lite TBox. The combination of these results allows us to design OBDA systems in which redundancy is minimal, the exponential aspect of query answering is notably reduced and that can be implemented efficiently using existing RDBMSs.


@inproceedings{AMW-2011,
   title = "Dependencies:  Making Ontology Based Data Access Work In
Practice",
   year = "2011",
   author = "Mariano Rodriguez-Muro and Diego Calvanese",
   booktitle = "Proc. of the 5th Alberto Mendelzon Int. Workshop on
Foundations of Data Management (AMW 2011)",
   volume = "749",
   series = "CEUR Workshop Proceedings, http://ceur-ws.org/",
}
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