000074816 001__ 74816 000074816 005__ 20180830104418.0 000074816 0248_ $$2sideral$$a106966 000074816 037__ $$aART-1998-106966 000074816 041__ $$aeng 000074816 100__ $$aGoñi, Alfredo 000074816 245__ $$aAn Ontology Connected to Several Data Repositories: Query Processing Steps 000074816 260__ $$c1998 000074816 5060_ $$aAccess copy available to the general public$$fUnrestricted 000074816 5203_ $$aThe great expansion of communication networks has made avail- able to users a huge number of heterogeneous and autonomous data repositories that present different structures/organizations, query languages and data semantics. In that context it is clear that new information retrieval techniques with a strategy that focuses on in- formation content and semantics are needed. We propose to use domain specific Ontologies to capture the information content of such repositories whenever available. We describe such Ontolo- gies using a system based on Description Logics. In this paper we present all the stages of the processing of a query formulated over an Ontology when the answer must be found in the underly- ing data repositories. Those stages make up a subpart of the global query processing strategy defined for a set of loosely-coupled On- tologies. We show first how the query is transformed into a seman- tically equivalent one and how inconsistent queries are detected. Then, we explain the test to verify if the query can be answered from the cache memory. Next, we present a set of heuristics used during the query decomposition process. Later on, we show how to optimize plans associated to subqueries that access the underlying data repositories and finally we illustrate how the answers retrieved from the repositories are correlated in order to generate the query answer. 000074816 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/ 000074816 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000074816 700__ $$aIllarramendi, Arantza 000074816 700__ $$0(orcid)0000-0002-7462-0080$$aMena, Eduardo$$uUniversidad de Zaragoza 000074816 700__ $$aBlanco, José Miguel 000074816 7102_ $$15007$$2570$$aUniversidad de Zaragoza$$bDpto. Informát.Ingenie.Sistms.$$cÁrea Lenguajes y Sistemas Inf. 000074816 773__ $$g3, 1 (1998), [8 pp.]$$pJ. comput. inf.$$tJournal of computing and information$$x1201-8511 000074816 85641 $$uhttp://sid.cps.unizar.es/PUBLICATIONS/POSTSCRIPTS/icci98.ps.gz$$zTexto completo de la revista 000074816 8564_ $$s109381$$uhttps://zaguan.unizar.es/record/74816/files/texto_completo.pdf$$yPostprint 000074816 8564_ $$s114128$$uhttps://zaguan.unizar.es/record/74816/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000074816 909CO $$ooai:zaguan.unizar.es:74816$$particulos$$pdriver 000074816 951__ $$a2018-08-30-10:26:24 000074816 980__ $$aARTICLE