74816 20180830104418.0 sideral 106966 ART-1998-106966 eng Goñi, Alfredo An Ontology Connected to Several Data Repositories: Query Processing Steps 1998 Access copy available to the general public Unrestricted The 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. info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Illarramendi, Arantza (orcid)0000-0002-7462-0080 Mena, Eduardo Universidad de Zaragoza Blanco, José Miguel 5007 570 Universidad de Zaragoza Dpto. Informát.Ingenie.Sistms. Área Lenguajes y Sistemas Inf. 3, 1 (1998), [8 pp.] J. comput. inf. Journal of computing and information 1201-8511 http://sid.cps.unizar.es/PUBLICATIONS/POSTSCRIPTS/icci98.ps.gz Texto completo de la revista 109381 http://zaguan.unizar.es/record/74816/files/texto_completo.pdf Postprint 114128 http://zaguan.unizar.es/record/74816/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:74816 articulos driver 2018-08-30-10:26:24 ARTICLE