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Querying several conflicting databases

Cholvy, Laurence and Garion, Christophe Querying several conflicting databases. (2004) Journal of applied non-classical logics, 1 (3). 295-327. ISSN 1166-3081

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Official URL: http://dx.doi.org/10.3166/jancl.14.295-327


This paper addresses the problem of querying several databases considered as a whole. Assuming that the different databases share a common data description language, the problem that arises is to consistently answer queries even if the database contents are contradictory. The main contribution of this paper is the specification of a query-evaluator for answering closed and open general queries addressed to several databases and for providing explanations about the results. For doing so, we first specify a query-evaluator, in logic, which assumes that the databases are propositional ones and do not contain disjunctions. Then we extend it to first-order databases defined by an extensional part (sets of positive or negative facts) and an intentional part (sets of first order clauses). We also show that the query-evaluator corresponds to a majority merging of the databases.

Item Type:Article
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Université de Toulouse > Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE)
French research institutions > Office National d'Etudes et Recherches Aérospatiales - ONERA (FRANCE)
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Deposited On:30 Jul 2008 14:03

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