On Equality-Generating Dependencies in Ontology Querying - Preliminary Report

In ontology-based data access, data are queried through an ontology that offers a representation of the domain of interest. In this context, correct answers are those entailed by the logical theory constituted by the data and the ontology. Traditional database constraints like tuple-generating dependencies (TGDs) and equality-generating de- pendencies (EGDs) are a useful tool for ontology specification. However, their interaction usually leads to intractability or undecidability of query answering; separability is the notion that captures the lack of interaction between TGDs and EGDs. In this paper we exhibit a novel and general sufficient condition for separability, in the case where the ontology is expressed with inclusion dependencies (a subclass of TGDs) and EGDs.

[1]  Andrea Calì,et al.  Query Answering under Non-guarded Rules in Datalog+/- , 2010, RR.

[2]  Diego Calvanese,et al.  Tractable Reasoning and Efficient Query Answering in Description Logics: The DL-Lite Family , 2007, Journal of Automated Reasoning.

[3]  Andrea Calì,et al.  On the decidability and complexity of query answering over inconsistent and incomplete databases , 2003, PODS.

[4]  David Maier,et al.  Testing implications of data dependencies , 1979, SIGMOD '79.

[5]  Andrea Calì,et al.  Advanced processing for ontological queries , 2010, Proc. VLDB Endow..

[6]  Andrea Calì,et al.  Query Answering under Expressive Entity-Relationship Schemata , 2010, ER.

[7]  Thomas Eiter,et al.  \mathbbFDNC: Decidable Non-monotonic Disjunctive Logic Programs with Function Symbols , 2007, LPAR.

[8]  Andrea Calì,et al.  Accessing Data Integration Systems through Conceptual Schemas , 2001, ER.

[9]  Michael Kifer,et al.  Logical foundations of object-oriented and frame-based languages , 1995, JACM.

[10]  Ronald Fagin,et al.  Data exchange: semantics and query answering , 2003, Theor. Comput. Sci..

[11]  Diego Calvanese,et al.  Linking Data to Ontologies , 2008, J. Data Semant..

[12]  Andrea Calì,et al.  Taming the Infinite Chase: Query Answering under Expressive Relational Constraints , 2008, Description Logics.

[13]  Andrea Calì,et al.  Containment of conjunctive object meta-queries , 2006, VLDB.

[14]  Andrea Calì,et al.  Tractable Query Answering over Conceptual Schemata , 2009, ER.

[15]  John C. Mitchell.  The Implication Problem for Functional and Inclusion Dependencies , 1984, Inf. Control..

[16]  Alin Deutsch,et al.  The chase revisited , 2008, PODS.

[17]  David S. Johnson,et al.  Testing containment of conjunctive queries under functional and inclusion dependencies , 1982, J. Comput. Syst. Sci..

[18]  Andrea Calì,et al.  A general datalog-based framework for tractable query answering over ontologies , 2009, SEBD.