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The DL-Lite Family and Relations
This article carries out a thorough and systematic investigation of inference in extensions of the original DL-Lite logics along five axes, by adding the Boolean connectives and number restrictions to concept constructs and adopting or dropping the unique name assumption. Expand
Ontop: Answering SPARQL queries over relational databases
We present Ontop, an open-source Ontology-Based Data Access (OBDA) system that allows for querying relational data sources through a conceptual representation of the domain of interest, provided inExpand
Ontology-Based Data Access: Ontop of Databases
The architecture and technologies underpinning the OBDA system Ontop are presented and it is demonstrated that, for standard ontologies, queries and data stored in relational databases, Ontop is fast, efficient and produces SQL rewritings of high quality. Expand
The Combined Approach to Query Answering in DL-Lite
This paper proposes an alternative approach to implementing ontology-based data access in DL-Lite by allowing rewriting of both the query and the data and demonstrates that query execution in the proposed approach is often more efficient than in existing approaches, especially for large ontologies. Expand
The Combined Approach to Ontology-Based Data Access
The combined approach is described, which incorporates the information given by the ontology into the data and employs query rewriting to eliminate spurious answers in ontology-based data access. Expand
Reasoning over Extended ER Models
The lower complexity bound results are proved by direct reductions, while the upper bounds follow from the correspondences with expressive variants of the description logic DL-Lite, which are established in this paper. Expand
Temporalising Tractable Description Logics
It is known that for temporal languages, such as first-order LTL, reasoning about constant (time-independent) relations is almost always undecidable. This applies to temporal description logics asExpand
Ontology-Based Data Access: A Survey
We present the framework of ontology-based data access, a semantic paradigm for providing a convenient and user-friendly access to data repositories, which has been actively developed and studied inExpand
Temporal Description Logic for Ontology-Based Data Access
A temporal description logic, TQL, is designed that extends the standard ontology language OWL 2 QL, provides basic means for temporal conceptual modelling and ensures first-order rewritability of conjunctive queries for suitably defined data instances with validity time. Expand
Can You Tell the Difference Between DL-Lite Ontologies?
It is shown that checking difference and entailment can be automated by means of encoding into QBF satisfiability and using off-the-shelf QBF solvers, and the relationship between the notion of forgetting and the authors' notions of difference between ontologies is explored. Expand