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Answering SPARQL Queries over Databases under OWL 2 QL Entailment Regime
[chapter]
2014
Lecture Notes in Computer Science
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We present an extension of the ontology-based data access platform Ontop that supports answering SPARQL queries under the OWL 2 QL direct semantics entailment regime for data instances stored in relational ...
OWL 2 QL graph patterns are constructed from OWL 2 QL BGPs using the SPARQL operators. Finally, an OWL 2 QL query is a pair (P, V ), where P is an OWL 2 QL graph pattern and V ⊆ var(P ). ...
SPARQL queries under the OWL 2 QL entailment regime with data instances stored in a database. ...
doi:10.1007/978-3-319-11964-9_35
fatcat:qxyznp6o3baldm7flrw4gjouki
Towards Reconciling SPARQL and Certain Answers (Extended Abstract)
2015
Alberto Mendelzon Workshop on Foundations of Data Management
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by the presence of OWL 2 QL entailment under the proposed semantics. ...
However, the semantics of query answering under SPARQL entailment regimes is defined in a more naive and much less expressive way than the certain answer semantics usually adopted in database and DL literature ...
In [2] , the authors describe a rewriting of SPARQL query answering under OWL 2 QL into Datalog ± . ...
dblp:conf/amw/AhmetajFPSS15
fatcat:m7pltyinqrhh5ok6wuvmafu2wa
Querying OWL 2 QL ontologies under the SPARQL Metamodeling Semantics Entailment Regime
2017
Sistemi Evoluti per Basi di Dati
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Indeed, SPARQL queries over OWL 2 QL, under the so-called Direct Semantics Entailment Regime, may comprise any assertion expressible in the language, i.e., both ABox atoms and TBox atoms, including inequalities ...
OWL 2 QL is the profile of OWL 2 targeted to Ontology-Based Data Access (OBDA) scenarios, where large amount of data are to be accessed, and thus answering conjunctive queries over data is the main task ...
The most typical SPARQL Entailment Regime for OWL 2 QL ontologies is the Direct Semantics Entalment Regime (DSER). ...
dblp:conf/sebd/CimaGLP17
fatcat:paygaudv35eojd6ela5mavykxa
On the SPARQL Direct Semantics Entailment Regime for OWL 2 QL
2016
International Workshop on Description Logics
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Thus, in this paper, we investigate query answering over OWL 2 QL under DSER. ...
Finally, we investigate query answering under a new SPARQL entailment regime, called Direct Semantics Answering Regime (DSAR), obtained by modifying DSER in such a way that existentially quantified variables ...
Acknowledgements We gratefully acknowledge support by the MIUR under the SIR project MODEUS (RBSI14TQHQ), and by Regione Lazio under the project MAGISTER. ...
dblp:conf/dlog/Poggi16
fatcat:xi7qhubxo5eg3hiy7ww7unkj6e
Ontology-Based Integration of Cross-Linked Datasets
[chapter]
2015
Lecture Notes in Computer Science
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In this paper we tackle the problem of answering SPARQL queries over virtually integrated databases. ...
This is partly because the OWL built-in owl:sameAs property, the most natural representation of links between data sets, is not included in OWL 2 QL, the de facto ontology language for OBDA. ...
SPARQL Entailment Regime We present now the standard W3C semantics for SPARQL queries over OWL 2 ontologies under different entailment regimes. ...
doi:10.1007/978-3-319-25007-6_12
fatcat:rkm7obtudvgrtfrq5r6pynfuuq
Towards Reconciling SPARQL and Certain Answers
2015
Proceedings of the 24th International Conference on World Wide Web - WWW '15
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For OWL 2 QL entailment, we present algorithms for the evaluation of an interesting fragment of SPARQL (the so-called well-designed SPARQL). ...
However, the semantics of query answering under SPARQL entailment regimes is defined in a more naive and much less expressive way than the certain answer semantics usually adopted in DLs. ...
In [1] , the authors describe a rewriting of SPARQL query answering under OWL 2 QL into Datalog ± . ...
doi:10.1145/2736277.2741636
dblp:conf/www/AhmetajFPSS15
fatcat:3f2254oh7jhqdf7lptvsjefyae
Efficient Ontology-Based Data Integration with Canonical IRIs
[chapter]
2018
Lecture Notes in Computer Science
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Formally, we present our approach as a new SPARQL entailment regime and compare it with the sameAs approach. ...
In ontologybased data integration (OBDI) an ontology provides a coherent view of multiple databases, and SPARQL queries over the ontology are rewritten into (federated) SQL queries over the underlying ...
This research is supported by the project OBATS, funded by Free University of Bozen-Bolzano, by the Euregio IPN12 KAOS, funded by the "European Region Tyrol-South Tyrol-Trentino" (EGTC) under the first ...
doi:10.1007/978-3-319-93417-4_45
fatcat:wounev4lmvbyvfk5xhckcaeqfe
Advancing the Enterprise-class OWL Inference Engine in Oracle Database
2012
International Workshop on OWL Reasoner Evaluation
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In this paper, we discuss our recent implementation and optimization techniques for query-rewrite based OWL 2 QL reasoning, named graph-based inference (local inference), and integration with external ...
Having a solid OWL reasoning engine inside a relational database system like Oracle is significant because 1) many relational techniques, including query optimization, compression, partitioning, and parallel ...
We thereby adopt, in addition to ER, another entailment regime for Abox queries to OWL 2 QL ontologies, namely OWL 2 QL Entailment Regime (QLER). ...
dblp:conf/ore/WuREKK12
fatcat:isinrkr7zzekdg7yc2ji4fzgl4
Ontop: Answering SPARQL queries over relational databases
2016
Semantic Web Journal
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exploiting all elements of the OBDA architecture, its compliance to all relevant W3C recommendations (including SPARQL queries, R2RML mappings, and OWL 2 QL and RDFS ontologies), and its support for all ...
major relational databases. ...
This article is supported by the EU under the large-scale integrating project (IP) Optique (Scalable End-user Access to Big Data), grant agreement n. FP7-318338. ...
doi:10.3233/sw-160217
fatcat:mjwgfop5tvfvpf3rr6flpfvmwq
FRaQuE: A Framework for Rapid Query Processing Evaluation
2013
International Workshop on OWL Reasoner Evaluation
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In this paper we present FRaQuE (Framework for Rapid Query Processing Evaluation). ...
The main purpose of FRaQuE is to offer to a non-expert user a "push-button" solution aimed to help her to evaluate query processors for Ontology Based Data Access, focusing only on input and output data ...
Under the second regime, we focus on the notion of entailment for the semantics of OWL 2 QL. ...
dblp:conf/ore/BourguetP13
fatcat:bymtx7fjmfbsvmrv2vt7oy4w7m
A Datalog-Based Language for Querying RDF Graphs
2016
Alberto Mendelzon Workshop on Foundations of Data Management
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To the best of our knowledge, the only language that supports the above features, focussing on the profile OWL 2 QL of OWL 2, while its query evaluation problem is tractable in data complexity, is the ...
However, there are still useful queries that cannot be expressed in SPARQL 1.1, due to the lack of general recursion [14] . ...
Arenas is funded by the Millenium Nucleus Center for Semantic Web Research under grant NC120004. ...
dblp:conf/amw/ArenasGP16
fatcat:oiwppq73hbfxzj3rnxkpx4py2m
Schema-Agnostic Query Rewriting in SPARQL 1.1
[chapter]
2014
Lecture Notes in Computer Science
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SPARQL 1.1 supports the use of ontologies to enrich query results with logical entailments, and OWL 2 provides a dedicated fragment OWL QL for this purpose. ...
This allows us to query RDF data under OWL QL entailment without extracting or preprocessing OWL axioms. ...
The answers of a conjunctive query q over an OWL QL ontology G are exactly the answers of the SPARQL 1.1 query Rewrite(q) over G under simple entailment. ...
doi:10.1007/978-3-319-11964-9_37
fatcat:ytt3lolq75bqfgmyhaijhiarzm
The Ontop Framework for Ontology Based Data Access
[chapter]
2014
Communications in Computer and Information Science
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The main functionality of OBDA systems is query answering. ...
Usually, the conceptual layer is expressed in the form of an RDF(S) [10] or OWL [15] ontology, and the data is stored in relational databases. ...
This paper is supported by the EU under the large-scale integrating project (IP) Optique (Scalable End-user Access to Big Data), grant agreement n. FP7-318338. ...
doi:10.1007/978-3-662-45495-4_6
fatcat:77pqwm6dznf5nexppacg2oxfxa
Optimizing Query Answering over OWL Ontologies
[chapter]
2011
Lecture Notes in Computer Science
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That is why, when the schema of an ontology is written in a highly expressive language like OWL 2 DL, currently used query answering systems do not find all answers to queries posed over the ontology, ...
Query answering is a key reasoning task for many ontology based applications in the Semantic Web. Unfortunately for OWL, the worst case complexity of query answering is very high. ...
OWL entailment relation (the OWL entailment regime of SPARQL [5] ). ...
doi:10.1007/978-3-642-21064-8_45
fatcat:kumdiz4vhfahvd7mqyt7yhlivq
Answering Queries over OWL Ontologies with SPARQL
2011
W3C Web Ontology Language (OWL) Experiences and Directions Workshop (OWLED)
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The SPARQL query language is currently being extended by W3C with so-called entailment regimes, which define how queries are evaluated under more expressive semantics than SPARQL's standard simple entailment ...
We describe a sound and complete algorithm for the OWL Direct Semantics entailment regime. ...
SPARQL-OWL Query Answering We first give a brief introduction to the SPARQL-OWL entailment regime and then describe an algorithm that finds answers to queries under this regime. ...
dblp:conf/owled/KolliaGH11
fatcat:h5rjf4oua5aybje3agyxfs2ccu
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