Results 1 to 10 of about 50 (50)
Proceedings of the 18th international conference on World wide web, 2009 C-SPARQL is an extension of SPARQL to support continuous queries, registered and continuously executed over RDF data streams, considering windows of such streams. Supporting streams in RDF format guarantees interoperability and opens up important applications, in which reasoners can deal with knowledge that evolves over time.
BARBIERI, DAVIDE FRANCESCO +4 more
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Semantics and Complexity of SPARQL [PDF]
ACM Transactions on Database Systems, 2006 SPARQL is the standard language for querying RDF data. In this article, we address systematically the formal study of the database aspects of SPARQL, concentrating in its graph pattern matching facility. We provide a compositional semantics for the core part of SPARQL, and study the complexity of the evaluation of several fragments of the language ...
Perez, Jorge +2 more
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Semantic Web, 2015 The need for recursive queries in the Semantic Web setting is becoming more and more apparent with the emergence of datasets where different pieces of information are connected by complicated patterns. This was acknowledged by the W3C committee by the inclusion of property paths in the SPARQL standard.
Reutter, Juan L. +2 more
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Efficient SPARQL Autocompletion via SPARQL
, 2021 We show how to achieve fast autocompletion for SPARQL queries on very large knowledge bases. At any position in the body of a SPARQL query, the autocompletion suggests matching subjects, predicates, or objects. The suggestions are context-sensitive in the sense that they lead to a non-empty result and are ranked by their relevance to the part of the ...
Bast, Hannah +4 more
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SPARQLES: Monitoring public SPARQL endpoints
Semantic Web, 2017 Fujitsu Laboratories Limited CONICYT/FONDECYT Project 3130617 FONDECYT Project 11140900 DGIP Project 116.24.1 Millennium Nucleus Center for Semantic Web Research ...
Vandenbussche, Pierre Yves +4 more
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On the Formulation of Performant SPARQL Queries [PDF]
SSRN Electronic Journal, 2015 The combination of the flexibility of RDF and the expressiveness of SPARQL provides a powerful mechanism to model, integrate and query data. However, these properties also mean that it is nontrivial to write performant SPARQL queries. Indeed, it is quite easy to create queries that tax even the most optimised triple stores.
Loizou +3 more
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On the Marriage of SPARQL and Keywords [PDF]
, 2015 Although SPARQL has been the predominant query language over RDF graphs, some query intentions cannot be well captured by only using SPARQL syntax. On the other hand, the keyword search enjoys widespread usage because of its intuitive way of specifying information needs but suffers from the problem of low precision.
Lei Zou, Dongyan Zhao, Peng Peng
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Provenance for SPARQL Queries [PDF]
, 2012 Determining trust of data available in the Semantic Web is fundamental for applications and users, in particular for linked open data obtained from SPARQL endpoints. There exist several proposals in the literature to annotate SPARQL query results with values from abstract models, adapting the seminal works on provenance for annotated relational ...
Carlos Viegas Damásio +2 more
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Flexible Querying for SPARQL [PDF]
, 2014 Flexible querying techniques can be used to enhance users' access to heterogeneous data sets, such as Linked Open Data. This paper extends SPARQL 1.1 with approximation and relaxation operators that can be applied to regular expressions for querying property paths in order to find more answers than would be returned by the exact form of a user query ...
Alexandra Poulovassilis +4 more
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SPARQLing constraints for RDF [PDF]
Proceedings of the 11th international conference on Extending database technology Advances in database technology - EDBT '08, 2008 The goal of the Semantic Web is to support semantic interoperability between applications exchanging data on the web. The idea heavily relies on data being made available in machine readable format, using semantic markup languages. In this regard, the W3C has standardized RDF as the basic markup language for the Semantic Web.
Georg Lausen +2 more
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