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nSPARQL: A navigational language for RDF

Jorge Pérez, Marcelo Arenas, Claudio Gutierrez
2010 Journal of Web Semantics  
In particular, we have argued in a previous paper that nested regular expressions are appropriate to navigate RDF data, and we have proposed the nSPARQL query language for RDF, that uses nested regular  ...  Navigational features have been largely recognized as fundamental for graph database query languages.  ...  We are grateful to the anonymous referees for their helpful comments.  ... 
doi:10.1016/j.websem.2010.01.002 fatcat:6vdrbmekhzcshkuo3endszcjwa

nSPARQL: A Navigational Language for RDF [chapter]

Jorge Pérez, Marcelo Arenas, Claudio Gutierrez
2008 Lecture Notes in Computer Science  
In particular, we have argued in a previous paper that nested regular expressions are appropriate to navigate RDF data, and we have proposed the nSPARQL query language for RDF, that uses nested regular  ...  Navigational features have been largely recognized as fundamental for graph database query languages.  ...  We are grateful to the anonymous referees for their helpful comments.  ... 
doi:10.1007/978-3-540-88564-1_5 fatcat:sdvo67iyhvcvpcoeiesedfntfm

Context-Free Path Queries on RDF Graphs [article]

Xiaowang Zhang, Zhiyong Feng, Xin Wang, Guozheng Rao, Wenrui Wu
2016 arXiv   pre-print
Most of the navigational query languages used in the RDF community, e.g. property paths in W3C SPARQL 1.1 and nested regular expressions in nSPARQL, are based on the regular expressions.  ...  Despite the increasing expressivity, we show that cfSPARQL still enjoys a low computational complexity and can be evaluated efficiently.  ...  Acknowledgments The authors thank Jelle Hellings and Guohui Xiao for their helpful and constructive comments.  ... 
arXiv:1506.00743v3 fatcat:jor6wnudqjcpfom5zitpcppbey

Constrained regular expressions for answering RDF-path queries modulo RDFS

Faisal Alkhateeb, Jerome Euzenat
2014 International Journal of Web Information Systems  
The standard SPARQL query language is currently defined for querying RDF graphs without RDFS semantics. Several extensions of SPARQL to RDFS semantics have been proposed.  ...  We show that both languages have the same complexity through cpSPARQL, being a proper extension of SPARQL graph patterns, is more expressive than nSPARQL.  ...  Figure 3 shows the position of the various languages. nSPARQL and cpSPARQL are good navigational languages for RDF(S).  ... 
doi:10.1108/ijwis-05-2013-0013 fatcat:qudamqe2wrdj7bomftwmh7z3ta

Answering SPARQL queries modulo RDF Schema with paths [article]

Faisal Alkhateeb, Jérôme Euzenat (INRIA Grenoble Rhône-Alpes / LIG Laboratoire d'Informatique de Grenoble)
2013 arXiv   pre-print
SPARQL is the standard query language for RDF graphs.  ...  In particular, we show that the PSPARQL query language, a strict extension of SPARQL offering transitive closure, allows for answering SPARQL queries modulo RDFS graphs with the same complexity as SPARQL  ...  This research report sums up our knowledge about the various ways to query RDF graph modulo RDFS, providing improvements on all the existing proposals. Part of it will be published as [6].  ... 
arXiv:1311.3879v1 fatcat:hqdtvcko7ng5vhc3t4i6k5xtam

Path discovery by Querying the federation of Relational Database and RDF Graph [article]

Xiaowang Zhang and Jiahui Zhang and Muhammad Qasim Yasin and Wenrui Wu and Zhiyong Feng
2016 arXiv   pre-print
In this paper, we present a federated path querying language as an extension of regular path querying language for supporting RDF graph integration with relational database.  ...  Most of the path querying languages used by the RDF community, like property paths in W3C SPARQL 1.1 and nested regular expressions in nSPARQL are based on the regular expressions.  ...  Many existing navigational query languages for graphs are based on binary relational algebra such as XPath (a standard navigational query language for trees [26] ) or regular expressions such as RPQ (  ... 
arXiv:1610.07707v1 fatcat:nrjaufmkpbamjlnlcyznh72tei

Towards Enriching CQELS with Complex Event Processing and Path Navigation

Minh Dao-Tran, Danh Le Phuoc
2015 Deutsche Jahrestagung für Künstliche Intelligenz  
Among these, CQELS has been developed with a native and adaptive approach, which gives it a performance advantage over other engines.  ...  We propose in this paper an extension of the CQELS query language and semantics towards enriching CQELS with these attractive functionalities.  ...  Preliminaries This section briefly reviews the basic building blocks of this work, namely RDF, SPARQL, RDF stream processing, the navigation language nSPARQL, and CEP.  ... 
dblp:conf/ki/Dao-TranP15 fatcat:iys5y6qbpzhzxkrigjyu2v66jq

The Perfect Match: RPL and RDF Rule Languages [chapter]

François Bry, Tim Furche, Benedikt Linse
2009 Lecture Notes in Computer Science  
Path query languages have been previously shown to complement RDF rule languages in a natural way and have been used as a means to implement the RDFS derivation rules.  ...  We give a compositional semantics for RP L and show that it can be evaluated efficiently, while several possible extensions of it cannot.  ...  Graph traversal operators play a crucial role in rule and query languages for semi-structured data and for RDF rule languages in particular.  ... 
doi:10.1007/978-3-642-05082-4_16 fatcat:ippqvywmbnay5k5ew65q4ci2cq

Foundations of RDF Databases [chapter]

Marcelo Arenas, Claudio Gutierrez, Jorge Pérez
2009 Lecture Notes in Computer Science  
In particular, we present a recently proposed extension of SPARQL with navigational capabilities, and show that this language is expressive enough to deal with the semantics of the RDFS vocabulary.  ...  We provide an algebraic syntax and a compositional semantics for this language, study the complexity of the evaluation problem for different fragments of SPARQL, and consider the problem of optimizing  ...  blank node B by a fresh variable ?  ... 
doi:10.1007/978-3-642-03754-2_4 fatcat:m3z7aqgcirak5jgrebyr4qmtsa

Querying semantic web data with SPARQL

Marcelo Arenas, Jorge Pérez
2011 Proceedings of the 30th symposium on Principles of database systems of data - PODS '11  
RDF is the data model for Semantic Web data, and SPARQL is the standard query language for this data model.  ...  of efficient mechanisms for implementing this query language.  ...  Navigating RDF graphs: As with any data model, a natural question is what are the desired features for an RDF query language.  ... 
doi:10.1145/1989284.1989312 dblp:conf/pods/ArenasP11 fatcat:yfcudyqbb5fglet26ugkgcg4v4

Extended Property Paths: Writing More SPARQL Queries in a Succinct Way

Valeria Fionda, Giuseppe Pirrò, Mariano Consens
We introduce Extended Property Paths (EPPs), a significant enhancement of SPARQL property paths. EPPs allow to capture in a succinct way a larger class of navigational queries than property paths.  ...  The first is based on an algorithm implemented in a custom query processor.  ...  We have provided an algorithm for their evaluation and also a translation procedure into SPARQL.  ... 
doi:10.1609/aaai.v29i1.9188 fatcat:xqdzbunuhjbfrmfiznudrbyo6i

Modeling Concept Evolution: A Historical Perspective [chapter]

Flavio Rizzolo, Yannis Velegrakis, John Mylopoulos, Siarhei Bykau
2009 Lecture Notes in Computer Science  
Our proposal extends an RDF-like model with temporal features and evolution operators. Then we provide a query language that exploits these extensions and supports historical queries.  ...  In this work, we present a formal framework for modeling, querying and managing such evolution.  ...  This language is analogous to nSPARQL [17] , a language that extends SPARQL with navigational capabilities based on nested regular expressions. nSPARQL uses four different axes, namely self , next, edge  ... 
doi:10.1007/978-3-642-04840-1_25 fatcat:qktfv4zqtnbg5m6fej5fds6wo4

A RPL through RDF: Expressive Navigation in RDF Graphs [chapter]

Harald Zauner, Benedikt Linse, Tim Furche, François Bry
2010 Lecture Notes in Computer Science  
guage for navigating in RDF graphs proposed to date that can still be evaluated with polynomial combined complexity. RPL is a lean language well-suited for integration into RDF rule languages.  ...  In this demonstration, we show how to solve this and similar analysis tasks with a novel RDF path language, called RPL.  ... 
doi:10.1007/978-3-642-15918-3_25 fatcat:jregzsalazfotflguyf22qqeai

On the Power of SPARQL in Expressing Navigational Queries

Xiaowang Zhang, Jan Van den Bussche
2014 Computer journal  
The calculus of relations, popularized by Tarski, serves as a natural benchmark for first-order navigational querying.  ...  Recently, nested regular expressions have been proposed to extend navigational querying to RDF graphs, i.e., ternary relations.  ...  It is worth noting that Versa, one of the earliest RDF query language proposals, is much more explicitly navigational than SPARQL, which evolved from an originally lightweight language for pattern matching  ... 
doi:10.1093/comjnl/bxu128 fatcat:tpfqwgjeqnbunhrbyjk65aa5y4

Semantic Web Application Development with LITEQ [chapter]

Martin Leinberger, Stefan Scheglmann, Ralf Lämmel, Steffen Staab, Matthias Thimm, Evelyne Viegas
2014 Lecture Notes in Computer Science  
To tackle these issues, we introduce LITEQ, a paradigm for integrating RDF data sources into programming languages and strongly typing the data.  ...  However, due to a lack of support it is still cumbersome to work with RDF data in modern, object-oriented programming languages, in particular if the data source is only available through a SPARQL endpoint  ...  Examples of graph traversal languages for RDF data are nSPARQL [13] , a language with focus on navigation through RDF data, or GuLP [4] , which can include preferential attachment into its queries.  ... 
doi:10.1007/978-3-319-11915-1_14 fatcat:p7botcka6fgxfgiffu6m7mmhia
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