245 Hits in 2.9 sec

The multiset semantics of SPARQL patterns [article]

Renzo Angles, Claudio Gutierrez
2016 arXiv   pre-print
The paper determines the algebraic and logic structure of the multiset semantics of the core patterns of SPARQL.  ...  union and except), and the multiset non-recursive Datalog with safe negation.  ...  Semantics of SPARQL graph patterns.  ... 
arXiv:1610.04315v1 fatcat:hm6yyhw4izg4biqkrna5huiolu

SPARQL beyond Subgraph Matching [chapter]

Birte Glimm, Markus Krötzsch
2010 Lecture Notes in Computer Science  
We extend the Semantic Web query language SPARQL by defining the semantics of SPARQL queries under the entailment regimes of RDF, RDFS, and OWL.  ...  The proposed extensions are part of the SPARQL 1.1 Entailment Regimes working draft which is currently being developed as part of the W3C standardization process of SPARQL 1.1.  ...  We thank the members of the SPARQL working group for valuable comments and suggestions.  ... 
doi:10.1007/978-3-642-17746-0_16 fatcat:qwwydaftwfavvapxlphvmpybri

Query Nesting, Assignment, and Aggregation in SPARQL 1.1

Mark Kaminski, Egor V. Kostylev, Bernardo Cuenca Grau
2017 ACM Transactions on Database Systems  
In this paper we provide an in-depth formal analysis of the semantics and expressive power of these new constructs as defined in the SPARQL 1.1 specification, and hence lay the necessary foundations for  ...  A Sparql PD query is in s-normal form if it has either the form Distinct (Project (X , P )) with P subquery-free, or the form Project (X , P ) where all subquery patterns in P are of the form Distinct  ...  Lists of Solutions. We have defined the semantics of patterns and queries uniformly in terms of multisets of mappings, which simplifies the algebra by avoiding numerous type conversions.  ... 
doi:10.1145/3083898 fatcat:76iwfmwenreufej3mszesjcijq

Foundations of an Alternative Approach to Reification in RDF [article]

Olaf Hartig, Bryan Thompson
2021 arXiv   pre-print
This document defines extensions of the RDF data model and of the SPARQL query language that capture an alternative approach to represent statement-level metadata.  ...  One of the great advantages of the proposed approach is that it clarifies a means to (i) understand sparse matrices, the property graph model, hypergraphs, and other data structures with an emphasis on  ...  The basis for defining the semantics of SPARQL ⋆ is an algebra over multisets of solution ⋆ mappings that resembles the standard SPARQL algebra (which is defined over multisets of ordinary solution mappings  ... 
arXiv:1406.3399v3 fatcat:fqbq2elrfzggnczc4tchwdl2vi

A Context-Based Semantics for SPARQL Property Paths over the Web (Extended Version) [article]

Olaf Hartig, Giuseppe Pirro
2015 arXiv   pre-print
However, the semantics of SPARQL restricts the scope of navigation via PPs to single RDF graphs. This restriction limits the applicability of PPs on the Web.  ...  Given this semantics we find that for some PP-based SPARQL queries a complete evaluation on the Web is not feasible.  ...  In addition to these algebra operators, the SPARQL standard introduces auxiliary functions to define the semantics of PP patterns of the form α, path * , β .  ... 
arXiv:1503.04831v1 fatcat:epei4sx5gngcdncyamscvd7jn4

semQA: SPARQL with Idempotent Disjunction

E.P. Shironoshita, Y.R. Jean-Mary, R.M. Bradley, M.R. Kabuka
2009 IEEE Transactions on Knowledge and Data Engineering  
The SPARQL LeftJoin abstract operator is not distributive over Union; this limits the algebraic manipulation of graph patterns, which in turn restricts the ability to create query plans for distributed  ...  In this paper, we present semQA, an algebraic extension for the SPARQL query language for RDF, which overcomes this issue by transforming graph patterns through the use of an idempotent disjunction operator  ...  Acknowledgments This research has been supported through Grant 1R43RR018667 from the National Center for Research Resources, US National Institutes of Health, and Grant 1R43CA132293 from the National Cancer  ... 
doi:10.1109/tkde.2008.91 pmid:19915690 pmcid:PMC2776754 fatcat:cc3ojsobvfbj3iolpubrlwt2gu

A Context-Based Semantics for SPARQL Property Paths Over the Web [chapter]

Olaf Hartig, Giuseppe Pirrò
2015 Lecture Notes in Computer Science  
However, the semantics of SPARQL restricts the scope of navigation via PPs to single RDF graphs. This restriction limits the applicability of PPs on the Web.  ...  Given this semantics we find that for some PP-based SPARQL queries a complete evaluation on the Web is not feasible.  ...  SPARQL 1.1 W3C property paths semantics. Data Model The standard SPARQL evaluation function for PP patterns (cf.  ... 
doi:10.1007/978-3-319-18818-8_5 fatcat:lsttlqjezngw5abomjt2n43g2q

Negation in SPARQL [article]

Renzo Angles, Claudio Gutierrez
2016 arXiv   pre-print
Then, we study the expressive power of the corresponding negation operators. At this point, we identify a core SPARQL algebra which could be used instead of the W3C SPARQL algebra.  ...  This paper presents a thorough study of negation in SPARQL. The types of negation supported in SPARQL are identified and their main features discussed.  ...  consisting of exactly the empty mapping µ 0 .  ... 
arXiv:1603.06053v4 fatcat:exwwk76havflldeft5ew6dbpvy

Using SPARQL with RDFS and OWL Entailment [chapter]

Birte Glimm
2011 Lecture Notes in Computer Science  
The query language further contains capabilities for querying for optional basic graph patterns, alternative graph patterns etc. We first introduce the main features of SPARQL as a query language.  ...  Apart from the features of SPARQL 1.0, we also briefly introduce the new features of SPARQL 1.  ...  The simplest form of a WHERE clause consists of a basic graph pattern (BGP), but we can also construct more complex graph patterns by combining smaller patterns in various ways that are described in detail  ... 
doi:10.1007/978-3-642-23032-5_3 fatcat:hntq6ag5ijeafgquqkwhwncmsy

EXISTStential Aspects of SPARQL

Peter F. Patel-Schneider, David Martin
2016 International Semantic Web Conference  
Substitution destroys some of the aspects of SPARQL that make it suitable as a data access language. As well, substitution causes problems in the SPARQL algebra and produces counterintuitive results.  ...  The SPARQL 1.1 Query Language [1] permits patterns inside FILTER expressions using the EXISTS construct, specified by using substitution.  ...  Initial will be used to set up the initial multiset of solution mappings inside an EXISTS. This definition eliminates all the semantic anomalies resulting from EXISTS.  ... 
dblp:conf/semweb/Patel-Schneider16 fatcat:m6dhvcbvprbltn3yzwfjklriwq

SPARQL with property paths on the Web

Olaf Hartig, Giuseppe Pirrò, Fabien Gandon, Marta Sabou, Harald Sack, Fabien Gandon, Marta Sabou, Harald Sack
2017 Semantic Web Journal  
Recently, SPARQL has been extended with a navigational feature called property paths (PPs). However, the semantics of SPARQL restricts the scope of navigation via PPs to single RDF graphs.  ...  Given these semantics, we find that for some PP-based SPARQL queries a complete evaluation on the Web is not possible.  ...  Olaf Hartig's work has been funded by the German Government, Federal Ministry of Education and Research under the project number 03WKCJ4D.  ... 
doi:10.3233/sw-160237 fatcat:baiq7beuenhfhf5ktdr2kom5ta

Provenance for SPARQL Queries [chapter]

Carlos Viegas Damásio, Anastasia Analyti, Grigoris Antoniou
2012 Lecture Notes in Computer Science  
We provide an approach capable of providing provenance information for a large and significant fragment of SPARQL 1.1, including for the first time the major non-monotonic constructs under multiset semantics  ...  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.  ...  The result is the first approach that provides adequate provenance information for OPTIONAL, MINUS and NOT EXISTS constructs under the multiset (bag) semantics of SPARQL.  ... 
doi:10.1007/978-3-642-35176-1_39 fatcat:mscaozjpbfhxzdk7ubs4rrzozq

RSP-QL Semantics

Daniele Dell'Aglio, Emanuele Della Valle, Jean-Paul Calbimonte, Oscar Corcho
2014 International Journal on Semantic Web and Information Systems (IJSWIS)  
In this work, we propose RSP-QL, a comprehensive model that formally defines the semantics of an RSP system.  ...  In the last years data and query languages have been proposed to extend both RDF and SPARQL for streams and continuous processing, under the name of RDF Stream Processing -RSP.  ...  Acknowledgments Supported by the Opensense2 project, the IBM faculty-award 2013 granted to prof. E. Della Valle and the IBM PhD Fellowship Award 2014 granted to D. Dell'Aglio.  ... 
doi:10.4018/ijswis.2014100102 fatcat:lq3gz7j7bze57plqohe6s6sg34

Extending SPARQL for Recommendations

Victor Anthony Arrascue Ayala, Martin Przyjaciel-Zablocki, Thomas Hornung, Alexander Schätzle, Georg Lausen
2014 Proceedings of Semantic Web Information Management on Semantic Web Information Management - SWIM'14  
RecSPARQL fills this gap by extending the syntax and semantics of SPARQL to enable a generic and flexible way for collaborative filtering and content-based recommendations over arbitrary RDF graphs.  ...  Our experiments on the MovieLens data set demonstrate the applicability of our approach.  ...  some formalisms based on the semantic of SPARQL 1.1.  ... 
doi:10.1145/2630602.2630604 dblp:conf/sigmod/AyalaPHSL14 fatcat:j745wyg6hnatte5726pdk7l4v4

SPARQL1.1: New Features and Friends (OWL2, RIF) [chapter]

Axel Polleres
2010 Lecture Notes in Computer Science  
e.g. Blanknodes: "existential variables in the  ...  g3) . }  The GRAPH ?g construct allows a pattern to match against one of the named graphs in the RDF dataset. The URI of the matching graph is bound to ?  ...  -BGPs -P1 P2 -P FILTER R -P1 UNION P2 -P1 OPTIONAL P2  Semantics  eval(D(G), graph pattern) … D is a dataset, G is the "active graph" recursively defined for all graph patterns in Section 12.  ... 
doi:10.1007/978-3-642-15918-3_3 fatcat:vbtjrsucvnhcnoj7o3j45pzlhy
« Previous Showing results 1 — 15 out of 245 results