Semantics and complexity of SPARQL

@article{Prez2009SemanticsAC,
  title={Semantics and complexity of SPARQL},
  author={Jorge P{\'e}rez and Marcelo Arenas and Claudio Guti{\'e}rrez},
  journal={ArXiv},
  year={2009},
  volume={abs/cs/0605124}
}
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. Among other complexity results, we show that the evaluation of general SPARQL patterns is PSPACE-complete. We identify a large class of SPARQL… Expand
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Chapter 1 On the Semantics of SPARQL
The Resource Description Framework (RDF) is the standard data model for representing information about World Wide Web resources. Jointly with its release as Recommendation of the W3C, the naturalExpand
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References

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Semantics and Complexity of SPARQL
TLDR
This paper addresses systematically the formal study of SPARQL, concentrating in its graph pattern facility, providing a compositional semantics, and proving there are normal forms, among others that the evaluation of SParQL patterns is PSPACE-complete. Expand
Foundations of SPARQL query optimization
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While studied in the context of a theoretically motivated set semantics, almost all results carry over to the official, bag-based semantics and therefore are of immediate practical relevance. Expand
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The formal semantics of SParQL is discussed, translations from SPARQL to Datalog with negation as failure are provided, and some useful and easy to implement extensions of SPARQ are proposed, which serve for direct implementations ofSPARQL on top of existing rules engines as well as a basis for more general rules and query languages onTop of RDF. Expand
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This chapter gives a detailed description of the semantics of this language, a query language called SPARQL, including all the features in the specification by the W3C such as blank nodes in graph patterns and bag semantics for solutions. Expand
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A transformation from SPARQL queries into the relational algebra, an intermediate language for the expression and analysis of queries that is widely used in the database area is described. Expand
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A new RDF query language called RQL is proposed, which is a typed functional language (a la OQL) and relies on a formal model for directed labeled graphs permitting the interpretation of superimposed resource descriptions by means of one or more RDF schemas. Expand
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