Marcelo Arenas, Claudio GutierrezJorge Pérez. Foundations of RDF Databases. In Reasoning Web: Semantic technologies for information systems – 5th International Summer School, S. Tessaris and E. Franconi, editors, volume 5689 of Lecture Notes in Computer Science, pages 158-204, Springer, 2009. (2009)

Foundations of RDF Databases

Revista : Reasoning Web: Semantic technologies for information systems - 5th International Summer School
Páginas : 158-204
Tipo de publicación : Conferencia No DCC

Abstract

The goal of this paper is to give an overview of the basics of the theory of RDF databases. We provide a formal definition of RDF
that includes the features that distinguish this model from other graph data models. We then move into the fundamental issue of querying RDF data. We start by considering the RDF query language SPARQL, which is a W3C Recommendation since January 2008. 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 the evaluation of SPARQL queries, showing that a natural fragment of this language has some good properties
in this respect. We furthermore study the expressive power of
SPARQL, by comparing it with some well-known query languages such as relational algebra. We conclude by considering the issue of querying RDF data in the presence of RDFS vocabulary. In particular, we present a recently proposed extension of SPARQL with navigational capabilities.