ACM TRANSACTIONS ON DATABASE SYSTEMS Volume: 34 Issue: 3 Article Number: 16 Published: AUG 2009
en_US
Identifier
dc.identifier.other
DOI: 10.1145/1567274.1567278
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/125956
General note
dc.description
Artículo de publicación ISI
en_US
Abstract
dc.description.abstract
SPARQL is the W3C candidate recommendation query lan-
guage for RDF. In this paper we address systematically the formal study
of SPARQL, concentrating in its graph pattern facility. We consider for
this study simple RDF graphs without special semantics for literals and
a simplified version of filters which encompasses all the main issues.
We provide a compositional semantics, prove there are normal forms,
prove complexity bounds, among others that the evaluation of SPARQL
patterns is PSPACE-complete, compare our semantics to an alternative
operational semantics, give simple and natural conditions when both se-
mantics coincide and discuss optimization procedures.