2015/03/16 by Olaf Hartig, Hartig, Olaf, Giuseppe Pirrò +1
Biochemistry, Genetics and Molecular Biology · Computer Science · #Advanced Database Systems and Queries #Biomedical Text Mining and Ontologies #Databases (cs.DB) #FOS: Computer and information sciences #Semantic Web and Ontologies
paper · pdf · doi:10.48550/arxiv.1503.04831
openalex publication_date 2015/03/16 · openalex created_date 2022/09/10 · openalex updated_date 2026/07/28
As of today, there exists no standard language for querying Linked Data on\nthe Web, where navigation across distributed data sources is a key feature. A\nnatural candidate seems to be SPARQL, which recently has been enhanced with\nnavigational capabilities thanks to the introduction of property paths (PPs).\nHowever, the semantics of SPARQL restricts the scope of navigation via PPs to\nsingle RDF graphs. This restriction limits the applicability of PPs on the Web.\nTo fill this gap, in this paper we provide formal foundations for evaluating\nPPs on the Web, thus contributing to the definition of a query language for\nLinked Data. In particular, we introduce a query semantics for PPs that couples\nnavigation at the data level with navigation on the Web graph. Given this\nsemantics we find that for some PP-based SPARQL queries a complete evaluation\non the Web is not feasible. To enable systems to identify queries that can be\nevaluated completely, we establish a decidable syntactic property of such\nqueries.\n