Data Provenance for SHACL

Abstract

In constraint languages for RDF graphs, such as ShEx and SHACL, constraints on nodes and their properties are known as “shapes”. Using SHACL, we propose in this paper the notion of neighborhood of a node 𝑣 satisfying a given shape in a graph 𝐺. This neighborhood is a subgraph of 𝐺, and provides data provenance of 𝑣 for the given shape. We establish a correctness property for the obtained provenance mechanism, by proving that neighborhoods adhere to the Sufficiency requirement articulated for provenance semantics for database queries. As an additional benefit, neighborhoods allow a novel use of shapes: the extraction of a subgraph from an RDF graph, the so-called shape fragment. We compare shape fragments with SPARQL queries. We discuss implementation strategies for computing neighborhoods, and present initial experiments demonstrating that our ideas are feasible.