Validating Shacl Constraints over a Sparql Endpoint

@inproceedings{Corman2019ValidatingSC,
  title={Validating Shacl Constraints over a Sparql Endpoint},
  author={Julien Corman and Fernando Florenzano and Juan L. Reutter and Ognjen Savkovic},
  booktitle={SEMWEB},
  year={2019}
}
shacl (Shapes Constraint Language) is a specification for describing and validating RDF graphs that has recently become a W3C recommendation. While the language is gaining traction in the industry, algorithms for shacl constraint validation are still at an early stage. A first challenge comes from the fact that RDF graphs are often exposed as sparql endpoints, and therefore only accessible via queries. Another difficulty is the absence of guidelines about the way recursive constraints should be… 

Reasoning about Explanations for Non-validation in SHACL (Extended Abstract)

TLDR
In this paper, inspired by works on logic-based abduction and database repairs, the problem of explaining non-validation of SHACL constraints is studied using the notion of a repair, i.e., a collection of additions and deletions whose application on an input graph results in a repaired graph that does satisfy the given SHACl constraints.

SHACL Satisfiability and Containment

TLDR
This paper provides a translation to a new first-order language, called SCL, that precisely captures the semantics of SHACL w.r.t. satisfiability and containment and provides the detailed map of decidability and complexity results of the aforementioned decision problems for differentSHACL sublanguages.

SHACL Constraint Validation during SPARQL Query Processing

TLDR
This work proposes a query engine that is able to efficiently evaluate which instances in the knowledge graph fulfill the requirements from the SHACL shape schema and annotate the SPARQL query result with this metadata, adding the dimension of explainability to SParQL query processing.

Magic Shapes for SHACL Validation

TLDR
The approach can be a stepping stone towards validators for full SHACL, and that it can significantly improve the performance of the only prototype validator that currently supports full recursion and negation.

Magic Shapes for Validation in SHACL

TLDR
The Shape Constraint Language (SHACL) was recently standardized by the W3C as a formalism for checking the quality of RDF graphs and leaves undefined the semantics of recursive constraints, i.e., constraints that involve cyclic dependencies.

Expressiveness of SHACL Features

TLDR
This paper shows that each of the four features of SHACL expressions can use four fundamental features that are not so common in description logics: zero-or-one path expressions; equality tests; disjointness tests; and closure constraints are primitive.

Trav-SHACL: Efficiently Validating Networks of SHACL Constraints

TLDR
Trav-SHACL, a SHACL engine capable of planning the traversal and execution of a shape schema in a way that invalid entities are detected early and needless validations are minimized, and reduces validation time by a factor of up to 28.93 compared to the state of the art.

Shape Fragments

TLDR
This paper defines the extraction mechanism formally, building on recently proposed SHACL formalizations, establishes correctness properties, which relate shape fragments to notions of provenance for database queries, and compares shape fragments with SPARQL queries.

Deciding SHACL Shape Containment through Description Logics Reasoning (Extended Version)

TLDR
This work maps SHACL shape graphs into description logic axioms such that shape containment can be answered by description logic reasoning and identifies several, increasingly tight syntactic restrictions ofSHACL for which this approach becomes sound and complete.

SHACL2SPARQL: Validating a SPARQL Endpoint against Recursive SHACL Constraints

TLDR
Shacl2sparql is presented, a tool that validates an rdf graph stored as a sparql endpoint against possibly recursive shacl constraints and improves upon the original algorithm with a wider range of natively supported constraint operators, sparql query optimization techniques, and a mechanism to explain invalid targets.

References

SHOWING 1-10 OF 10 REFERENCES

Semantics and Validation of Recursive SHACL [Extended Version]

TLDR
This paper proposes a concise formal semantics for the so-called “core constraint components” of SHACL, which handles arbitrary recursion, while being compliant with the current standard.

Semantics and Validation of Recursive SHACL

TLDR
With the popularity of RDF as an independent data model came the need for specifying constraints on RDF graphs, and for mechanisms to detect violations of such constraints, and SHACL, a recent W3C recommendation, leaves open the problem of validation against recursive constraints.

Complexity and Expressiveness of ShEx for RDF

TLDR
To curb the high computational complexity of validation, this work proposes a natural notion of determinism and shows that multi-type validation for the class of deterministic schemas using single-occurrence regular bag expressions (SORBEs) is tractable.

Integrity Constraints in OWL

TLDR
This paper presents an alternative IC semantics for OWL that allows applications to work with the CWA and the weak UNA and shows that IC validation can be reduced to query answering under certain conditions.

Test-driven evaluation of linked data quality

TLDR
This work presents a methodology for test-driven quality assessment of Linked Data, which is inspired by test- driven software development, and argues that vocabularies, ontologies and knowledge bases should be accompanied by a number of test cases, which help to ensure a basic level of quality.

Bridging the gap between OWL and relational databases

TLDR
This work proposes an extension of OWL with ICs that captures the intuition behind ICs in relational databases, and discusses the algorithms for checking IC satisfaction for different types of knowledge bases, and shows that, if the constraints are satisfied, one can disregard them while answering a broad range of positive queries.

A Tractable Notion of Stratification for SHACL

TLDR
A restriction on the usage of negation in SHACL “core constraint components” constraints, called strict stratification, which guarantees tractability of graph validation, is introduced.

Semantics and Validation of Shapes Schemas for RDF

We present a formal semantics and proof of soundness for shapes schemas, an expressive schema language for RDF graphs that is the foundation of Shape Expressions Language 2.0. It can be used to

Recursion in SPARQL

TLDR
This paper provides a formal syntax and semantics for this proposal, study its theoretical properties, and develop algorithms for evaluating it in practical scenarios, and demonstrates its performance on several synthetic and real world datasets.

Extended version of the paper, prototype implementation and experiments material