[westurner]

With RDF* and SPARQL* ("RDF-star" and "SPARQL-star") how are triple (or quad) stores still distinct from property graphs?

RDFS and SHACL (and OWL) are optional in a triple store, which expects the subject and predicate to be string URIs, and there is an object datatype and optional language:

  (?s ?p ?o <datatype> [lang])

  (?subject:URI, ?predicate:URI, ?object:datatype, object_datatype, [object_language])

RDFS introduces rdfs:domain and rdfs:range type restrictions for Properties, and rdfs:Class and rdfs:subClassOf.

`a` means `rdf:type`; which does not require RDFS:

  ("#xyz", a,        "https://schema.org/Thing")
  ("#xyz", rdf:type, "https://schema.org/Thing")

Quad stores have a graph_id string URI "?g" for Named Graphs:

  (?g ?s ?p ?o)

  ("https://example.org/ns/graphs/0", "#xyz", a, "https://schema.org/Thing")

  ("https://example.org/ns/graphs/1", "#xyz", a, "https://schema.org/ScholarlyArticle")

There's a W3C CG (Community Group) revising very many of the W3C Linked Data specs to support RDF-star: https://www.w3.org/groups/wg/rdf-star

Looks like they ended up needing to update basically most of the current specs: https://www.w3.org/groups/wg/rdf-star/tools

"RDF-star and SPARQL-star" (Draft Community Group Report; 08 December 2022) https://w3c.github.io/rdf-star/cg-spec/editors_draft.html

GH topics: rdf-star, rdfstar: https://github.com/topics/rdf-star, https://github.com/topics/rdfstar

pyDatalog does datalog with SQLAlchemy and e.g. just the SQLite database: https://github.com/pcarbonn/pyDatalog ; and it is apparently superseded by IDP-Z3: https://gitlab.com/krr/IDP-Z3/

From https://twitter.com/westurner/status/1000516851984723968 :

> A feature comparison of SQL w/ EAV, SPARQL/SPARUL, [SPARQL12 SPARQL-star, [T-SPARQL, SPARQLMT,]], Cypher, Gremlin, GraphQL, and Datalog would be a useful resource for evaluating graph query languages.

> I'd probably use unstructured text search to identify the relevant resources first.