[JENA-2132] Rename.java lacks RDFStar support

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Jena 4.1.0
• Fix Version/s: Jena 4.2.0
• Component/s: ARQ
• Assignee: Andy Seaborne
• Reporter: Claus Stadler
• Created: 13/Jul/21 11:37
• Updated: 16/Sep/21 11:26
• Resolved: 14/Jul/21 20:42

Description

This is a follow up to JIRA-2107 (RDF Star performance issue with non-concrete node triples)

The NodeTransformers in Rename.java lacks renaming of variables in RDFStar NodeTriples.
A common side effect of this incomplete renaming is that the substitution provided for JIRA-2107 cannot be applied resulting in extremely bad query performance.

        Query query = QueryFactory.create
                ( "SELECT COUNT(*) {\n"
                + "  SELECT ?src {\n"
                + "    ?src  <urn:connectedTo>  ?tgt .\n"
                + "    << ?src <urn:connectedTo> ?tgt >>\n"
                + "                  <urn:hasValue>  ?v\n"
                + "  }\n"
                + "}"
                );

        Op op = Algebra.compile(query);
        Op op2 = TransformScopeRename.transform(op);
        System.out.println(op2);

Actual:

(project (?.1) (extend ((?.1 ?.0)) (group () ((?.0 (count))) (project (?src)
        (bgp
          (triple ?src <urn:connectedTo> ?/tgt)
          (triple << ?src <urn:connectedTo> ?tgt >> <urn:hasValue> ?/v)
                                            ^^^^
        )))))

Expected:

(project (?.1) (extend ((?.1 ?.0)) (group () ((?.0 (count))) (project (?src)
        (bgp
          (triple ?src <urn:connectedTo> ?/tgt)
          (triple << ?src <urn:connectedTo> ?/tgt >> <urn:hasValue> ?/v)
                                            ^^^^^
        )))))

Issue Links

• links to: GitHub Pull Request #1028