ISSUE-73 (section11-cleanup): Section 11 cleanup [R2RML]

ISSUE-73 (section11-cleanup): Section 11 cleanup [R2RML]

Raised by: Richard Cyganiak
On product: R2RML

This is part of David's LC feedback on R2RML.

It's about various things in Section 11 – the algorithm for generating the output dataset. We should wait with this until ISSUE-68 and ISSUE-72 are addressed


* "Target graphs, a set of zero or more IRIs" - To my reading of the steps, the target graph is either a single IRI (i.e. rr:defaultGraph) or a set of IRIs. I don't think it is ever a set of size zero. Futhermore, I think the steps above need to be changed to produce singleton sets of rr:defaultGraph.

* "For each possible combination <s, p, o>" - For me this is a confusing way to describe the process. I don't think it is helpful to describe the subjects, predicates, and objects as sets and then take the cross-product of them. As far as I can tell this description only works in the document because the subjects, predicates, and objects are only ever singleton sets. Furthermore the steps are not written to produce sets. So I would change the description of "adding triples to the output dataset" to define subject, predicate, and object as single values. Then taking those single values and generating triples for each value in Target graphs.

* "A term map is a function that generates a set of RDF terms from a logical table row." - This statement is slightly different from the statement in section 7: "A term map is a function that generates an RDF term from a logical table row.". I think these two statements should match.

* This section seems to have two different positions running through it:
    a) term maps produce a set of RDF terms (where the set is either empty or a singleton set?) 
    b) term maps produce an RDF term or nothing
  It seems to me that we need to pick one or the other of these positions and make all the sentences consistent with that positions (both here and in earlier sections like section 7).

Received on Monday, 7 November 2011 16:30:27 UTC