Re: Keeping R2RML free of Direct Mapping dependency (ISSUE-25)

On Tue, 2011-04-26 at 09:53 -0500, David McNeil wrote:
>         >
>         > > If the user wants a hybrid of these two models then they
>         can generate the Direct Mapping for an RDB and then replace
>         parts of it with a hand-crafted R2RML mapping.
>         > >
>         >
>         > I am not sure I understand that one. You mean generate an
>         R2RML that would correspond to a Direct Mapping?
>         >
>         >
>         > What I mean is to use a Direct Mapping tool to produce an
>         R2RML mapping file for an RDB.
>         Yes, that is what I meant. An R2RML representation of the DM
>         results for that particular RDB.
>         If we go down that route, it would be worthwhile having an
>         appendix in either the r2rml or the dm document that gives a
>         precise mapping of the dm to r2rml. This should not be left to
>         implementers to be figured out separately.
> Agreed. I was thinking the Direct Mapping was expressed in terms of
> R2RML, but I see now that is not the case.

The Direct Mapping was never intended to be "expressed in terms of
R2RML". But I agree that there could a section about it in the spec.
Just remember this will never be the normative definition of the Direct
Mapping. And the mapping itself will be parameterized by an instance of


> -David

Received on Tuesday, 26 April 2011 15:11:46 UTC