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
RDB.

Alexandre.

> 
> -David
>

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