Re: Direct Mapping

On Mon, Sep 6, 2010 at 11:00 PM, Richard Cyganiak <richard@cyganiak.de>wrote:

>
> On 7 Sep 2010, at 04:43, Juan Sequeda wrote:
>
>> On Mon, Sep 6, 2010 at 10:31 PM, Richard Cyganiak <richard@cyganiak.de
>> >wrote:
>>
>>> So there are at least TWO DISTINCT AUDIENCES for the direct mapping spec:
>>>
>>>
>>> 1. RDB2RDF vendors who implement R2RML engines and want to equip their
>>> systems with functionality similar to D2R's "generate-mapping" script,
>>> which
>>> generates a simple canonical R2RML file for a given database, with the
>>> intent of allowing further customization of the R2RML file by the user.
>>>
>>> 2. RDB2RDF vendors who implement RIF-based engines (or engines based on
>>> any
>>> other RDF-to-RDF transformation language). Users of these engines will
>>> write
>>> RIF rules that transform the direct graph into a custom graph. Users and
>>> vendors of these systems don't need the R2RML language.
>>>
>>
>> Great clarification and +1 on everything.
>>
>> Given that we are clear that there are two audience, the only thing I'm
>> saying is that if we are going to write a document on the Direct Mapping,
>> which one of the audiences is expecting to see a R2RML file... we need to
>> have a R2RML syntax before we have a Direct Mapping document ready.
>>
>
> Again, the “RIF-friendly audience” in 2. doesn't want to see R2RML, and is
> better served by a spec that simply describes the shape of the resulting
> direct graph.
>
> The “R2RML-friendly audience” in 1. would be reasonably well served by
> either approach -- describing the shape of the direct graph, or describing a
> canonical “direct R2RML file”.
>
> My preference would be to normatively specify the direct mapping as a
> direct graph. And have an informative appendix that describes an algorithm
> for creating the canonical direct R2RML file that produces the direct graph.
>
>
I wonder what the rest of the group has to say about this.

>
>  Hence my suggestion to put priority on syntax right now.
>>
>
> I sort of agree. But I don't see a dependency of the direct mapping on
> R2RML.
>
> Richard