Re: Direct Mapping

>
>
>
> Let's see if I understand the implied mechanics. Option 1 directly
> specifies the RDF graph implied by a database (for any tuple in the
> database, you can say exactly what triples are in the direct
> graph). Option 2 specifies a mapping language, with certain mapping
> semantics, and with a default configuration. The default graph is the
> products of applying the mapping semantics for a default configuration
> to a database.
>
>
Option 2 uses R2RML.

I see the two options this way

Option 1:

1) We (the WG) present the direct mapping rules in order to generate a
direct RDF graph from a RDB
2) Database vendors (oracle, db2, etc) implement these mapping rules OR
RDB2RDF systems on top of a RDB can read the database dictionary and run
these mapping rules
3) You click the button "Generate Direct RDF"
4) Outcomes your RDF
5) Use RDF to RDF tools (sparql constructs, etc) to map to other
vocabularies

Option 2:

1) We (the WG) present the direct mapping rules in order to generate a
direct RDF graph from a RDB
2) Database vendors (oracle, db2, etc) implement these mapping rules OR
RDB2RDF systems on top of a RDB can read the database dictionary and run
these mapping rules
3) You click the button "Generate Direct RDF"
4) Outcomes your RDF
5) Out comes the R2RML mapping file that generated the Direct RDF Graph
6) A user can modify the R2RML mapping file in order to change vocabularies,
etc


So.. if we agree on this.. we are practically then talking about the same
thing. Only difference is that in Option 2 we are outputing the direct
mapping also in R2RML. Otherwise.. why would we need R2RML??????


>
> > So you think that a direct mapping shouldn't output the R2RML file? I
> think
> > it should because this file is the basis for people to work on and start
> > customizing it.
>
> The RDF rules folks will have everything they need with option 1. They
> can write/share rules in RIF, SPIN, n3, ... which transform the
> default graph to popular ontologies. Simple implementations will
> materialize these graphs, and arguably cooler implementations will
> work directly on the relational data, but that's really implementation
> detail; all they need is the default graph.
>
>
> > > Hence I'm with Eric here.
> > >
> > >
> > >  The automatic mapping file that is generated in D2R is equivalent to
> the
> > >> Direct Mapping (right Richard?).
> > >>
> > >
> > > Well I'd say the *graph* produced by an auto-generated D2R mapping file
> is
> > > equivalent to the direct mapping.
> > >
> >
> > and I'd call the auto-generated D2R mapping file the Direct Mapping file.
> So
> > D2R does option 2 then.
> >
> > >
> > > Best,
> > > Richard
>
> --
> -ericP
>

Received on Monday, 6 September 2010 21:58:49 UTC