Re: Relationship between EricP's default mapping and Datalog rules approach?

 From a 30,000 foot level what we need is:

1. Default mapping rules
Juan has datalog rules.  But we may want to express these in English as 
well such as:
A table maps to a class, columns map to data properties, PK-FK 
relationships map to object properties ...

2. Customization rules
Last week Marcelo presented some datalog rules.  I think we may want to 
express the RHS as a
SQL query/view.  We may also need a XML syntax

3. From the datalog/SQL rules we should be able to derive the SPARQL 
syntax.  Souri, Seema and I
had a chat about this.  Needs a bit more thinking.

How does that sound as a plan going forward?

All the best, Ashok


Juan Sequeda wrote:
> Harry,
>
> On Sun, Jul 18, 2010 at 8:26 AM, Harry Halpin <hhalpin@w3.org 
> <mailto:hhalpin@w3.org>> wrote:
>
>     While I enjoyed the talk last week, I was wondering about the
>     relationship
>     between Eric's proposed direct mapping [1] and the rules put
>     forward last
>     week by Marcelo [2]. This question goes to both, and the entire
>     working
>     group.
>
>     One of the advantages of Eric's default mapping mechanism [1] is
>     that it
>     allows relational data to be expressed in RDF without the author
>     of the
>     mapping knowing *any* rules or having any ontology that he or she
>     wants to
>     map their relational data to.
>
>
> This is exactly the same as the Database-Instance-Only mapping. 
>
>
>      This is one of the requirements of our charter, although of course we
>     want mappings to other vocabularies to be possible. Remember, this
>     can be
>     thought of as a two-step process, where the first step is a default
>     mapping, and then later mappigs (via Datalog rules, RIF, SQL or
>     whatever)
>     could then transform
>
>
> In this simple approach, the predicates are the only things that are 
> going to be mapped:
>
> ex:name ->foaf:name
> ....
>
> So you could have a system that can automatically generate:
>
> Triple(s, "ex:name", name) <- student(s_id, name), generateURI(s_id, s)  
>
> or the user can write the mapping with the :
>
> Triple(s, "foaf:name", name) <- student(s_id, name), generateURI(s_id, s)
>
>
>     Could we take the rules given earlier [2] and then use these to
>     produce
>     the same effects as Eric's direct mapping proposal? Could someone
>     specify
>     this in detail?
>
>
> The Database-Instance-Only mapping does that.
>  
>
>     Then the default mapping could be seen as a certain default
>     application of
>     rules, an application that *can* be changed.
>
>
> The rules defines the semantics of what needs to be implemented in an 
> application
>  
>
>
>                cheers,
>                     harry
>
>     [1] http://www.w3.org/2001/sw/rdb2rdf/directGraph/
>     [2]http://web.ing.puc.cl/~marenas/W3C/mapping_language.txt
>     <http://web.ing.puc.cl/%7Emarenas/W3C/mapping_language.txt>
>
>
>
>

Received on Sunday, 18 July 2010 16:27:03 UTC