Re: D2RQ and Revelytix semantics

Hi Juan

Good analysis.
I just want to point out that the R2O mapping language [1] follows the 
same philosophy of the D2RQ. It is database-instance-only and is XML-based.
I can include the R2O examples in your document if you want. Maybe it 
would be good for comparison purposes.

Looking forward to Alex's presentation .

Boris


[1] http://www.cs.man.ac.uk/~ocorcho/documents/SWDB2004_BarrasaEtAl.pdf

Juan Sequeda wrote:
> Hi Richard, Alex and all
>
> I took the liberty of analyzing D2RQ and Revelytix mapping language 
> and compare it to the semantics that Marcelo and I have defined in 
> Datalog [1]. (BTW, Marcelo defined the semantics of Datalog in the 
> wiki also!) 
>
> Marcelo and I are still working on this so you can see a draft of what 
> we are doing in the following google doc (once we are done, we will 
> put it on the wiki.... tables in the wiki are a pain!)
>
> https://docs.google.com/document/pub?id=1APTqD2lJLRjwV6gmPKqDRqC3aT8bozHF0udIXndMNWQ 
>
> Please forgive me if I butchered the mapping language.
>
> Quick conclusion:
>
> - Both mapping languages are very similar
> - Both mapping languages have the semantics established as 
> Database-Instance-and-Schema Mapping [1] (there is a definition of 
> Classes and Properties). There is no way to formally prove this 
> because both languages don't have existing defined semantics (right?)
> - Revelytix language has different ways of saying the same thing for 
> sake of query optimization ( right?). (I personally believe this is 
> something we should avoid. Language and implementation details should 
> be separate... just look at SQL)
>
> Looking forward to Alex's presentation tomorrow!
>
>
> [1] http://www.w3.org/2001/sw/rdb2rdf/wiki/Database-Instance-Only_and_Database-Instances-and-Schema_Mapping
>
> Juan Sequeda
> +1-575-SEQ-UEDA
> www.juansequeda.com <http://www.juansequeda.com>