D2RQ and Revelytix semantics

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