Re: D2RQ and Revelytix semantics

Alex,

Thanks for you comments. The objective is to classify everything (class
types, data type property, object type property, user-generated
rule/queries). I think this covers it all.

Is there anything that I have wrong or I have understood incorrectly?

After putting some thought into this, I believe existing languages such as
D2RQ and Revelytix have the semantics of Database-Instance-and-Schema
mapping while the Triplify approach has the semantics of
Database-Instance-Only and uses SQL as the mapping language.

Juan Sequeda
+1-575-SEQ-UEDA
www.juansequeda.com


On Mon, Jul 26, 2010 at 4:05 PM, Alex Miller <alexdmiller@yahoo.com> wrote:

> Thanks!  I think this is largely correct.  I was working on simple examples
> myself but you've done a lot more than I have. :)
>
>
> ------------------------------
> *From:* Juan Sequeda <juanfederico@gmail.com>
> *To:* Richard Cyganiak <richard@cyganiak.de>; Alex Miller <
> alexdmiller@yahoo.com>; public-rdb2rdf-wg@w3.org
> *Sent:* Mon, July 26, 2010 3:51:24 PM
> *Subject:* 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
>