Re: Start discussion

Souri,

This is a good point. Lee was mentioning before that some would lean on
SPARQL CONSTRUCT.

Lee, Eric... comments?

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


On Mon, Mar 22, 2010 at 6:58 AM, Souripriya Das
<SOURIPRIYA.DAS@oracle.com>wrote:

> We must first debate why some members in the group think the SQL-query
> based approach (use of SQL queries and a "trivial" mapping) is not
> sufficient for viewing relational data as RDF.
>
> I have detailed this request for debate in my previous email:
> http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2010Mar/0057.html
>
> Note that SQL-Query based approach involves reading and transforming
> *relational* data (with the choice of using one or more of the following:
> INNER JOINs, OUTER JOINs, expressions, aggregate functions, table functions,
> OLAP functions, hierarchical queries (CONNECT BY), ...)) to produce custom
> results in the form of "logical" tables (with conventions for optionally
> defining instance URIs, rdf:type columns, and graph URIs, for various extent
> of customizations for producing RDF terms) that can then be easily
> transformed into RDF schema and instance triples via a mapping specification
> written using a simple mapping language.
>
> Thanks,
> - Souri.
>
> ----- Original Message -----
> From: marcelo.arenas1@gmail.com
> To: juanfederico@gmail.com
> Cc: Ahmed.Ezzat@hp.com, lee@thefigtrees.net, public-rdb2rdf-wg@w3.org
> Sent: Monday, March 22, 2010 4:36:42 AM GMT -05:00 US/Canada Eastern
> Subject: Re: Start discussion
>
> On Mon, Mar 22, 2010 at 5:56 AM, Juan Sequeda <juanfederico@gmail.com>
> wrote:
> > On Sun, Mar 21, 2010 at 11:49 PM, Ezzat, Ahmed <Ahmed.Ezzat@hp.com>
> wrote:
> >>
> >>
> >> Hi Juan,
> >>
> >> We have tasks for the use case.  I agree that I do not see enough
> >> discussion on the distribution list. It was agreed on we need the use
> case
> >> completed before diving deeper in the mapping language. This Tuesday let
> us
> >> discuss what is left on the use case. Our highest priority is to
> finalize
> >> what the team will be delivering sometime in April - higher priority
> than
> >> the semantics of the language.
> >
> > Great to know. I agree that we should get the use cases out the door
> asap.
> > I'm trying to do my share :)
> >>
> >>
> >> I agree for using Datalog in expressing the semantics of the mapping
> >> language; we should discuss that in the group. If I remember correctly,
> Andy
> >> Seaborne used Datalog in expressing the semantics of some SPARQL
> language
> >> constructs in the SPARQL WG...
> >
> > +1
> >>
> >>
> >> Lee, Independent of which approach you use, you need to validate the
> >> semantics of the mew language.  Advantage of Datalog, as it is based on
> >> logic, it is more expressive than relational algebra. Below is few pages
> >> about Datalog.
> >
> > Great set of slides. I honestly think that using datalog to define the
> > semantics should easy and we have a great team to get it done :)
>
> Yes, great set of slides. I also think that datalog is the right
> choice (and that we have a great team to get the work done :)
>
> Cheers,
>
> Marcelo
>
>
>