Re: Start discussion

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:

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.

- Souri.

----- Original Message -----
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 <> wrote:
> On Sun, Mar 21, 2010 at 11:49 PM, Ezzat, Ahmed <> 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 :)



Received on Monday, 22 March 2010 12:00:49 UTC