Re: Start discussion

On Sun, Mar 21, 2010 at 7:51 PM, Lee Feigenbaum <> wrote:

> On 3/21/2010 8:26 PM, Juan Sequeda wrote:
>> Hi Everybody,
>> There has been no discussion at all on the list, and that honestly
>> worries me.
> I share this concern, which is one reason that I decided to join the group
> and try to add what I can.
Glad you are part of the discussion!

>  I know that we need to have a Use Case documents, but it is not
>> completely clear to me what else we need to turn in and by when.
>> One issue that I personally feel than needs to be settled is the
>> semantics of the language. One we have this defined, it is just a matter
>> of deciding on what is the syntax. I don't think we have made much
>> progress on this issue. I have proposed to develop the semantics of the
>> mapping language in datalog. I'd be up for working on this in
>> conjunction with Marcelo Arenas and Dan Miranker.
> Ideally, I'd hope that the semantics of the language follow from the
> requirements which follow from the use cases.

So is this the timeline? First get the use cases done, and then work on
everything else? I'm sure we can start on the basics, as we have done
already with a syntax, without having all the use cases.

> As far as datalog, I know next to nothing about it, so my questions are
> probably naive. Is there a datalog standard that we will be able to
> normatively reference if the semantics of the language are given in datalog?

mmm, I'm not sure. Marcelo?

> Also, I'm not sure if separating the syntax & semantics is definitely an
> easy thing to do. I know that there are people on the group who advocate
> that the mapping language be based on SPARQL CONSTRUCT queries combined with
> a default mapping from the relational model to the RDF model. In this case,
> I imagine it would make more sense to lean on the SPARQL algebra/semantics?

Well this is what we exactly need to discuss. I talk about datalog, because
the work of Marcelo et al shows that SPARQL is equivalent to non recursive
datalog, and therefore equivalent to relational algebra.


 What else should we be having discussions on? The clock is ticking.
> Juan Sequeda
> +1-575-SEQ-UEDA
> <>

Received on Monday, 22 March 2010 04:49:12 UTC