Re: Comments on the SPARQL protocol

Hi Kendall,

On Mon, Mar 21, 2005 at 03:25:50PM -0500, Kendall Clark wrote:
> On Tue, Feb 01, 2005 at 10:49:04AM -0500, Mark Baker wrote:
> > 
> > Hi,
> > 
> > This comment is submitted jointly by Mark Baker and Jan Algermissen,
> > who discovered they had the exact same concern with the current spec[1].
> Thanks a lot for reading it so carefully.

My pleasure.  It's important work.

> > First, only one concrete protocol is provided (HTTP), which, in our
> > opinion, doesn't exercise the abstract protocol sufficiently to give
> > confidence that it can serve its intended purpose (see our fourth point
> > below too).
> HTTP and SOAP bindings will be provided, eventually.


> > Third, we suggest that its inclusion may affect the interpretation of
> > the concrete protocol.  For example, a SPARQL protocol client may
> > logically invoke GetGraph via HTTP GET and interpret a successful
> > response to mean that GetGraph was invoked, which isn't an
> > interpretation licensed by HTTP, nor reflected in the message in any
> > way.
> In the present and in future drafts (at present, the draft is a bit
> barren of prose), the SparqlGraphRetrieval interface (which is the
> descendant of "GetGraph") may or may not be implemented by service
> providers as they see fit.

I look forward to seeing how that develops.

> > Forth, and related to our first and third points, we believe that
> > concrete protocols developed from the abstract protocol stand a good
> > chance of being architecturally inconsistent with the systems formed
> > by those protocols.  For example, the abstract protocol would seem to
> > suggest that a binding to SOAP would require operations called "Query",
> > "GetGraph", and "GetServiceDescription".  Yet, such an interpretation
> > would be inconsistent with Web architecture when SOAP is used over
> > HTTP.
> This seems more pertinent directed either to the SOAP or TAG folks. At
> any rate, I'm pretty confident that the SOAP binding for SPARQL will
> be sensitive to the issues raised by the WebArch doc -- at least, as
> sensitive as a SOAP binding *can be*.
> In my personal view, not speaking for DAWG now, if there are problems
> beyond that, they are SOAP, not SPARQL problems. But inquiring minds
> may differ, I suppose.

I hear you, and totally understand that position, but respectfully
disagree.  IMO, there's a lot of things - largely architectural - which
are attributed to the SOAP specification which are not, in fact,
licensed by it.

But, without actually having a concrete binding proposal to discuss at
this time, I'm sure you'd agree that it would be hard to have much in
the way of a meaningful conversation on this point.  So, I'm very much
looking forward to a future draft with these bindings, and the
opportunity to comment on them at that time.

> Thanks for yr comments.

My pleasure.  Keep up the good work.

Mark Baker.   Ottawa, Ontario, CANADA.

Received on Monday, 21 March 2005 22:31:24 UTC