Re: ACTION: discuss & promote union query (Was: ACTION: a replacement for 4.5 focussed on union query)

On Tue, Aug 24, 2004 at 05:59:20PM +0100, Steve Harris wrote:
> OK, so I have an agregator (a single store containing multiple RDF files,
> to be clear), now how do I query it without loosing the source
> information?

Indeed. And since there is an entire class of applications which
essentially just *are* graph aggregators (a single web resource
containing triples from multiple RDF source graphs) that users want to
query, how can those apps be DAWG apps w/out some kind of source
feature, even if it's optional?

> I think you will find that a sustantial number of RDF stores keep and use
> SOURCE information.

Yes. rdflib does. *All* of our SW applications use SOURCE
information. We're effectively out of the game w/out it, I fear. And I
think that we are -- as much as people don't like it, including me --
fairly representative of a consequential early adopter of this
technology, namely, "intelligence community" users. Being able to
query more than one graph and to be able to tell which triples came
from which graph (in the common case; inference is, admittedly, a
complication  -- but, hell, it's one we've deferred *ruthlessly*).

> The queries tend to be fairly trivial ("I need to refresh all the files
> written by John", "What file says that my name is '$firstname $surname'")
> but they are important.

Yes. Except, well, more crucial than "important" in many cases. :>

If SOURCE isn't a query language issue, then what is it? How do I
provide the same functionality to users treating it as a protocol
thing? The same people who are saying it *is* protocol also oppose any
kind of aggregate, union, or federated query.

Kendall Clark

Received on Tuesday, 24 August 2004 17:12:02 UTC