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Re: Making progress on graphs

From: Sandro Hawke <sandro@w3.org>
Date: Sun, 13 May 2012 14:15:47 -0400
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
Cc: RDF Working Group WG <public-rdf-wg@w3.org>
Message-ID: <1336932947.3256.73.camel@waldron>
On Sun, 2012-05-13 at 13:36 -0400, Peter F. Patel-Schneider wrote:
> The syntax part of Sandro's document appears mostly fine to me.

Great.

> However, there is quite a bit more to Sandro's document than there is to 
> Richard's proposal.  I'm not in favour of the semantics and

As long as an RDF graph has truth conditions, I think a Dataset also has
to have truth conditions.   Do you agree with that?

I'm trying to get the use cases/example fleshed out enough that we can
see whether/how it breaks if we change/remove the dataset truth
conditions.  I'm not there yet.

>  folding sections.

Yeah, I'll be curious to hear where people fall on this one.  It strikes
me at the kind of thing that some people will really want, and some
people will find silly and useless.   My own inclination is to err on
the side of us doing it, so we can do it pretty well, rather than having
everyone who thinks they need it re-inventing it.

> Given that union dataset and merge dataset don't appear anywhere in the 
> document besides their definitions, I'm not sure what good they are.

Yeah -- I have something else in mind to say about them, but if that
doesn't get said, then I agree that text doesn't really belong.

   - Sandro

> peter
> 
> 
> On 05/13/2012 12:22 PM, Sandro Hawke wrote:
> > On Sun, 2012-05-13 at 17:15 +0200, Ivan Herman wrote:
> >> Richard,
> >>
> >> it looks to me that Sandro's draft document:
> >>
> >> https://dvcs.w3.org/hg/rdf/raw-file/d96c16480e42/rdf-spaces/index.html
> > Please use the "latest version" link -- I'll probably make improvements
> > before some folks look at it:
> >
> > http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-spaces/index.html#
> >
> >> would be a good way to 'settle' things (see [1]), too. At the moment it seems to collect all the various issues that we have discussed with a fairly clear way of moving forward.
> > Yeah, I'm pretty happy with it.  At this point, I'm focusing on the use
> > case/example to try to gain confidence (for myself and others) that it's
> > good, and understand better how to explain it.
> >
> >     -- Sandro
> >
> >> Ivan
> >>
> >>
> >> [1] http://lists.w3.org/Archives/Public/public-rdf-wg/2012May/0178.html
> >>
> >>
> >> On May 13, 2012, at 16:59 , Richard Cyganiak wrote:
> >>
> >>> All,
> >>>
> >>> We've been talking our way up and down the design space for multigraphs for a year now, with not much to show for it. We still have not settled on a basic design.
> >>>
> >>> Once we do settle on a basic design, the real work only starts since we need to nail down the details. This will take time. Our charter says that all documents should go to LC *this month*, and obviously we are nowhere near ready for this.
> >>>
> >>> So I think it's time to stop exploring the design space, and start collapsing it by making decisions.
> >>>
> >>> Obviously there is still strong disagreement on many things when it comes to multigraphs, but it seems to me that all proposals on the table accept a basic *abstract syntax* that is quite similar to the RDF datasets in SPARQL, and even the most adventurous experiments don't really stray from that forumla. Therefore:
> >>>
> >>>
> >>> PROPOSAL: The abstract syntax for working with multiple graphs in RDF consists of a default graph and zero or more pairs of IRI and graph. This resolves ISSUE-5 (“no”), ISSUE-22 (“yes”), ISSUE-28 (“no”), ISSUE-29 (“yes”), ISSUE-30 (“they are isomorphic”), ISSUE-33 (“no”).
> >>>
> >>>
> >>> RATIONALE: All proposals on the table are based on an abstract syntax very similar to SPARQL's notion of an RDF dataset, although there is no consensus on the semantics and the terminology. Making a decision on the basic abstract syntax would unblock the work, and allow various strands of required detail work to proceed independently, hopefully leading to additional resolutions to remaining questions, such as:
> >>>
> >>>   • What's the formal semantics of the abstract syntax?
> >>>   • Definition of the concrete syntaxes (N-Quads, etc.)
> >>>   • Describing how to work with this in the Primer
> >>>   • What do call the pairs? “Named graphs” or something else?
> >>>   • What to call the entire thing? “RDF dataset” or something else?
> >>>   • Can blank nodes be shared among graphs?
> >>>   • What additional terminology (rdf:Graph etc) needs to be defined?
> >>>
> >>> Best,
> >>> Richard
> >>
> >> ----
> >> Ivan Herman, W3C Semantic Web Activity Lead
> >> Home: http://www.w3.org/People/Ivan/
> >> mobile: +31-641044153
> >> FOAF: http://www.ivan-herman.net/foaf.rdf
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >
> >
> 
Received on Sunday, 13 May 2012 18:15:57 GMT

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