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Re: Making progress on graphs

From: Richard Cyganiak <richard@cyganiak.de>
Date: Mon, 14 May 2012 11:49:45 +0100
Cc: RDF Working Group WG <public-rdf-wg@w3.org>
Message-Id: <57D55110-2471-4A6D-9E9A-13E177A345D5@cyganiak.de>
To: Ivan Herman <ivan@w3.org>
Hi Ivan,

On 14 May 2012, at 05:37, Ivan Herman wrote:
>> 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”).
> 
> You are right that these particular issues seem to have general consensus. My concern is that, by taking a formal resolution on this now, we get ourselves into a false sense of security of having solved the named graph issue. And that is not the case or at least there is no consensus that being the case. Hence my reluctance of taking your proposal as a formal step.

This is *exactly* why I listed various open issues that are *not* addressed by the proposal as part of the rationale. I will repeat:

• 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?

My proposal does not touch on any of these questions. This is intentional. All these issues still need to be discussed, worked out, and decided separately.

> For example, Sandro also formally speaks of quads: these are widely used, never defined, and obviously closely related to the issue of named graphs. This is not part of your proposal.

My proposal addresses structure, not terminology. The question whether we introduce some extra terminology like “quads” or give an explicit name to concepts like “a dataset-by-another-name without empty graphs” is not addressed by the proposal. This is intentional.

> I do not think that Sandro's document is 'highly controversial'; it is a much less radical approach than many that was discussed in the past few months.

Sandro's document *is* highly controversial. This thread is sufficient evidence.

> In this in this sense that it is a good basis of discussion (in my view).

Oh, we've had many a great discussion about graphs over the last year, and yes I'm sure Sandro's document can fuel them for a couple more months. But can we maybe have some *decisions* for a change?

At least on the uncontroversial issues?

Best,
Richard
Received on Monday, 14 May 2012 10:50:33 GMT

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