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Making progress on graphs

From: Richard Cyganiak <richard@cyganiak.de>
Date: Sun, 13 May 2012 15:59:01 +0100
Message-Id: <842E53D4-3C60-4252-94E3-8EB17A760496@cyganiak.de>
To: RDF Working Group WG <public-rdf-wg@w3.org>

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?

Received on Sunday, 13 May 2012 14:59:32 UTC

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