W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > July to September 2010

Re: What we mean by "graph" / Named Graphs in SD

From: Chimezie Ogbuji <ogbujic@ccf.org>
Date: Tue, 20 Jul 2010 21:35:49 -0400
To: "Sandro Hawke" <sandro@w3.org>, "SPARQL Working Group" <public-rdf-dawg@w3.org>
Message-ID: <C86BC735.12826%ogbujic@ccf.org>
See comments below.

On 7/20/10 2:22 PM, "Sandro Hawke" <sandro@w3.org> wrote:
> I wonder if there's a way out of this mess....    I guess we can at
> least clarify it in the SD document, with some warnings.   Anyone
> interesting in us getting away from the misleading term "NamedGraph"?

Actually, I am as well.  I'm not sure if my reservations are the same as
yours, but if we have the following pair in a dataset:

(uri_1, rdfGraph1)

and SPARQL 1.0 is clear that uri_1 does not *directly* identify / denote
rdfGraph1 but some resource that is serialized by an RDF document which -
when parsed - results in rdfGraph1, then it is a mistake to say that
rdfGraph1 is a 'named graph' since uri_1 doesn't denote it, in the same way
that my name 'Chimezie' denotes me.  It probably is the case that calling it
a named graph is most of the cause of the subsequent efforts that have gone
into being very explicit about the fact that the graph URI does not denote
the graph.

> It may seem like it's entrenched in SPARQL 1.0, but this is just
> editorial, as long as it keeps the GRAPH and FROM NAMED keywords, which
> actually seem fine to me.   (I expect we'll have a new RDF Core WG
> working on this issue in a few months; that's when this will really get
> entrenched.  I expect to strongly oppose this misleading use of the term
> "named graph" during that work, if necessary.)

Just my $0.02 but I think that ship has sailed and contemporary RDF
specifications just need to be very clear about the graph uri / graph
indirection in order to directly address the ambiguity that we have
inherited.
 
>..snip.. 
> I wonder if we could agree on a standard name for sense 1, and try to
> use it.   (Or maybe we already did, and I missed it.)

I think the terms 'graph store' and 'dataset' are meant to capture this
sense 1.

-- Chimezie


===================================

P Please consider the environment before printing this e-mail

Cleveland Clinic is ranked one of the top hospitals
in America by U.S.News & World Report (2009).  
Visit us online at http://www.clevelandclinic.org for
a complete listing of our services, staff and
locations.


Confidentiality Note:  This message is intended for use
only by the individual or entity to which it is addressed
and may contain information that is privileged,
confidential, and exempt from disclosure under applicable
law.  If the reader of this message is not the intended
recipient or the employee or agent responsible for
delivering the message to the intended recipient, you are
hereby notified that any dissemination, distribution or
copying of this communication is strictly prohibited.  If
you have received this communication in error,  please
contact the sender immediately and destroy the material in
its entirety, whether electronic or hard copy.  Thank you.
Received on Wednesday, 21 July 2010 01:36:36 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:43 GMT