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[CLOSED] Re: No way to specify an RDF dataset of all the known named graphs

From: Lee Feigenbaum <feigenbl@us.ibm.com>
Date: Mon, 7 May 2007 11:10:37 -0600
To: ogbujic@ccf.org
Cc: public-rdf-dawg-comments@w3.org
Message-ID: <OF5CF9924C.F62598DB-ON872572D4.005E0B68-872572D4.005E5B58@us.ibm.com>

Hi Chimezie,

The working group considered this issue and decided not to make any change 
at this time. 

For the record, you are now a member of the working group and have 
indicated that you are satisfied with us closing this issue, so I am 
marking this thread closed.

thanks,
Lee


Chimezie Ogbuji wrote on 04/04/2007 03:05:38 PM:

> 
> This was discussed in #swig
> (http://chatlogs.planetrdf.com/swig/2007-04-03.html#T20-38-01)
> 
> SPARQL currently does not provide an unambiguous way to specify a
> dataset which corresponds to all the known named graphs.  The only way
> this can be done is to leave out FROM <..> and FROM NAMED <..>
> directives in the prolog (and from the protocol, for SPARQL services).
> The corresponding dataset in this case depends on the host application -
> not very consistent. The only other alternative is to explicitly
> enumerate the known universe in the prolog:
> 
> FROM NAMED G1
> FROM NAMED G2
> ...
> FROM NAMED GN
> 
> This is not practical for a dynamic dataset.
> 
> There is plenty of value in querying against the known universe
> consistently especially for applications which make use of a dataset as
> a named graph partition that can grow indefinitely.  Consider XPath
> 2.0 / XQuery 1.0 which supports querying a collection of XML documents
> without having to explicitly enumerate all the XML documents in the
> collection.
> 
> This is a very useful 'database-wide' query pattern which is well
> supported in document-management languages but not supported in SPARQL
> without assuming the implementation will consistently supply the dataset
> corresponding to all the known named graphs in persistence in the
> absence of any dataset directives in the prolog or at the protocol
> level.
> 
> Other than OWA or CWA issues, I don't see why an explicit syntax for
> binding to such a dataset is not supported by SPARQL to provide a
> consistent way for applications to dispatch these kinds of queries.
> Such a syntax was suggested in the above conversation:
> 
> FROM NAMED *
> 
> [1] http://www.w3.org/TR/xquery-semantics/#sec_fn_doc_collection
> 
> -- 
> Chimezie Ogbuji
> Lead Systems Analyst
> Thoracic and Cardiovascular Surgery
> Cleveland Clinic Foundation
> 9500 Euclid Avenue/ W26
> Cleveland, Ohio 44195
> Office: (216)444-8593
> ogbujic@ccf.org
> 
> 
> 
> 
> 
> 
> Cleveland Clinic is ranked one of the top 3 hospitals in
> America by U.S.News & World Report. Visit us online at
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> 
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Received on Monday, 7 May 2007 17:10:43 GMT

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