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

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
> 
> 
> 
> 
> 
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Received on Monday, 7 May 2007 17:10:43 UTC