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Review of SPARQL Update submisson (ACTION-53)

From: Luke Wilson-Mawer <luke.wilson-mawer@garlik.com>
Date: Mon, 20 Jul 2009 15:45:30 +0100
Message-ID: <4A64830A.1050908@garlik.com>
To: SPARQL Working Group <public-rdf-dawg@w3.org>

Here are my comments on the UPDATE submission, they aren't independent 
since Steve's name is on the submission for Garlik, but hopefully 
they're useful nonetheless


Streaming of large chunks of data seems like something the protocol 
ought to do - it seems to me more natural to squirt a whole file over 
the wire than to turn the data into a query.  The LOAD <remoteURI> 
feature would also seem like a natural way to do this, possibly extended 
to load local files, although I'm not sure about the security consequnces.

2) It doesn't seem clear whether a WHERE clause and FILTERS can be used 
with these verbs:

3) Do we really need the MODIFY verb?  It seems to be syntactic sugar, 
as we can always use either DELETE FROM <uri> or INSERT INTO <uri> to 
specify a graph.  It isn't used in any of the examples but it's 
mentioned elsewhere.  The only thing it seems to do is stop the user 
having to type a graph name more than once if multiple operations are 
done on the same graph in the same query.

4) I agree with Alex Passant that Example 2e would be simplified by 
introducing a MOVE verb.  Still, this example requires the full syntax:

The bookStore2 graph is created and only a year's worth of books are kept :

    PREFIX dc:  <http://purl.org/dc/elements/1.1/>
    PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

    INSERT INTO <http://example/bookStore2>
     { ?book ?p ?v }
      { GRAPH  <http://example/bookStore>
         { ?book dc:date ?date .
           FILTER ( ?date < "2000-01-01T00:00:00"^^xsd:dateTime && ?date
     > "1999-01-01T00:00:00"^^xsd:dateTime)
           ?book ?p ?v

    DELETE FROM <http://example/bookStore>
     { ?book ?p ?v }
      { GRAPH  <http://example/bookStore>
          { ?book dc:date ?date .
            FILTER ( ?date < "2000-01-01T00:00:00"^^xsd:dateTime )
            ?book ?p ?v


Received on Monday, 20 July 2009 14:46:09 UTC

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