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Re: Extending SPARQL XML result format

From: Gregory Williams <greg@evilfunhouse.com>
Date: Mon, 9 Jul 2018 13:36:36 -0400
Cc: Olivier Rossel <olivier.rossel@gmail.com>, Martynas Jusevičius <martynas@atomgraph.com>, public-sparql-dev@w3.org
Message-Id: <475DD9B2-C15D-487D-9C6D-DDD724845116@evilfunhouse.com>
To: Thomas Francart <thomas.francart@sparna.fr>
FWIW, the hacky but standards compliant way I’ve dealt with this in the past is by using the link element with a data: URI.

.greg

> On Jul 9, 2018, at 10:10 AM, Thomas Francart <thomas.francart@sparna.fr> wrote:
> 
> Hello
> 
> Thanks for your answers, here is slightly more extended description of the use-case : I am preparing a "SPARQL query mediator", that is a SPARQL-compatible service that will send the same query to multiple sources and aggregate the results into a single resultset. It can also articulate part of the query with other datasources (like if the SERVICE keyword was used). This involves preprocessings on the query, and post-processing on the result sets.
> I would like the SPARQL client to know if one of the source has reached a LIMIT number of results (I plan to limit the number of results to X for each source)
> I was also thinking about proving the "explain" of the query processing if the SPARQL client asked for it (which sources were queried, how the query got transformed, etc;)
> So the information could be pretty structured and does not seem to fit well in HTTP headers.
> 
> Thanks for your ideas. I might try parsing with additionnal XML elements and let you know.
> 
> Best Regards
> Thomas
> 
> 
> 2018-07-09 13:56 GMT+02:00 Olivier Rossel <olivier.rossel@gmail.com>:
>> Can't the HTTP headers contain such informations, instead of the XML resultSet ?
>> 
>>> Le lun. 9 juil. 2018 à 13:38, Martynas Jusevičius <martynas@atomgraph.com> a écrit :
>>> Have you tried parsing?
>>> 
>>> I think if you used XML elements in your own namespace, it should not
>>> be a problem.
>>> 
>>> But probably better to start by explaining what your use case is,
>>> rather than the solution you think you need.
>>> 
>>> On Mon, Jul 9, 2018 at 1:31 PM, Thomas Francart
>>> <thomas.francart@sparna.fr> wrote:
>>> > Hello
>>> >
>>> > I would like to extend a SPARQL XML result format with custom header
>>> > information; such as query execution time, warning if a search limit was
>>> > reached during query execution, or other king of meta-information about the
>>> > resultset.
>>> >
>>> > From the definition of the SPARQL XML result format at
>>> > https://www.w3.org/TR/rdf-sparql-XMLres/#schemas, I don't see the XML schema
>>> > allows this; there is no extension point. Could someone confirm ?
>>> >
>>> > In practice, would it be possible to have something like :
>>> >
>>> > <?xml version="1.0"?>
>>> > <sparql xmlns="http://www.w3.org/2005/sparql-results#">
>>> >
>>> >   <meta>
>>> >
>>> >     <!-- here put some meta information -->
>>> >
>>> >   </meta>
>>> >
>>> >
>>> >   <head>
>>> >
>>> >     ...
>>> >
>>> >   </head>
>>> >
>>> >   <results>
>>> >     ...
>>> >   </results>
>>> >
>>> > </sparql>
>>> >
>>> >
>>> >
>>> > Would SPARQL result parsers choke on this ? RDF4J ? Jena ?
>>> > Is anyone already using this technique ?
>>> >
>>> > Thanks
>>> > Thomas
>>> >
>>> > --
>>> >
>>> > Thomas Francart - SPARNA
>>> > Web de données | Architecture de l'information | Accès aux connaissances
>>> > blog : blog.sparna.fr, site : sparna.fr, linkedin :
>>> > fr.linkedin.com/in/thomasfrancart
>>> > tel :  +33 (0)6.71.11.25.97, skype : francartthomas
>>> 
> 
> 
> 
> -- 
> 
> Thomas Francart - SPARNA
> Web de données | Architecture de l'information | Accès aux connaissances
> blog : blog.sparna.fr, site : sparna.fr, linkedin : fr.linkedin.com/in/thomasfrancart
> tel :  +33 (0)6.71.11.25.97, skype : francartthomas
Received on Monday, 9 July 2018 17:37:04 UTC

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