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Re: Union operations on graphs

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Tue, 7 Feb 2017 13:39:36 -0800
To: Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>
Cc: Holger Knublauch <holger@topquadrant.com>, "public-rdf-shapes@w3.org" <public-rdf-shapes@w3.org>
Message-ID: <d4bb841b-8c26-26b8-cb3f-2109e47f1f2b@gmail.com>
The current wording the document is satisfactory on this particular problem.

peter


On 09/25/2016 05:45 AM, Dimitris Kontokostas wrote:
> Thanks for the suggestion, it is added here
> <https://github.com/w3c/data-shapes/commit/c3623aa6b5b4809b4eb2df3b0be32650b2dd7646>.
> 
> On Sun, Sep 25, 2016 at 1:10 AM, Peter F. Patel-Schneider
> <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote:
> 
>     This is getting better.
> 
>     However, it still appears possible that running a SHACL processor in an RDF
>     store could change the proto-shape graph or the proto-data graph.   I expected
>     wording something like:
> 
>     SHACL processors MUST NOT change the graphs that they use to construct the
>     shapes graph or the data graph, even if these graphs are part of an RDF store
>     that allows changes to its stored graphs.  SHACL processors MAY store the
>     graphs that they create, such as a graph containing validation results, and
>     this operation MAY change existing graphs in an RDF store, but not any of the
>     graphs that were used to construct the shapes graph or the data graph.  SHACL
>     processing is thus idempotent.
> 
> 
>     peter
> 
> 
> 
>     On 09/24/2016 06:53 AM, Dimitris Kontokostas wrote:
>     > Hi Peter and thank you for your feedback
>     >
>     > I tried to work further on this here
>     >
>     <https://github.com/w3c/data-shapes/commit/339b655f82463161b954684ea205b3c67fb483e8
>     <https://github.com/w3c/data-shapes/commit/339b655f82463161b954684ea205b3c67fb483e8>>,
>     > let me know if this resolves the issue.
>     >
>     > Thanks,
>     > Dimitris
>     >
>     > On Friday, September 23, 2016, Holger Knublauch <holger@topquadrant.com
>     <mailto:holger@topquadrant.com>
>     > <mailto:holger@topquadrant.com <mailto:holger@topquadrant.com>>> wrote:
>     >
>     >     On 23/09/2016 11:36, Peter F. Patel-Schneider wrote:
>     >
>     >
>     >             union operations on data graphs and shapes graphs
>     >
>     >             It is unclear just what the data graph and the shapes graph are.
>     >             There is
>     >
>     >         wording that both of these cannot be changed. However, there is also
>     >         wording
>     >         that various kinds of union operations are to be performed on
>     shapes and
>     >         data graphs.
>     >
>     >                  Comment (HK): The only place I could find "union" was about
>     >             handling
>     >
>     >         of owl:imports, which states that the result of this union is
>     used as
>     >         shapes
>     >         graph. This looks OK to me. Could you clarify what you mean?
>     >
>     >                  Comment (DK): I tried to make the wording clearer here:
>     >
>     >       
>      https://github.com/w3c/data-shapes/commit/b6fd2db5719cc9c9bdec464acdd2aefc8d0b5b68
>     <https://github.com/w3c/data-shapes/commit/b6fd2db5719cc9c9bdec464acdd2aefc8d0b5b68>
>     >       
>      <https://github.com/w3c/data-shapes/commit/b6fd2db5719cc9c9bdec464acdd2aefc8d0b5b68
>     <https://github.com/w3c/data-shapes/commit/b6fd2db5719cc9c9bdec464acdd2aefc8d0b5b68>>
>     >
>     >         I don't find this much better.  If the shapes graph and the data
>     graph
>     >         cannot be changed then there should not be wording about unioning,
>     >         extending, or otherwise modifying the shapes graph or the data
>     graph.
>     >
>     >
>     >     Dimitris, do you have time to revise this further? I guess we need
>     to find
>     >     a different term than "shapes graph" for the originally supplied graph.
>     >     The real shapes graph may be the one that is the output of the
>     transitive
>     >     closure process.
>     >
>     >     Thanks
>     >     Holger
>     >
> 
> 
> 
> 
> -- 
> Dimitris Kontokostas
> Department of Computer Science, University of Leipzig & DBpedia Association
> Projects: http://dbpedia.org, http://rdfunit.aksw.org, http://aligned-project.eu
> Homepage: http://aksw.org/DimitrisKontokostas
> Research Group: AKSW/KILT http://aksw.org/Groups/KILT
> 
Received on Tuesday, 7 February 2017 23:12:08 UTC

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