Re: Implementation feasibility

On Fri, Mar 20, 2015 at 8:10 PM, Jose Emilio Labra Gayo <jelabra@gmail.com>
wrote:

> On Fri, Mar 20, 2015 at 6:52 PM, Peter F. Patel-Schneider <
> pfpschneider@gmail.com> wrote:
>
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>> On 03/20/2015 10:48 AM, Jose Emilio Labra Gayo wrote:
>> > On Fri, Mar 20, 2015 at 5:54 PM, Dimitris Kontokostas
>> > <kontokostas@informatik.uni-leipzig.de
>> > <mailto:kontokostas@informatik.uni-leipzig.de>> wrote:
>>
>> [...]
>>
>> >
>> > Holger, you only mention SPARQL based implementations...this contradicts
>> > the assertion that it will be possible to have non-sparql based
>> > implementations.
>> >
>> > At this moment, there are already some implementations that show that
>> > non-SPARQL based implementations of the core language are feasible.
>>
>> Are there any correct implementations of the core language, i.e., roughly
>> what is described in http://w3c.github.io/data-shapes/data-shapes-primer/
>> ?
>>
>
> There are several implementations for ShEx, which is a similar language to
> the one described there.
>
>> How well do they work on large RDF graphs?
>>
>
> It depends on what you call "large RDF graphs" and on what you call "work
> well". Some of the work has been done precisely to identify tractable
> subsets of the language. Much more work can be done to find better
> algorithms and optimizations and even to define hybrid implementation that
> leverage parts of the implementation to other tools.
>

What about DBpedia? Around 3B triples in the last release and we expect a
big increase in the next one.
http://www.slideshare.net/jimkont/dbpedia-dublin-aligned-1


> As an example, my ShExcala implementation contained a "validation by
> endpoint" extension which allows triples that affect a node to be validated
> on demand through an endpoint. This was an experimental feature that I had
> no time to fully test due to other obligations. I also think Eric has also
> been working extending his implementation in a similar way.
>

Correct me if I am wrong but IIRC your implementation was just running ShEx
on the results of a SPARQL CONSTRUCT query which is more like validating a
remote RDF file.


> The WG can promote the appearance of independent implementations which do
> not depend on SPARQL or it can prohibit them by saying that in order to
> implement SHACL one needs a SPARQL engine.
>

So far I didn't hear any WG members in favor of SPARQL object in having a
'SHACL part' (call it whatever) that can be implemented independent of
SPARQL

Best,
Dimitris

>
> Best regards, Jose Labra
>
>
>
>>
>> peter
>>
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>
>
>
> --
> -- Jose Labra
>
>


-- 
Dimitris Kontokostas
Department of Computer Science, University of Leipzig
Research Group: http://aksw.org
Homepage:http://aksw.org/DimitrisKontokostas