I think a query interface as you say is orthogonal to Reto's
impl.sparql module - which is trying to be an implementation of RDF
Commons that is backed only by a remote SPARQL endpoint.  Thus it
touches on important edges like streaming and blank node identities.

It's not a SPARQL endpoint backed by RDF Commons! :-)



On 20 March 2015 at 10:58, Sergio Fernández <[email protected]> wrote:
> Hi Reto,
>
> yes, that was a deliberated decision on early phases. I'd need to look it
> up, I do not remember the concrete issue.
>
> Just going a bit deeper into the topic, in querying we are talking not only
> about providing native support to query Graph instance, but also to provide
> common interfaces to interact with the results.
>
> The idea was to keep the focus on RDF 1.1 concepts before moving to query.
> Personally I'd prefer to keep that scope for the first incubator release,
> and then start to open discussions about such kind of threads. But of course
> we can vote to change that approach.
>
> Cheers,
>
>
>
> On 17/03/15 11:05, Reto Gmür wrote:
>>
>> Hi Sergio,
>>
>> I'm not sure which deliberate decision you are referring to, is it Issue
>> #35 in Github?
>>
>> Anyway, the impl.sparql code is not about extending the API to allow
>> running queries on a graph, in fact the API isn't extended at all. It's an
>> implementation of the API which is backed by a SPARQL endpoint. Very often
>> the triple store doesn't run in the same VM as the client and so it is
>> necessary that implementation of the API speak to a remote triple store.
>> This can use some proprietary protocols or standard SPARQL, this is an
>> implementation for SPARQL and can thus be used against any SPARQL
>> endpoint.
>>
>> Cheers,
>> Reto
>>
>>
>>
>>
>> On Tue, Mar 17, 2015 at 7:41 AM, Sergio Fernández <[email protected]>
>> wrote:
>>
>>> Hi Reto,
>>>
>>> thanks for updating us with the status from Clerezza.
>>>
>>> In the current Commons RDF API we delivery skipped querying for the early
>>> versions.
>>>
>>> Although I'd prefer to keep this approach in the initial steps at ASF (I
>>> hope we can import the code soon...), that's for sure one of the next
>>> points to discuss in the project, where all that experience is valuable.
>>>
>>> Cheers,
>>>
>>> On 16/03/15 13:02, Reto Gmür wrote:
>>>
>>>> Hello,
>>>>
>>>> With the new repository the clerezza rdf commons previously in the
>>>> commons
>>>> sandbox are now at:
>>>>
>>>> https://git-wip-us.apache.org/repos/asf/clerezza-rdf-core.git
>>>>
>>>> I will compare that code with the current status of the code in the
>>>> incubating rdf-commons project in a later mail.
>>>>
>>>> Now I would like to point to your attention a big step forward towards
>>>> CLEREZZA-856. The impl.sparql modules provide an implementation of the
>>>> API
>>>> on top of a SPARQL endpoint. Currently it only supports read access. For
>>>> usage example see the tests in
>>>> /src/test/java/org/apache/commons/rdf/impl/sparql (
>>>> https://git-wip-us.apache.org/repos/asf?p=clerezza-rdf-core.
>>>> git;a=tree;f=impl.sparql/src/test/java/org/apache/commons/
>>>> rdf/impl/sparql;h=cb9c98bcf427452392e74cd162c08ab308359c13;hb=HEAD
>>>> )
>>>>
>>>> The hard part was supporting BlankNodes. The current implementation
>>>> handles
>>>> them correctly even in tricky situations, however the current code is
>>>> not
>>>> optimized for performance yet. As soon as BlankNodes are involved many
>>>> queries have to be sent to the backend. I'm sure some SPARQL wizard
>>>> could
>>>> help making things more efficient.
>>>>
>>>> Since SPARQL is the only standardized methods to query RDF data, I think
>>>> being able to façade an RDF Graph accessible via SPARQL is an important
>>>> usecase for an RDF API, so it would be good to also have an SPARQL
>>>> backed
>>>> implementation of the API proposal in the incubating commons-rdf
>>>> repository.
>>>>
>>>> Cheers,
>>>> Reto
>>>>
>>>>
>>> --
>>> Sergio Fernández
>>> Partner Technology Manager
>>> Redlink GmbH
>>> m: +43 660 2747 925
>>> e: [email protected]
>>> w: http://redlink.co
>>>
>>
>
> --
> Sergio Fernández
> Partner Technology Manager
> Redlink GmbH
> m: +43 660 2747 925
> e: [email protected]
> w: http://redlink.co



-- 
Stian Soiland-Reyes
Apache Taverna (incubating), Apache Commons RDF (incubating)
http://orcid.org/0000-0001-9842-9718

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