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Re: SPARQL Endpoint with Inference support

From: Manuel Salvadores <ms8@ecs.soton.ac.uk>
Date: Tue, 28 Sep 2010 09:32:33 +0100
Cc: semantic-web@w3.org
Message-ID: <EMEW3|9def808085b355876b479fe555f61d3dm8R9Xw03ms8|ecs.soton.ac.uk|3331FBC4-5A85-4E28-B987-579C5DD5125D@ecs.soton.ac.uk>
To: Riccardo Tasso <tasso@elet.polimi.it>
Riccardo,

4sr [1] is an extension of 4store [2] that allows you to SPARQL with RDFS entailments.

4sr has a parameter to disable the RDFS reasoning.

When running 4s-query by adding "-n" option.
When running the SPARQL endpoint by adding "no-reasoner=true" in the HTTP request.
There is a short demo at [3].

If your reasoning is at the RDFS level then 4sr might be a good option for you.

Best,

Manuel

[1] http://4sreasoner.ecs.soton.ac.uk/
[2] http://4store.org/ 
[3] http://4sreasoner.ecs.soton.ac.uk/demo.html


On Sep 27, 2010, at 3:19 PM, Andrea Splendiani wrote:

> Yes, you can do that.
> For updates, it may be more tricky.
> 
> In brief:
> 
> In Jena/Joseki you build up a model via a spec file.
> 
> Imagine your data files (the triplestore, not the rdf) are at
> /exampled/dir/data,
> 
> you can build both a plain model which holds /example/dir/data or an an
> infmodel, which has the same data and your choice of reasoners.
> 
> You can plug any of the two into Joseki (mutiple instances on different
> ports)
> 
> Now:
> 
> if you use TDB as a Jena backend, I'm not sure it is safe versus concurrent
> accesses (the two joseki accessing the same files). Not for sure in writing,
> perhaps ok in reading.
> 
> You can use SDB (which is a relational backed triplestore): less performant,
> but should support concurrent R/W access.
> 
> You can find more info on the Jena mailing list. If you check the archieves,
> I recall some message about TDB/SDB and concurrency.
> 
> How big is your data ?
> 
> SDB il less performant than TDB, for big data (well... relatively) this can
> make a difference.
> 
> ciao,
> Andrea
> 
> Il giorno 27/set/2010, alle ore 16.09, Riccardo Tasso ha scritto:
> 
>> Grazie Andrea,
>>    but what if I need to access data from a SPARQL endpoint? Could I
>> use Joseki to query two different models (one inferred, and one
>> "simple") such that they are based on the same data? Please note that
>> I'd like to have the possibility to execute updates too.
>> 
>> Cheers,
>>    Riccardo
>> 
>> On 27/09/2010 15:19, Andrea Splendiani wrote:
>>> Hi,
>>> 
>>> you can also use Jena for this.
>>> You have a choice of reasoners which you can attach to the RDF model, in
>>> your case you can use either a minimal "transitive reasoner" and (bits
> of) a
>>> rule based reasoner. You can select which rules you want to apply, or
> choose
>>> among default configurations.
>>> If you define your own rules, use backward rules.
>>> 
>>> at the SPARQL level, this is completely transparent. But you can change
>>> reasoners dynamically programmatically if you need.
>>> 
>>> ciao,
>>> Andrea
>>> 
>>> Il giorno 22/set/2010, alle ore 12.06, Riccardo Tasso ha scritto:
>>> 
>>> 
>>>> I'm interested in executing SPARQL queries over an endpoint, sometimes
>>>> with reasoning, sometimes without (dynamically). The reasoning task I
>>>> need are RDFS plus owl:sameAs. It is also an interesting question to me,
>>>> wheter a SPARQL query could specify if the results should contain
>>>> inferred triples or not.
>>>> 
>>>> Do you know a triple store, possibly supporting named graphs, suitable
>>>> to my needs?
>>>> 
>>>> Thanks,
>>>>    Riccardo
>>>> 
>>>> 
>>>> 
>>> Andrea Splendiani
>>> Senior Bioinformatics Scientist
>>> Centre for Mathematical and Computational Biology
>>> +44(0)1582 763133 ext 2004
>>> andrea.splendiani@bbsrc.ac.uk
>>> 
>>> 
>>> 
>>> 
>> 
> 
> Andrea Splendiani
> Senior Bioinformatics Scientist
> Centre for Mathematical and Computational Biology
> +44(0)1582 763133 ext 2004
> andrea.splendiani@bbsrc.ac.uk
> 
> 
> 
> 
Received on Tuesday, 28 September 2010 08:35:01 GMT

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