Re: [namedgraphs] [Fwd: Re: Problem related to Jena 2.6.0]

[Riccardo T. <ta...@el...>]

I'm using NG4J for this task:

* I have n RDF sources containing statements about many entities (e.g. 
name, email, SN);
* each source has a provenance, a date and a trust value, that's why I 
represent each one of them with a Named Graph;
* some sources may contain the same entities but with different URIs 
(e.g. John Smith in data source 1 is ds1:person1 but in data source 2 is 
ds2:person 47);
* I create a default graph containing only assertion such as:
        <default:person2, owl:sameAs, ds1:person1>
        <default:person2, owl:sameAs, ds1:person1>
* this match is performed by the key value of each entity (e.g. SN);
* if two data sources say something contraddictory (e.g. the same person 
has different salaries) I would like to perform queries such has:
       which is the salary of this person by the source with the highest 
trust value;
       which is the salary of this person by the most recent source;
       how many datasources state that this person has this salary;

Hence I need a model containing all the data from each datasource plus 
the default graph with a reasoner capable to infer owl:sameAs 
relationship without loosing the provenance of each triple.
Do you think NG4J is good for this task? I thought to try it because I 
didn't know about Jena TDB. Could anyone go into more depth about the 
different approaches?

Thanks,
    Riccardo

Jennifer Cormier ha scritto:
> I remember looking into the "named graphs" feature of the Jena TDB release
> last year.  Based on what I recall, it was quite different from NG4J's
> implementation.  Individual graphs are stored separately and must be
> loaded individually.
>
> In the NG4J implementation, a quad store is used so that each triple is
> associated with a 4th item, that being the graph name.  It is possible to
> search using SPARQL over an entire dataset, across graphs, and get only
> those quads of interest, whether or not they are in the same graph.
>
> It's possible that Jena offers another type of "named graph" support, or
> that I misremember the details.  This is based upon my recollection.
>
>
> Jennifer
>
>
> -----Original Message-----
> From: tim...@go... [mailto:tim...@go...] On Behalf
> Of Tim Pizey
> Sent: Tuesday, January 12, 2010 11:10 AM
> To: Riccardo Tasso; jen...@at...;
> ng4...@li...
> Subject: Re: [Fwd: Re: [namedgraphs] Problem related to Jena 2.6.0]
>
> Hi Riccardo,
>
> It should be a relatively straight-forward thing to update to the latest
> jena.
>
> I would ask what is the functionality in ng4j that you want to use?
>
> ng4j has an assortment of features, only one of which is named graphs.
>
> My understanding is that the named graphs features have been
> re-implemented within jena itself.
>
> yours
> Tim Pizey
>
> 2010/1/12 Riccardo Tasso <ta...@el...>:
>   
>> -------- Messaggio Originale --------
>> Oggetto:        Re: [namedgraphs] Problem related to Jena 2.6.0
>> Data:   Tue, 12 Jan 2010 16:35:09 +0100
>> Da:     Riccardo Tasso <ta...@el...>
>> A:      Jennifer Cormier <jen...@at...>
>> CC:     ng4...@li..., 'Tim Pizey'
>> <tim...@ou...>
>> Referenze:      <4B4...@el...>
>> <00e901ca92ee$93f48db0$7801a8c0@ATC73>
>>
>>
>>
>> Thank you Jennifer,
>>  I'm really interested in the possibilities which named graphs could
>>     
> offer
>   
>> to my project. In the next days I'll try to import in Eclipse the NG4J
>> source and to update Jena libraries to see if it's immediate. Then I'll
>>     
> make
>   
>> you know my results.
>>
>> Riccardo
>>
>> Jennifer Cormier ha scritto:
>>     
>>> Hi Riccardo,
>>>
>>> It's great to hear you are using to NG4J!  Sorry that its version of
>>>       
> Jena
>   
>>> seems to be causing problems.
>>>
>>> Last summer Tim Pizey had NG4J working locally against a
>>> pre-Jena-2.6.2-snapshot.  I don't know whether anyone has worked on
>>>       
> that
>   
>>> since.
>>>
>>> Tim?  Anyone?
>>>
>>>
>>> Jennifer
>>>
>>> -----Original Message-----
>>> From: Riccardo Tasso [mailto:ta...@el...] Sent: Monday,
>>>       
> January
>   
>>> 11, 2010 8:47 AM
>>> To: ng4...@li...
>>> Subject: [namedgraphs] Problem related to Jena 2.6.0
>>>
>>> Hi everybody,
>>>    I'm starting a project using NG4J and I'm currently using the
>>>       
> lastest
>   
>>> version (0.9.2) which is based on Jena 2.6.0. In these days I tried to
>>> validate a RDF dataset with a RDF Schema but it gives me problems with
>>>       
> Jena
>   
>>> 2.6.0 but it works ok with Jena 2.6.2. Is it possible to update the
>>>       
> NG4J
>   
>>> making it use Jena 2.6.0?
>>>
>>> If you like I could get more specific about my problem, but I'm pretty
>>> sure it regards more Jena than NG4J.
>>>
>>> Thanks,
>>>    Riccardo
>>>
>>>
>>>       
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>>
>>