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From Enrico Daga <enricod...@gmail.com>
Subject Re: clerezza-virtuoso storage adapter
Date Wed, 16 Nov 2011 17:41:48 GMT
On 16 November 2011 00:14, Tommaso Teofili <tommaso.teofili@gmail.com> wrote:
> 2011/11/15 Enrico Daga <enricodaga@gmail.com>
>
>> Hi Reto,
>> sorry for this late reaction (and sorry to the clerezza-dev list!) but
>> I missed this e-mail...
>> The reason for implementing this adapter was that we use Virtuoso Open
>> Source as quad store for http://data.cnr.it and I am working on the
>> integration of some Stanbol components (in particular Reasoners and
>> Ontonet) with it. So, my aim was simply to have Stanbol/Clerezza
>> read/write on virtuoso. I preferred to write a light jdbc-based
>> adapter instead of using the sesame based library shipped with
>> virtuoso (and having yet another intermediate layer...). For this I
>> have learned a lot from the implementation of the weighted provider
>> for Sesame (I have totally cloned the multithread tests, for
>> instance...;) ).
>> I didn't do a comparison with Jena TDB in terms of performances and
>> scalability, but data.cnr.it started with virtuoso and we like it (it
>> hosts more then 2.700.000 triples and is very fast on a 2G virtual
>> machine...).
>> Now I am working on long term operations for stanbol reasoners, after
>> that I will start working on stanbol+data.cnr.it via clerezza-virtuoso
>> and have a *real* test for that component.
>>
>> If the Clerezza community likes it, I would be very happy to
>> contribute that code to the project.
>>
>
> in my opinion this would be a very valuable contribution as I have seen
> Virtuoso being used with huge storage scenarios as well.
> Also from a community development point of view it could ease the Clerezza
> adoption for Virtuoso users.
> BUT I think that's not possible at the moment due to licensing issues wich
> GPL2, see [1][2].
> Am I wrong?
The GPL license applies to the virtuoso open source released code, it
seems it can be ignored if the only dependency is on external
libraries, like the jdbc driver (which is our case).
I read from [1]:
[...]
Client Protocol Driver exemptions

    In addition, as a special exemption, OpenLink Software gives
    permission to use the unmodified client libraries (ODBC, JDBC,
    ADO.NET, OleDB, Jena, Sesame and Redland providers) in your own
    application whether open-source or not, with no obligation to use
    the GPL on the resulting application. In all other respects you
    must abide by the terms of the GPL.
[...]

But of course I suggest to write to OpenLink asking explicitly if this
is valid also for distribution, since we should embed the jar in the
module, as it is now (AFAIK there is no maven artifact available to
download, but I could be wrong...)

cheers
Enrico
> Tommaso
>
> [1] : http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VOSLicense
> [2] : http://www.apache.org/legal/resolved.html
>
>
>>
>> (Last but not least, code reviews or any hint on the implementation is
>> welcome!)
>>
>> Bests,
>> Enrico
>>
>> On 10 November 2011 23:48, Reto Bachmann-Gmür <reto@apache.org> wrote:
>> > Enrico wrote:
>> >>
>> >> progress:
>> >> - implemented clerezza-virtuoso storage adapter  (stanbol -
>> >> data.cnr.it integration)
>> >>
>> >>
>> >>
>> >>
>> >>
>> https://github.com/enridaga/clerezza-virtuoso/tree/master/clerezza-virtuoso
>> >
>> > Hi Enrico,
>> >
>> > This looks very cool!
>> >
>> > What are your expiriences, what are the benefits and trade-offs compared
>> > with tdb storage?
>> >
>> > Cheers,
>> > Reto
>> >
>> >
>> >
>> >
>>
>>
>>
>> --
>> Enrico Daga
>>
>> --
>> http://www.enridaga.net
>> skype: enri-pan
>>
>



-- 
Enrico Daga

--
http://www.enridaga.net
skype: enri-pan

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