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Re: shared bnodes (Skolems, SPARQL)

From: Sandro Hawke <sandro@w3.org>
Date: Wed, 29 Aug 2012 08:15:59 -0400
Message-ID: <503E07FF.4050005@w3.org>
To: Steve Harris <steve.harris@garlik.com>
CC: Andy Seaborne <andy.seaborne@epimorphics.com>, public-rdf-wg@w3.org
On 08/28/2012 11:52 AM, Steve Harris wrote:
> On 2012-08-24, at 16:52, Sandro Hawke wrote:
>
>  snip 
>
>>> And sub/union graphs in general.
>>>
>>> Union graphs for those systems that already make one graph the union of all others.  Whether we like it or not, those systems are common, even maybe even the majority, and have been for several years.
>>>
>>> It is the compromise of the context point-of-view and the multiple-graphs point-of-view.  In the context POV,
>>>
>>> (this is not advocacy, more like 'history')
>>>
>> agreed.
>>
>> To put that slightly differently: shared bnodes are also required for the SPARQL dump & restore use case.
> Yup, that was one of the motivations for Skolem URIs.

How would that work, if there was already Skolmized RDF in the 
dataset?    (And there will be, if your dataset comes from crawling 
other people's data sources, and those data sources emit Skolemized RDF, 
as we're expecting they will sometimes.)

I guess you could make a new Skolem prefix (eg 
http://example.com/.well-known/genid/backup-20120829T081103/) and genid 
your bnodes to new URLs starting with that string -- and then pass that 
string along with the backup file.     But keeping those together might 
be difficult, and if you're going to do that, there's no need for any 
sort of standard format for Skolems.

      -- Sandro
Received on Wednesday, 29 August 2012 12:16:13 UTC

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