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Re: Blank Node Identifiers and RDF Dataset Normalization

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Tue, 26 Feb 2013 18:46:43 +0000
Message-ID: <512D0313.5000106@epimorphics.com>
To: public-rdf-wg@w3.org


On 26/02/13 17:53, Kingsley Idehen wrote:
> On 2/26/13 12:46 PM, Andy Seaborne wrote:
>> Jena users find the default graph concept useful:
>>
>> 1/ When there is one graph being published
>
> Yes-ish. I say that because the implications are really obvious.
>
> Imagine if that's how an SQL RDBMS handled the fact that you just wanted
> to have some records created quickly i.e., they had an anonymous default
> table. Likewise, the schema was an anonymous table etc..

That an analogy does not work for me.

Default database in a DBMS is nearer.

>
>>
>> 2/ As the union of the named graphs
>
> But they could also explicitly seek a union of said graphs in a query if
> that's what delivered the solution sought.

Different - that would be the query asking for it, not the publisher 
providing it.

Historical note:

One original usage of graph labelling was "contexts" - labels that 
section up a large graph - where the intent is that there is one graph, 
data-managed in sections.

>
>>
>> 3/ As a single place to put the manifest
>
> That place could have a name by default.

Workable with care.

1/ Your name != my name because your default graph != my default graph.

(so please not rdf:manifestGraph for the name)

2/ Includes the manifest in the union of graphs

3/ Adding a rdf:type to find the manifest then allows several.

Then the manifest is still "special" in some way so it's more of a 
different approach than a unifying solution.

>> Conclusion: you don't have to use it if you don't want to.
>>
>> (all well worn points)
>>
>>     Andy
>
> Yes-ish.
>
> The trouble is that users always use defaults under the misguided
> assumption that defaults know best :-)

On that we agree!  "default" = "a guess".

Also, "default" is often taken to mean "solve my problem" which is not.

>
> Kingsley
>>
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Received on Tuesday, 26 February 2013 18:47:16 GMT

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