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Re: SPARQL Update feature

From: Steve Harris <steve.harris@garlik.com>
Date: Tue, 13 Jul 2010 14:42:01 +0100
Cc: Alexandre Passant <alexandre.passant@deri.org>, SPARQL Working Group <public-rdf-dawg@w3.org>
Message-Id: <719A6AEF-5669-450B-979C-B9D512D1742C@garlik.com>
To: Andy Seaborne <andy.seaborne@talis.com>
On 2010-07-13, at 14:39, Andy Seaborne wrote:
> 
> On 13/07/2010 1:25 PM, Steve Harris wrote:
>> On 2010-07-13, at 11:46, Alexandre Passant wrote:
>> 
>> [ snip, all looks good to me ]
>> 
>>> We initially thought that ALL includes also the default graph, but that will be a problem for removing all named graphs but not the default one (not sure that will happen so often, yet)
>>> So better to have ALL = all named graphs, which leads to the following to clean the store
>>> 
>>> DROP ALL
>>> DROP DEFAULT
>>> 
>>> or
>>> 
>>> DROP ALL
>>> CLEAR DEFAULT
>>> 
>>> What do you think ?
>> 
>> I prefer DROP/CLEAR ALL does everything, including the default graph. "ALL" implies that to me.
> 
> I'm comfortable with that.
> 
> Another possibility for completeness: a special form like
> 
> RESET STORE
> 
> that then puts it outside the issue of whether ALL is all named graphs or all graphs.

Yup. That works.

>> If I really want to leave the named graph, and CLEAR the others I can do that with:
>> 
>> DELETE WHERE { GRAPH ?g { ?x ?y ?z } }
>> 
>> Admittedly there's no DROP equivalent, for graphs that don't do empty graph culling, but that's well into corner cases AFAIC.
> 
> It's not a corner case for me - some implementations are quite happy with empty graphs and they don't naturally get culled.  Such grah stores are a collection of graphs, not stored in a common quad table.

The corner case is that, plus you want to leave the anonymous graph.

>> Otherwise, you could add a "GRAPH *" like syntax, meaning all named graphs, but I predict that users would confuse GRAPH * and ALL a lot.
> 
> Maybe - I'm more comfortable with DROP GRAPH *. With an explicit use of GRAPH, and DEFAULT (not GRAPH DEAFULT) it makes sense and is explainable.  At least "DROP GRAPH *" does not destroy data that the user didn't want addressed.

I don't follow this, but I'm really not that bothered :)

- Steve

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Received on Tuesday, 13 July 2010 13:42:37 GMT

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