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Re: Draft answer KK-7

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Tue, 01 Mar 2011 20:57:13 +0000
Message-ID: <4D6D5DA9.4020806@epimorphics.com>
To: Axel Polleres <axel.polleres@deri.org>
CC: Lee Feigenbaum <lee@thefigtrees.net>, SPARQL Working Group <public-rdf-dawg@w3.org>


On 01/03/11 10:49, Axel Polleres wrote:
> draft answer is here:
>
> http://www.w3.org/2009/sparql/wiki/CommentResponse:KK-7

It starts:

"""
reuse of bnodes across multiple BGPs in a query may lead to unintuitive 
results:
"""
but Kjetil isn't suggesting it's the same bNode - only that the same 
label can be reused (to mean a different bnode).

Maybe the response could just say that, on balance, the unique label per 
query is felt by the WG to be the clearer approach.

To mutate and add to Lee's words:

"""
There is a balance to be struck between potential confusion due to 
reusing labels to identify different things and the convenience in 
composition of queries.

On balance, the WG believe that the approach of SPARQL 1.0, which avoids 
the confusion possibilities, is the better choice.
"""

	Andy


>
> please let me know if that works for you.
>
> Axel
>
> On 1 Mar 2011, at 01:59, Lee Feigenbaum wrote:
>
>> On 2/28/2011 8:54 PM, Axel Polleres wrote:
>>>
>>> On 1 Mar 2011, at 01:46, Lee Feigenbaum wrote:
>>>
>>>> My personal feeling is that it would be _very_ confusing to allow the
>>>> same bnode label in two BGPs but have it refer to distinct blank nodes.
>>>> You'd have a situation where sometimes (within the same BGP) two
>>>> mentions of _:a would be the same and other times (in two BGPs, perhaps
>>>> separated by BIND or something like that)  they wouldn't.
>>>>
>>>> Please let me know if anyone feels otherwise. If there appears to be
>>>> silence / consensus, then I will draft a response to Kjetil.
>>>
>>> That was my feeling as well, I just thought that this motivation was probably discussed in DAWG1 already s.t.
>>> we can refer to it in the answer.
>>
>> I don't remember specifically discussing the option of allowing the same
>> label in 2 BGPs but having it refer to different blank nodes.
>>
>> Lee
>>
>>>
>>> Axel
>>>
>>>>
>>>> Lee
>>>>
>>>> On 2/28/2011 8:15 PM, Axel Polleres wrote:
>>>>> Hi all,
>>>>>
>>>>> in order to answer comment KK-7
>>>>>     http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2011Jan/0009.html
>>>>>
>>>>> I am pretty sure that this has been discussed in depth and there is some DAWG1-discussion
>>>>> about this issue somewhere back in the archives... If anybody from our DAWG1 members
>>>>> feels like pointing me to it, I'd be grateful!
>>>>>
>>>>> Axel
>>>>>
>>>>
>>>
>>>
>>
>
>
Received on Tuesday, 1 March 2011 20:57:52 GMT

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