Re: Issue 1 - ToMultiSet

On 07/07/2016 06:31 AM, james anderson wrote:
> good afternoon;
> 
>> On 2016-07-07, at 14:12, Peter F. Patel-Schneider <pfpschneider@gmail.com
>> <mailto:pfpschneider@gmail.com>> wrote:
>>
>>
>>
>> […]
>> I think that Andy's solution is acceptable as a starting point.
>>
>> It might have been better to have had ToMultiSet in the Graph Pattern column
>> of the table, but even though ToMultiSet is not really a solution modifier and
>> thus should be in the Graph Pattern column.  However, most errata should be
>> about making the smallest change required to fix a problem, and Andy's
>> suggested errata does this.
>>
>> However, Andy's suggested errata is not sufficient because multisets also need
>> to be allowed as Graph Patterns.  Multisets show up in the SPARQL algebra as
>> the translation on inline data and thus need to be accommodated as well.
>>
>>
>> So I suggest
>>
>> Draft:
>>
>> [[
>> query-errata-N:
>>
>> "Section 18.2 Translation to the SPARQL Algebra" intro (end):
>>
>> ToMultiSet can be used where a graph pattern is mentioned below because the
>> outcome of evaluating a graph pattern is a multiset.
>>
>> Multisets of solution mappings are elements of the SPARQL algebra.  Multisets
>> of solution mappings count as graph patterns.
>> ]]
>>
>>
>> I note that this problem does not just affect EXISTS, but affects just about
>> every construct because of the wording
>>
>> P, P1, P2 : graph patterns
>>
>> near the beginning of 18.6.
>>
>> peter
>>
>> PS:  I do note that the translation to the SPARQL algebra is defined in a
>> somewhat sloppy manner that makes it hard to determine exactly what is
>> supposed to result.  I don't think that there are any problems that arise from
>> this sloppiness but the translation needs some attention if there ever is a
>> next version of SPARQL.
>>
> 
> -1
> 
> what is the concrete benefit of the “add a note” approach, when not putting
> the entry in the table puts the reader in the position to need to correlate
> information at different locations in the document?
> 
> best regards, from berlin,
> ---
> james anderson | james@dydra.com <mailto:james@dydra.com> | http://dydra.com

The only benefit is that this is a smaller change.  It does not remove
ToMultiSet from the solution modifiers part of the algebra.

I don't think that there are any negative consequences of the removal.  I
believe that moving ToMultiSet results in a better document.  However, the
SPARQL document is long and complex so I'm not completely sure of the lack of
negative consequences, thus I prefer the smaller change because I see only a
tiny added benefit from making the larger change.

peter

Received on Thursday, 7 July 2016 13:48:29 UTC