On Tue, Jul 3, 2012 at 5:47 PM, Stephen Allen <[email protected]> wrote:
> On Tue, Jul 3, 2012 at 5:08 PM, Rob Vesse <[email protected]> wrote:
>> I've noticed what may be a regression in MINUS behavior but may be wrong.  
>> Long ago one of our developers wrote the following query as a test case:
>>
>>
>> SELECT *
>>
>> WHERE {
>>
>>   ?n0 ?n1 ?n2 .
>>
>>   MINUS { <http://www.cray.com/n0-2> <http://www.cray.com/n1-2> 
>> <http://www.cray.com/n2-2> .}
>>
>> }
>>
>>
>> I.e. They are minusing a concrete triple pattern from some variables, prior 
>> to ARQ 2.9.2 this worked but from 2.9.2 onwards it doesn't (likely because 
>> of Paul Gearon's changes)
>>
>
> I'm not clear on what you mean by "worked".  What do you expect the
> results to be?
>
>>
>> Now I'm not sure if this should ever have worked since the spec says that a 
>> MINUS with no shared variables has no effect.  I only discovered the query 
>> (which was buried away in some Spring context – oh joy!) because bumping the 
>> ARQ version to the 2.9.3-SNAPSHOT to pick up some of mine and Andy's recent 
>> SPARQL TSV improvements caused this test to start failing.
>>
>>
>> What is the expected behavior in this case?
>>
>
> The working draft seems to address this directly [1], you should get
> back all the triples in the default graph (as the MINUS evaluates to
> no bindings and thus no solutions are eliminated from the LHS).
>
>>
>> If this is a regression can someone open a bug and take a look at fixing 
>> this, if this isn't a bug and the new ARQ behavior is actually now correct 
>> let me know as a query like this should be added to the DAWG test suite so 
>> I'll send a formal comment (unless Paul/Andy just want to propose this at 
>> the next WG telecom themselves?)
>>
>>
>
> I tested the example in the working draft against both Fuseki 0.2.3
> (ARQ 2.9.2) and against Fuseki 0.2.4-SNAPSHOT (ARQ 2.9.3-SNAPSHOT) [2]
> and got the results indicated in the spec.
>

Realized you said "prior to ARQ 2.9.2", so I tested against Fuseki
0.2.1-incubating (ARQ 2.9.0) as well, and I get the same results.

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