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. -Stephen [1] http://www.w3.org/TR/sparql11-query/#neg-example-2 [2] https://repository.apache.org/content/repositories/snapshots/org/apache/jena/jena-fuseki/0.2.4-SNAPSHOT/jena-fuseki-0.2.4-20120703.101036-6-distribution.zip
