Here is a simple test. Remove PathRetractionStrategy from TinkerGraph traversal and see what you get? Do you get what Sqlg returns or the same as if with PathRetractionStrategy.
E.g. graph = TinkerFactory.createModern(); g = graph.traversal().withoutStrategies(PathRetractionStrategy.class); g.V().the().traversal().to().test() If you get the same answer without PathRetractionStrategy, then you know that Sqlg is bugged. HTH, Marko. http://markorodriguez.com > On Oct 24, 2016, at 2:21 PM, pieter-gmail <pieter.mar...@gmail.com> wrote: > > Ok apologies. I thought I spotted the difference and simplified the > gremlin too much to highlight what I thought I saw. The above mentioned > queries are returning the same result in Sqlg as TinkerGraph. > > Here is what is not working. > > final TinkerGraph g = TinkerFactory.createModern(); > GraphTraversal<Vertex, Map<Vertex, Collection<Vertex>>> > traversal = g.traversal() > .V().as("a") > .repeat(both()).times(3).emit().as("b") > .<Vertex, Collection<Vertex>>group().by(select("a")); > printTraversalForm(traversal); > while (traversal.hasNext()) { > Map<Vertex, Collection<Vertex>> vertexMap = traversal.next(); > for (Vertex vertex : vertexMap.keySet()) { > Collection<Vertex> coll = vertexMap.get(vertex); > System.out.println("key: " + vertex.value("name") + ", > value: " + coll.size()); > } > } > > For this Sqlg has the same result as TinkerGraph. > > TinkerGraph > > post-strategy:[TinkerGraphStep(vertex,[])@[a], > RepeatStep([VertexStep(BOTH,vertex), > RepeatEndStep],until(loops(3)),emit(true))@[b], > GroupStep([SelectOneStep(a), NoOpBarrierStep(2500)],[FoldStep])] > > Sqlg > > post-strategy:[SqlgGraphStepCompiled(vertex,[])@[sqlgPathFakeLabel], > GroupStep([SelectOneStep(a)],[FoldStep])] > > key: marko, value: 27 > key: vadas, value: 11 > key: lop, value: 27 > key: josh, value: 27 > key: ripple, value: 11 > key: peter, value: 11 > > Adding in the extra by() > > final TinkerGraph g = TinkerFactory.createModern(); > GraphTraversal<Vertex, Map<Vertex, Collection<Vertex>>> > traversal = g.traversal() > .V().as("a") > .repeat(both()).times(3).emit().as("b") > .<Vertex, Collection<Vertex>>group().by(select("a")) > .by(select("b").dedup().order().by(T.id).fold()); > printTraversalForm(traversal); > while (traversal.hasNext()) { > Map<Vertex, Collection<Vertex>> vertexMap = traversal.next(); > for (Vertex vertex : vertexMap.keySet()) { > Collection<Vertex> coll = vertexMap.get(vertex); > System.out.println("key: " + vertex.value("name") + ", > value: " + coll.size()); > } > } > > TinkerGraph prints > > post-strategy:[TinkerGraphStep(vertex,[])@[a], > RepeatStep([VertexStep(BOTH,vertex), > RepeatEndStep],until(loops(3)),emit(true))@[b], > GroupStep([SelectOneStep(a), NoOpBarrierStep(2500)],[SelectOneStep(b), > DedupGlobalStep, OrderGlobalStep([[id, incr]]), FoldStep])] > > key: marko, value: 6 > key: vadas, value: 6 > key: lop, value: 6 > key: josh, value: 6 > key: ripple, value: 6 > key: peter, value: 6 > > and Sqlg > > post-strategy:[SqlgGraphStepCompiled(vertex,[])@[sqlgPathFakeLabel], > GroupStep([SelectOneStep(a)],[SelectOneStep(b), DedupGlobalStep, > OrderGlobalStep([[id, incr]]), FoldStep])] > > key: marko, value: 0 > key: ripple, value: 0 > key: peter, value: 0 > key: lop, value: 0 > key: josh, value: 0 > key: vadas, value: 0 > > The difference being the NoOpBarrierStep but I am not sure if that is > the culprit or not. > > Thanks > Pieter > > > > > > > On 24/10/2016 21:31, Marko Rodriguez wrote: >> Hi Pieter, >> >> What are the two answers --- TinkerGraph and Sqlg for the respective test >> traversal? >> >> (I suspect the test is bad because group() pushes traversers through with >> bulks and all so the test might just add to a collection without adding >> respecting bulks. Probably should change that test regardless to do like a >> count or something instead). >> >> Marko. >> >> http://markorodriguez.com >> >> >> >>> On Oct 24, 2016, at 12:57 PM, pieter-gmail <pieter.mar...@gmail.com> wrote: >>> >>> Hi, >>> >>> This is on 3.2.3 >>> >>> I have been investigating why >>> `DedupTest.g_V_asXaX_repeatXbothX_timesX3X_emit_asXbX_group_byXselectXaXX_byXselectXbX_dedup_order_byXidX_foldX_selectXvaluesX_unfold_dedup` >>> fails on Sqlg. It is a fairly recently added test. >>> >>> My investigation so far has narrowed the problem to the >>> `PathRetractionStrategy` >>> >>> On the modern graph, >>> >>> GraphTraversal<Vertex, Map<Vertex, Collection<Vertex>>> >>> traversal = g.traversal() >>> .V().as("a") >>> .out().as("b") >>> .<Vertex, Collection<Vertex>>group().by(select("a")) >>> .by(select("b")); >>> printTraversalForm(traversal); >>> >>> Outputs the following on TinkerGraph >>> >>> pre-strategy:[GraphStep(vertex,[])@[a], VertexStep(OUT,vertex)@[b], >>> GroupStep([SelectOneStep(a)],[SelectOneStep(b)])] >>> post-strategy:[TinkerGraphStep(vertex,[])@[a], >>> VertexStep(OUT,vertex)@[b], GroupStep([SelectOneStep(a), >>> NoOpBarrierStep(2500)],[SelectOneStep(b), NoOpBarrierStep(2500)])] >>> >>> And on Sqlg >>> pre-strategy:[GraphStep(vertex,[])@[a], VertexStep(OUT,vertex)@[b], >>> GroupStep([SelectOneStep(a)],[SelectOneStep(b)])] >>> post-strategy:[SqlgGraphStepCompiled(vertex,[])@[b], >>> GroupStep([SelectOneStep(a)],[SelectOneStep(b)])] >>> >>> The difference being that Sqlg does not have the `NoOpBarrierStep` inserted. >>> >>> For TinkerGraph the `NoOpBarrierStep` is being inserted in the >>> `PathRetractionStrategy` on line 113 >>> However this does not happen for Sqlg as Sqlg's GraphStep has >>> `TraverRequirement.PATH` as a requirement which prevents >>> `PathRetractionStrategy` from doing what it does. >>> >>> Is this a bug of sorts? Should Sqlg be adding in the `NoOpBarrierStep`? >>> >>> Thanks >>> Pieter >
