explain
Explain the traversal strategies used in a traversal.
Synopsis
explain()
Description
The explain()step is a terminal step that will return a traversal explanation detailing how the traversal is compiled, and the TinkerPop traversal strategies that are used.
Examples
g.V().not(hasLabel('fridgeSensor').or().hasLabel('meal')).
group().by(label).by('name').explain()
The return of explain() for the example:
Traversal Explanation ======================================================================================================================================================================================================================= Original Traversal [GraphStep(vertex,[]), NotStep([HasStep([~label.eq(fridgeSensor)]), OrStep, HasStep([~label.eq(meal)])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] ConnectiveStrategy [D] [GraphStep(vertex,[]), NotStep([OrStep([[HasStep([~label.eq(fridgeSensor)])], [HasStep([~label.eq(meal)])]])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] RepeatUnrollStrategy [O] [GraphStep(vertex,[]), NotStep([OrStep([[HasStep([~label.eq(fridgeSensor)])], [HasStep([~label.eq(meal)])]])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] MatchPredicateStrategy [O] [GraphStep(vertex,[]), NotStep([OrStep([[HasStep([~label.eq(fridgeSensor)])], [HasStep([~label.eq(meal)])]])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] PathRetractionStrategy [O] [GraphStep(vertex,[]), NotStep([OrStep([[HasStep([~label.eq(fridgeSensor)])], [HasStep([~label.eq(meal)])]])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] IncidentToAdjacentStrategy [O] [GraphStep(vertex,[]), NotStep([OrStep([[HasStep([~label.eq(fridgeSensor)])], [HasStep([~label.eq(meal)])]])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] FilterRankingStrategy [O] [GraphStep(vertex,[]), NotStep([OrStep([[HasStep([~label.eq(fridgeSensor)])], [HasStep([~label.eq(meal)])]])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] InlineFilterStrategy [O] [GraphStep(vertex,[]), NotStep([HasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] AdjacentToIncidentStrategy [O] [GraphStep(vertex,[]), NotStep([HasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] CountStrategy [O] [GraphStep(vertex,[]), NotStep([HasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] LazyBarrierStrategy [O] [GraphStep(vertex,[]), NotStep([HasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] DseIncidentToAdjacentStrategy [O] [GraphStep(vertex,[]), NotStep([HasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] HasStepStrategy [P] [GraphStep(vertex,[]), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] QueryStrategy [P] [DsegGraphStep(vertex,[],true,Unordered), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] AdjacentVertexFilterOptimizerStrategy [P] [DsegGraphStep(vertex,[],true,Unordered), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] DsegPropertyLoadStrategy [F] [DsegGraphStep(vertex,[],true,Unordered), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] ProfileStrategy [F] [DsegGraphStep(vertex,[],true,Unordered), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] StandardVerificationStrategy [V] [DsegGraphStep(vertex,[],true,Unordered), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] LambdaRestrictionStrategy [V] [DsegGraphStep(vertex,[],true,Unordered), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])] Final Traversal [DsegGraphStep(vertex,[],true,Unordered), NotStep([DsegHasStep([~label.or(eq(fridgeSensor), eq(meal))])]), GroupStep(label,[TraversalMapStep(value(name)), FoldStep])]
The codes for various steps:
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[D]ecoration
There is an application-level feature that can be embedded into the traversal logic.
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[O]ptimization
There is a more efficient way to express the traversal at the TinkerPop level.
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[P]rovider optimization
There is a more efficient way to express the traversal at the graph system, language, or driver level.
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[F]inalization
There are some final adjustments, cleanups, or analyses required before executing the traversal.
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[V]erification
There are certain traversals that are not legal for the application or traversal engine.
