CODEWITHSUNDEEP
javagremlintinkerpopjanusgraph
Adelino Silva
Adelino Silva

Reputation: 930

Apache TinkerPop allow duplicated Vertex ID

In this test we can see that it does not allow to insert the same vertex ID for the same datatype, but for different datatype it allows it.

gremlin> graph = TinkerGraph.open()
==>tinkergraph[vertices:0 edges:0]
gremlin> g = graph.traversal()
==>graphtraversalsource[tinkergraph[vertices:0 edges:0], standard]
gremlin> g.V()

# generate vertex id automatically by UUID.randomUUID()
gremlin> g.addV().property(id,UUID.randomUUID())
==>v[b47bb233-9a2a-49c8-8ada-0ac0fe9be6f2]
gremlin> g.V()
==>v[b47bb233-9a2a-49c8-8ada-0ac0fe9be6f2]

# generate vertex id manually as UUID datatype.
gremlin> g.addV().property(id,UUID.fromString("c2d673de-2425-4b42-bc1e-68ff20e3b0a8"))
==>v[c2d673de-2425-4b42-bc1e-68ff20e3b0a8]
gremlin> g.V()
==>v[c2d673de-2425-4b42-bc1e-68ff20e3b0a8]
==>v[b47bb233-9a2a-49c8-8ada-0ac0fe9be6f2]

# generate vertex id manually as STRING datatype.
gremlin>  g.addV().property(id,"c2d673de-2425-4b42-bc1e-68ff20e3b0a8")
==>v[c2d673de-2425-4b42-bc1e-68ff20e3b0a8]
gremlin> g.V()
==>v[c2d673de-2425-4b42-bc1e-68ff20e3b0a8]
==>v[b47bb233-9a2a-49c8-8ada-0ac0fe9be6f2]
==>v[c2d673de-2425-4b42-bc1e-68ff20e3b0a8]

# here we can see the vertex with same id duplicated.
gremlin>  g.V().id()
==>c2d673de-2425-4b42-bc1e-68ff20e3b0a8
==>b47bb233-9a2a-49c8-8ada-0ac0fe9be6f2
==>c2d673de-2425-4b42-bc1e-68ff20e3b0a8

# trying to insert it again as UUID datatype.
gremlin> g.addV().property(id,UUID.fromString("c2d673de-2425-4b42-bc1e-68ff20e3b0a8"))
Vertex with id already exists: c2d673de-2425-4b42-bc1e-68ff20e3b0a8

# trying to insert it again as STRING datatype.
gremlin>  g.addV().property(id,"c2d673de-2425-4b42-bc1e-68ff20e3b0a8")
Vertex with id already exists: c2d673de-2425-4b42-bc1e-68ff20e3b0a8

Upvotes: 1

Views: 143

Answers (1)

HadoopMarc
HadoopMarc

Reputation: 1581

It is expected behavior. You can do:

gremlin> g.V().project('id', 'class')
  .by(id())
  .by(map{it->it.get().id().getClass()})
==>[id:b6609a02-4574-4e6f-87ab-6ea3edaa9e55,class:class java.lang.String]
==>[id:b6609a02-4574-4e6f-87ab-6ea3edaa9e55,class:class java.util.UUID]

Apparently, comparing the String object and the UUID object always results in false.

By the way, the graph you opened is a TinkerGraph which is shipped with JanusGraph as part of Apache TinkerPop. JanusGraph itself does not allow vertex id's to be specified, unless explicitly configured that way.

Upvotes: 2

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