morphism">isomorphic</a>, which means that the downstream ExecutionVertices they connect to are exactly the same. The downstream ExecutionVertices belonging to the same JobVertex are also isomorphic, as the upstream IntermediateResultPartitions they connect to are the same too. Since every <a href="//nightlies.apache.org/flink/flink-docs-release-1.14/api/java/org/apache/flink/runtime/jobgraph/JobEdge.html">JobEdge</a> has exactly one distribution type, we can divide vertices and result partitions into group