Amazon Neptune has an alternative query engine known as the DFE that uses DB instance resources such as CPU cores, memory, and I/O more efficiently than the original Neptune engine.
Note
With large data sets, the DFE engine may not run well on t3 instances.
The DFE engine runs SPARQL, Gremlin and openCypher queries, and supports a wide variety of plan types, including left-deep, bushy, and hybrid ones. Plan operators can invoke both compute operations, which run on a reserved set of compute cores, and I/O operations, each of which runs on its own thread in an I/O thread pool.
The DFE uses pre-generated statistics about your Neptune graph data to make informed decisions about how to structure queries. See DFE statistics for information about how these statistics are generated.
The choice of plan type and the number of compute threads used is made automatically based on pre-generated statistics and on the resources that are available in the Neptune head node. The order of results is not predetermined for plans that have internal compute parallelism.
