Functional Requirements
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[ ] Allow creation of indices on vertices and edges.
[ ] Create ChronoGraphStepStragegy and ChronoGraphStep (see TitanGraphStepStrategy and TitanGraphStep)
[ ] Register ChronoGraphStepStrategy at the global cache (see StandardTitanGraph static initializer)
[ ] Have a look at GraphComputer implementations (Titan, OrientDB, TinkerGraph) and implement one for ChronoGraph (OLAP)


Performance Improvements
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[ ] Have a look at Titan's optimization strategies: AdjacentVertexFilterOptimizerStrategy, TitanLocalQueryOptimizerStrategy
[ ] Have a look at the optimization strategies in OrientDB and TinkerGraph (if any...)
[ ] Think about custom optimization strategies
[ ] Implement a graph element cache based on WeakHashMap<Id, SoftReference<Element>> (or LRU)