For a research project, I am studying the performance gains in Hive queries achieved through cost based optimization. Rather than just study scenarios where CBO is switched on or off, I would like to study the performance across a “collection" of query plans considered by the CBO (Calcite); for example, the performance of the query plan with the least cost vs the performance of query plan with next higher cost. Performance here is the total completion time.
1. Currently, Hive gets only the least cost plan from Calcite. Is there an interface to get alternate plans ? Say, all plans (read Operator trees) with cost lesser than a threshold. 2. Is there an interface for Hive to get the absolute cost (based on Hive Cost Factory) of a operator tree returned by Calcite ? Thanks, Raajay
