Why you care about cost when use HepPlanner ? The HepPlanner is aimed for some deterministic planning rules, we usually do not need cost in Hep. Some exceptions like Join reorder may need a cost.
What kind of planning promotion you did ? I'm kind of curious about it. Best, Danny Chan 在 2019年5月1日 +0800 PM9:27，Mark Pasterkamp <[email protected]>，写道： > Dear all, > > While playing around with the HepPlanner I ran into an issue where the > planner wants to rewrite a query with a union rewrite. When the > RelMetaDataQuery computes the cost, the cost instance is a VolcanoCost. > Then when it tries to calculate the cost of one of the union's operands it > is a RelCostImpl which results in the ClassCastException. > > How would I go about solving this issue? As far as my knowledge goes, I am > not able to change the costhandler of the RelMetaDataQuery. Another > approach I could see is removing the cast in the VolcanoCost class, but I > would hope I do not have to do that. > > > With kind regards, > > Mark
