I don't, I would assume that the HepPlanner.findBestExp() calculates the cost somewhere down the line
On Thu, May 2, 2019, 03:31 Yuzhao Chen <[email protected]> wrote: > 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 >
