Hi Julian, Xiong, thanks for your fast replies!
So first, the default Rules were registered: planner = new VolcanoPlanner(); RelOptUtil.registerDefaultRules(planner, false, true); And as traits I used: planner.addRelTraitDef(ConventionTraitDef.INSTANCE); planner.addRelTraitDef(RelCollationTraitDef.INSTANCE); I digged a bit deeper and what was triggered was the `SortRemoveRule`. If I disabled the Collation Trait this did no longer happen and all worked. I will later try to get a MWE done to reproduce this, if this is a bug. Because the bug would then either be the Full Join producing a wrong Collation or the SortRemoveRule investigating the input Collation wrong, or? But nonetheless, thank you very much! Julian From: Julian Hyde <jhyde.apa...@gmail.com> Date: Tuesday, 11. January 2022 at 00:38 To: dev@calcite.apache.org <dev@calcite.apache.org> Subject: Re: Sort getting removed during optimization Is it possible that the Sort is being removed because some component knows that the input is already sorted? In particular, if a relation has at most one row, it is always sorted. Maybe the planner is deducing this via a some row-count metadata or uniqueness constraint. > On Jan 10, 2022, at 3:35 PM, xiong duan <nobigo...@gmail.com> wrote: > > If I understand correctly, If we remove the BINDABLE_SORT_RULE, the > result will throw an exception about the Plan transformation. So it looks > like a wrong rule's result. If you don't customize the rule, It is a bug, > and please test this using Calcite's new version.
