>VolcanoPlanner flattens the composite trait into the default trait value in RelSet.add -> RelTraitSet.simplify
Vladimir, have you tried removing that RelTraitSet.simplify? I remember I have run into that multiple times already, and I suggested removing that "simplify". For example, https://issues.apache.org/jira/browse/CALCITE-2593?focusedCommentId=16750377&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16750377 Vladimir
