Recently I work on grouping sets and I find the last param numGroups of create_groupingsets_path is not used.
In create_groupingsets_path we use rollup->numGroups to do cost_agg.
Yes indeed. The param 'numGroups' was used originally when we first introduced in create_groupingsets_path(), and then all its references inside that function were removed and replaced with the numGroups inside RollupData in b5635948.
I generate a diff.patch, which is sent as an attachment.
BTW, the patch looks weird to me that it seems operates in the inverse direction, i.e. it's adding the param 'numGroups', not removing it.
