Julian> No, it is not the “unknown collation” subset. It is more like the “don’t care” subset.
Would you please care to explain how the following is possible? (it is from the start of the thread) LogicalProject(subset=[rel#11:Subset#1.NONE.[0]], input=rel#9:Subset#0.NONE.[], Y=[$1]) I read that as follows: "LogicalProject" consumes "don’t care" subset (see "input"), and it claims to produce sorted rows (see "subset" which means the subset LogicalProject belongs to). I'm sure that is impossible. Vladimir
