Stamatis>a case where digest normalization is not desirable and Stamatis>brings problems to a downstream project.
It looks more like a custom normalizer to me rather than "normalization is not desirable". If I read the problem right, the very same idea was #1 in CALCITE-2450: <<For AND, OR, IN: put "simpler" nodes first>>. The current "per rule" and "per rel" overhead is enormous, and it makes it doubtful to use optimizer rules for shuffling predicate order. It might be more efficient to have a consistent normalizer, so the rels with different expression orders are not generated at all. Vladimir