DRILL-6545, LateralPop will have information about list of columns to be excluded from the Lateral output container. Mostly this is used to avoid producing origin repeated column in Lateral output if it's not required from the projection list. This is needed because in absence of it Lateral has to copy the repeated column N number of times where N is the number of rows in right incoming batch for each left incoming batch row. This copy was very costly both from memory and latency perspective. Hence avoiding it is a must for Lateral-Unnest case.