// Remove single tuple input subplans and merge unnest aggregate operators.
// TODO Fix EliminateSubplanForSinglePathsRule to check for variables used after the subplan.
// normalization.add(new EliminateSubplanForSinglePathsRule());
normalization.add(new EliminateUnnestAggregateSequencesRule());
normalization.add(new ConvertAssignToUnnestRule());
// Used to clean up any missing noops after all the subplans have been altered.
normalization.add(new RemoveRedundantVariablesRule());
normalization.add(new RemoveUnusedAssignAndAggregateRule());