after project, some Slot maybe project to another one. So we need to replace ExprId in DistributionSpecHash to the new one. if we do project other than Alias, We need to return DistributionSpecAny other than child's DistributionSpec.
after project, some Slot maybe project to another one. So we need to replace ExprId in DistributionSpecHash to the new one. if we do project other than Alias, We need to return DistributionSpecAny other than child's DistributionSpec.