local exchange (GATHER, SINGLE, [])
    remote exchange (GATHER, SINGLE, [])
        final aggregation over (ss_customer_sk)
            local exchange (GATHER, SINGLE, [])
                remote exchange (REPARTITION, HASH, ["ss_customer_sk"])
                    partial aggregation over (ss_customer_sk)
                        join (INNER, REPLICATED):
                            join (INNER, PARTITIONED):
                                remote exchange (REPARTITION, HASH, ["ss_item_sk", "ss_ticket_number"])
                                    scan store_sales
                                local exchange (GATHER, SINGLE, [])
                                    remote exchange (REPARTITION, HASH, ["sr_item_sk", "sr_ticket_number"])
                                        scan store_returns
                            local exchange (GATHER, SINGLE, [])
                                remote exchange (REPLICATE, BROADCAST, [])
                                    scan reason
