remote exchange (GATHER, SINGLE, [])
    local exchange (GATHER, UNKNOWN, [])
        remote exchange (REPARTITION, ROUND_ROBIN, [])
            final aggregation over (shipmode)
                local exchange (GATHER, SINGLE, [])
                    remote exchange (REPARTITION, HASH, ["shipmode"])
                        partial aggregation over (shipmode)
                            join (INNER, PARTITIONED):
                                remote exchange (REPARTITION, HASH, ["orderkey"])
                                    scan orders
                                local exchange (GATHER, SINGLE, [])
                                    remote exchange (REPARTITION, HASH, ["orderkey_0"])
                                        scan lineitem
