remote exchange (GATHER, SINGLE, [])
    local exchange (GATHER, UNKNOWN, [])
        remote exchange (REPARTITION, ROUND_ROBIN, [])
            cross join:
                final aggregation over (partkey)
                    local exchange (GATHER, SINGLE, [])
                        remote exchange (REPARTITION, HASH, ["partkey"])
                            partial aggregation over (partkey)
                                join (INNER, REPLICATED):
                                    scan partsupp
                                    local exchange (GATHER, SINGLE, [])
                                        remote exchange (REPLICATE, BROADCAST, [])
                                            join (INNER, REPLICATED):
                                                scan supplier
                                                local exchange (GATHER, SINGLE, [])
                                                    remote exchange (REPLICATE, BROADCAST, [])
                                                        scan nation
                local exchange (GATHER, SINGLE, [])
                    remote exchange (REPLICATE, BROADCAST, [])
                        final aggregation over ()
                            local exchange (GATHER, SINGLE, [])
                                remote exchange (GATHER, SINGLE, [])
                                    partial aggregation over ()
                                        join (INNER, REPLICATED):
                                            scan partsupp
                                            local exchange (GATHER, SINGLE, [])
                                                remote exchange (REPLICATE, BROADCAST, [])
                                                    join (INNER, REPLICATED):
                                                        scan supplier
                                                        local exchange (GATHER, SINGLE, [])
                                                            remote exchange (REPLICATE, BROADCAST, [])
                                                                scan nation
