remote exchange (GATHER, SINGLE, [])
    final hashaggregation over (ss_customer_sk, ss_item_sk)
        local exchange (GATHER, SINGLE, [])
            partial hashaggregation over (ss_customer_sk, ss_item_sk)
                join (LEFT, PARTITIONED):
                    scan store_sales_item_customer_solddate
                    local exchange (GATHER, SINGLE, [])
                        remote exchange (REPARTITION, hive:buckets=1, hiveTypes=[bigint], ["sr_item_sk"])
                            scan store_returns
