cross join:
    final hashaggregation over ()
        local exchange (GATHER, SINGLE, [])
            remote exchange (GATHER, SINGLE, [])
                partial hashaggregation over ()
                    join (INNER, REPLICATED):
                        scan time_dim
                        local exchange (GATHER, SINGLE, [])
                            remote exchange (REPLICATE, BROADCAST, [])
                                join (INNER, REPLICATED):
                                    ReuseTableScan household_demographics (Consumer)
                                    local exchange (GATHER, SINGLE, [])
                                        remote exchange (REPLICATE, BROADCAST, [])
                                            join (INNER, REPLICATED):
                                                scan web_sales
                                                local exchange (GATHER, SINGLE, [])
                                                    remote exchange (REPLICATE, BROADCAST, [])
                                                        scan web_page
    final hashaggregation over ()
        local exchange (GATHER, SINGLE, [])
            remote exchange (GATHER, SINGLE, [])
                partial hashaggregation over ()
                    join (INNER, REPLICATED):
                        scan time_dim
                        local exchange (GATHER, SINGLE, [])
                            remote exchange (REPLICATE, BROADCAST, [])
                                join (INNER, REPLICATED):
                                    ReuseTableScan household_demographics (Producer)
                                    local exchange (GATHER, SINGLE, [])
                                        remote exchange (REPLICATE, BROADCAST, [])
                                            join (INNER, REPLICATED):
                                                scan web_sales
                                                local exchange (GATHER, SINGLE, [])
                                                    remote exchange (REPLICATE, BROADCAST, [])
                                                        scan web_page
