FanoutRisk
source: marts: marts.orders.flatten[0].via
relationship 'order_of_customer' is one_to_many: flattening it multiplies the mart's own rows once per 'customer' row (S-0023/grain-the-fan-out-guard). Fix: flatten only many_to_one/one_to_one relationships, or model a mart at the grain of 'customer'
