they're saying they started with the dumb thing, item1_location1 item1_location2 ... item2_location1 item2_location2 every (item, loca

they're saying they started with the dumb thing, item1_location1 item1_location2 ... item2_location1 item2_location2 every (item, location) combo gets its own row, and then they moved to the smarter thing.