256GB is 256 billion bytes. So you can only fit over a hundred billion rows into 256GB if you have zero overhead and every row is smaller than roughly two bytes

256GB is 256 billion bytes. So you can only fit over a hundred billion rows into 256GB if you have zero overhead and every row is smaller than roughly two bytes... ;) [so you couldn't even store a single proper integer in each row in your example] Note I said rack not single server.