That’s a specific physical implantation. If using a key-value storage system then the keys are: Row store: “table id; row id; column id” Column stor

That’s a specific physical implantation. If using a key-value storage system then the keys are: Row store: “table id; row id; column id” Column store: “table id; column id; row id” The difference is the order used to sort the data in storage. In reality, most column store systems use a more complex partitioning scheme with row groups and the like…