Row and Column Storage

A small travel office can keep its seat bookings on paper in two ways. In the first, every booking gets its own form, and each form lists the flight, the seat, the fare class, the fare, and four other fields. In the second, the office keeps eight long lists, one per field, and line 52 of every list belongs to booking 52.

Now ask the office for the total fare per fare class. With forms, a clerk must pick up every form to read two of its eight lines. With lists, the clerk takes only the fare class list and the fare list