Databases: The Quest for Consistency
—SHERLOCK HOLMES IN ARTHUR CONAN DOYLE'S The Adventure of the Copper Beeches
Consider the following arcane ritual. A person takes from a desk a specially printed pad of paper (known as a checkbook), writes some numbers on it, and adds a signature with a flourish. The person then tears the top sheet from the pad, puts it in an envelope, and sticks another piece of paper (known as a stamp) on the front of the envelope. Finally, the person carries the envelope outside and down the street, to a large box where the envelope is deposited.
Until the turn of the 21st century, this was the monthly ritual of anyone paying a bill: phone ...