Let’s say we need unique identifiers for map locations. Off hand, you might guess that a normal address makes for a perfect identifier. After all, with geocoding applications, we can easily translate an address to a place on the map. So it would seem like a perfect identifier. However, as I’m sure you have guessed by now, there are lots of use cases for which an address does not make a great identifier of a map location, at least from a database or data mart perspective, or even from an analytical perspective.