Achilleus, > In other words, with surrogate keys, you eliminate the chance > that your original design was flawed due to lack of important > initial knowledge.
Well, you don't *eliminate* it, but you do decrease it. I'd say, yes, this is an important 4th reason: 4) Your spec may be incorrect and surrogate keys make it easier to make design changes in production. Once again, though, this is an *implementation* issue and not a *logic* issue, as I asserted ... -- -Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings