> In the real world, > data changes, even supposedly unchangeable data.
And that's the crux of it. All of the "that design is wrong" arguments in the world won't stop data that has been constant & unique for decades from changing when some manager, rightly or wrongly, sees a "business need" for it. User-provided data can never, ever be counted on to forever and always have the attributes (uniqueness, stability, whatever) described by the users, no matter how many times you are reassured on the subject. The data will very often behave exactly as described, but to base a database design on that assumption is to create a brittle design--as you described. -- Scott Ribe [EMAIL PROTECTED] http://www.killerbytes.com/ (303) 722-0567 voice ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
