Re: Schema evolution

[dboreham@netscape.com (David Boreham)]

$0.02/wo:

1. Don't. (add new object classes to hold the new attributes instead).
2. If you have to (sometimes the case), think very hard before
doing it. 
3. When you do, never make a change which is not backwards
compatible (e.g. never _remove_ an attribute from a class,
never change an attribute from optional to required).
4. Make sure everyone knows you did it.

A. When you design schema in the first place, beware
of backing yourself into a corner in the future.
Particularly, avoid "required" attributes if you possibly can.