>Rich wrote: >"relational theory knowledge is akin to needing to understand the internal combustion engine in order to drive" I disagree. This is like stating that the endusers of database applications need to know relational theory. They do *not*, of course. I see, you correct yourself later on: >"I think I *am* in favor of that requirement if the SQL professional is designing (* database) software" (*) insert by me. If SQL professionals would know about the underlying theories, then a lot (a real huge big lot) of FUD in our profession would disappear. <rant> This FUD gave us Java. And boy, aren't we happy about that? </rant> -- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Toon Koppelaars RuleGen BV +31-615907269 toon_at_rulegen_dot_com www_dot_rulegen_dot_com Author: "Applied Mathematics for Database Professionals"