Re: Constraints and Functional Dependencies
Date: 24 Feb 2007 21:41:18 -0800
Message-ID: <1172382078.860707.11350_at_q2g2000cwa.googlegroups.com>
On Feb 24, 1:29 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
> UPDATE, INSERT and DELETE are all simply short-hands for popular
> assignment statements with hooks for statement-specific triggered
> procedures. UPDATE is logically equivalent to DELETE/INSERT (generally
> without triggering delete or insert triggered procedures but a different
> triggered procedure instead.)
I've always been uncomfortable with the use of the word "short hand"
in this context. Admittedly I can't point to a formal definition of
the
term, but nonetheless it seems to me to connote that the mutative
operators will have not only the same semantics as the associated
assignment would, but actually expand into exactly that, and thus
have the same operational characteristics. Which I think would suck.
So I think it's important to be clear that we mean that the two
have the same semantics, but not necessarily the same operational
characteristics. Which I think is what *you* have in mind when you
say that; I think "shorthand" is your shorthand for "same semantics
but not necessarily anything else." (Correct me if wrong.) But I'm
not sure everyone will come across with the same idea.
> One wonders what a general assignment statement should
> trigger--especially assignments with logically equivalent results.