Re: Natural keys vs Aritficial Keys
Date: Thu, 28 May 2009 11:56:46 GMT
Message-ID: <2_uTl.1220$9L2.172_at_nwrddc02.gnilink.net>
> The ORM idea makes the blunder because it assumes incorrectly that the
> values within a set can be identified independently of their value.
> ORM wants to make this assumption so that a variable that records a
> set of values can instead be interpreted as a set of variables.
>
The last several exchanges in this thread have gone over my head. Oddly
enough, this last paragraph brings the discussion full circle, back to where
I started.
Incidentally, I think I understand just a little bit about the difference
between a variable that records a set of values and a set of variables. In
the second case, if I read it right, the cardinality is immutable. In the
first case, the cardinality is variable. If I reread what I just wrote in
the light of this, some of it needs rewording.
Received on Thu May 28 2009 - 13:56:46 CEST