Re: Database design, Keys and some other things
Date: 26 Sep 2005 09:48:55 -0700
Message-ID: <1127753335.528946.79940_at_f14g2000cwb.googlegroups.com>
Ok, to describe that better with an example:
Consider you have a car and over 20 years you gradually bit by bit change every single part of it. The paint job, the engine, the interior, the chassis... everything, bit by bit. After 20 years it doesn't have a single component that was originally in it. It is still the SAME car?
If yes, then you might agree that the RM model is insufficient and breaks down. If no, then at what point did it become a different car? When the first component changed, when the last component changed, when it was 50% changed? There is absolutely no satisfactory answer.
The implication is that to refer to it, every single tuple should have an artificial key representing our concept of it. Received on Mon Sep 26 2005 - 18:48:55 CEST