Re: Natural keys vs Aritficial Keys
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Mon, 18 May 2009 13:59:22 -0300
Message-ID: <4a1193e2$0$23766$9a566e8b_at_news.aliant.net>
>
> Really?! I can't possibly say you are wrong about that because I
> wouldn't know, but you do surprise me.
>
>
>
> That seems very implausible in the real world. That is a logical model
> in which if you move one thing, you must--infallibly--move all the
> other things that were there too. That is, it is a world in which it is
> impossible not to also move all the other things. Such situations do
> exist, I grant you, but they are the exception not the rule. But no
> one here (AFAIK) has ever said synthetic/surrogate keys are never
> useful.
Date: Mon, 18 May 2009 13:59:22 -0300
Message-ID: <4a1193e2$0$23766$9a566e8b_at_news.aliant.net>
Roy Hann wrote:
>>To most people, "natural" means "physical"
>
> Really?! I can't possibly say you are wrong about that because I
> wouldn't know, but you do surprise me.
>
>
>>and ends up being quite >>unnatural for some purposes.. When inventory or anything else "moves", >>sometimes "logical" locations are more convenient, allowing the >>replacement of one row to indicate the transfer or re-assignment of many >>"things".
>
> That seems very implausible in the real world. That is a logical model
> in which if you move one thing, you must--infallibly--move all the
> other things that were there too. That is, it is a world in which it is
> impossible not to also move all the other things. Such situations do
> exist, I grant you, but they are the exception not the rule. But no
> one here (AFAIK) has ever said synthetic/surrogate keys are never
> useful.
And no synthetic key will solve the problem that someone was stupid enough to fill a warehouse with no internal subdivision and no way to identify where in the warehouse inventory was put. (In the example cited, the warehouse being a huge gravel field.) Received on Mon May 18 2009 - 18:59:22 CEST