Re: Newbie question

From: Alfredo Novoa <alfredo_novoa_at_hotmail.com>
Date: Tue, 21 Jun 2005 13:06:16 +0200
Message-ID: <k3tfb19funo1l4rfhbtpf8g59s6qn9hgo7@4ax.com>

On Tue, 21 Jun 2005 10:39:12 +0200, Jon Heggland <heggland_at_idi.ntnu.no> wrote:

>> Why is this an advantage?
>
>Cheap answer: Because Oracle doesn't support ON UPDATE CASCADE. :)

It is cheap, indeed :)

>> Most natural keys are never unknown.
>
>It's hard to disagree with qualified statements like that, but as long
>as some natural keys may be unknown or inapplicable or whatever,
>surrogate keys have a use.

Agreed.

>> >Anyway, many "real-world" keys are really surrogates---SSNs, account
>> >numbers, registration numbers, student numbers and so on.
>>
>> And that is a reason for not creating new surrogates.
>
>I'm not saying you should exclusively use surrogates and never natural
>keys.

I am not saying the contrary. I think that we should not create surrogate keys whether we have good natural keys.

> My point was simply "primary key != natural key"---

Trivially true :)

Regards Received on Tue Jun 21 2005 - 06:06:16 CDT