Re: Trend towards artificial keys (GUIDs) sez my textbook...is AI next?
Date: Mon, 17 Dec 2007 12:02:04 -0400
Message-ID: <47669d7d$0$5258$9a566e8b_at_news.aliant.net>
raylopez99 wrote:
> On Dec 16, 3:00 pm, Hugo Kornelis
> <h..._at_perFact.REMOVETHIS.info.INVALID> wrote
>
>
>>>So, from this passage, I think the author does a good job disclaiming >>>the slavish use of GUIDs without understanding their drawbacks, even >>>after the author said he's a "big fan" of such GUIDs. >> >>True. But in the rest of his book, he adds a surrogate key (either GUID >>or IDENTITY) to every entity before and without considering whether one >>is needed. I believe that logical design should be done completely >>without surrogate keys. They MIGHT be introduced during physical design, >>but not before.
Hugo, keys are logical constructs. I fail to see their relevance to physical design.
> OK I'll keep this in mind when trying to architect a database system--
> use natural keys. Which is easier said than done: how unique is
> anybody nowadays ('hair color, height, weight, name, shoe size') with
> 300M Americans and 9B people on the planet? I'm not sure even a GUID
> is 100% safe with those big numbers?! Maybe we need biometrics. But
> I guess most databases are not designed to be so scalable anyway, so
> perhaps natural keys are indeed the best bet.
>
> RL
Sometimes it is possible to invent something that has all of the above properties. For example, when an employer assigns a number to every employee, prints it on a card and tells each employee to include their number on all correspondence, the employer is inventing exactly such a key. Employers were doing that long before computers arrived.
I am not exactly sure what you mean when you say "GUID". If you mean a 128 bit number encoded in hexadecimal and broken into fields, such a thing is neither simple nor familiar to anyone. Received on Mon Dec 17 2007 - 17:02:04 CET