Re: A Normalization Question
From: Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be>
Date: Fri, 09 Jul 2004 16:59:53 GMT
Message-ID: <daAHc.180641$aX4.8664135_at_phobos.telenet-ops.be>
>
> Because the three strings each represent the same thing, the string
> 'brown', it is redundant.
Date: Fri, 09 Jul 2004 16:59:53 GMT
Message-ID: <daAHc.180641$aX4.8664135_at_phobos.telenet-ops.be>
Neo wrote:
>>>... try again as to why the same thing (string 'brown') >>>[stored] three times in a db is not redundant. >> >>Because there is no update anomaly.
>
> Because the three strings each represent the same thing, the string
> 'brown', it is redundant.
So you keep on claiming, but the standard definition of redundancy in normalization theory says otherwise.
> I realize the following are unusual examples, however a general data
> model can't (application above it can) have prejudices as to what
> updates are unusual. Suppose, the world is taken oven by Islam and
> they desire every string in a computer to be spelled backwards, thus
> 'brown' needs to be updated to 'nworb'.
That means the schema is changing and then all bets are off because the notion of update anomaly is defined only with respect to a fixed schema.
- Jan Hidders