Re: Little design mistakes that can be easily avoided (2): Listenning to CELKO (and CELKO alikes)

Cimode <cimode_at_hotmail.com> wrote:

>
>Matthias Klaey a écrit :
>> Cimode <cimode_at_hotmail.com> wrote:
>>
>> >On 26 mai, 18:18, Matthias Klaey <m..._at_hotmail.com> wrote:
>> >> Cimode <cim..._at_hotmail.com> wrote:
>> >> >Hi,

[...]

>> ><<Codd also wrote the following:
>> >There are three difficulties in employing user-controlled keys as
>> >permanent surrogates for entities.>>
>> >Again that Codd ? Who's Codd anyway?
>>
>> Surely you must be joking?
>Never joking. Asking questions and trying t make sense out of CELKO's
>posts.

Then it's time for a short history lesson. Edgar F. Codd was the inventor of the relational model (RM). You might start with

  http://en.wikipedia.org/wiki/Edgar_F._Codd

and take it from there. Most important is

  http://en.wikipedia.org/wiki/Codd%27s_12_rules

(Unfortunately the two Computerworld articles where Codd first described his rules do not seem to be available online).

You can download Codds very first paper on the relational model under

  http://www.klaeycomputing.com/Codd/Codd1.pdf

and the paper cited by Celko under

  http://www.klaeycomputing.com/Codd/Codd2.pdf

Both papers should be read and studied by everyone who is interested in database theory. I will leave this link up for a few days only.

If you google for "history codd relational model" you will get lots of hits.

Greetings
Matthias Kläy

-- 
www.kcc.ch