Re: "Hard" Key Determination Method is Easy. DNF Paper is Done..

Nicola

> On Monday, 9 February 2015 21:18:17 UTC+11, Nicola wrote:
> In article <bef08005-8a74-4b97-8fce-652022af0e0c_at_googlegroups.com>,
> Derek Asirvadem <derek.asirvadem_at_gmail.com> wrote:
>
> > Ok, so it wasn't a contradiction,
> > it was missing requirements. "multiple chapters" implies:
> > - multiple courses
> > - one exam per course
> > - multiple chapters per exam, in one sitting
>
> Yes.

That's not what you when you gave me the incorrect info. Good to know that you agree with the info that I found myself.

> > - No redundancies;
>
> In StudentExamination, the fact that, say, Room 101 will host the
> Networks exam on 3/10, 1pm, is repeated for each student taking that
> exam. This is a form of redundancy.
>
> > no Update Anomalies
>
> Yes, that may well be the case, with the proper inter-relational
> constraints in place. For example, the redundancy mentioned above does
> not cause update anomalies by virtue of a referential integrity
> constraint.
>
> > Back to work.
>
> Definitely.
>

Reminds me of the poor relations when they visit. They look up at the big house, the swimming pool, the horses, and they say, "yes, but they would be having marital problems". Sick, yes.

Either put up, or shut up. Name the missing constraint or tick mark or whatever it is that you see, or say nothing. Because if you do say something, you will be proving something bout yourself. If something is missing, name it, use the table names with some character between them. Keep the pharisee to yourself.

The definition of Redundancy is that it cause an Update Anomaly. One, for each occurrence. Each proves the other. If there are 12 Redundancies, there are 12 Update Anomalies. If there are Update Anomalies, it is caused by a Redundancy.

So when you argue against yourself, as above, you destroy your own point.

> the redundancy mentioned above does
> not cause update anomalies

Then it is not a Redundancy, silly, give it another name.

> by virtue of a referential integrity
> constraint.

Really ? You don't know that there are many types of constraints, you know only one ?

I have six, not counting three that I publish only for customers. Obviously, you won't see the three, they are not documented, just look for the six minus one.

Because, if you don't know the others, the five, you will not recognise them in the model, and I have field you hilarious accusations. So, please, go off and do some reading. Assist me in reducing the typing I have to do for you.

Cheers
Derek Received on Mon Feb 09 2015 - 13:27:02 CET