Re: Entity vs. Table
Date: Thu, 17 Jun 2004 15:39:15 GMT
Message-ID: <40d1baa0.14945460_at_news.wanadoo.es>
On Thu, 17 Jun 2004 09:17:50 -0400, "Alan" <alan_at_erols.com> wrote:
>> It is perfectly valid to have redundancy in the physical tables.
No, you don't catch this.
You can have a 5 or 6NF logical design and to have a lot of redundancy
in the physical structures.
On the other hand you can have a 5 or 6NF logical design and to have a
lot of redundancy in the logical tables (aggregated tables for
instance).
It seems you don't understand the difference between the physical and
the logical levels.
> This is done often for performance
Normal forms have nothing to do with redundancy in the physical
structures and they also allow redundancy in the logical level.
With a good DBMS you could introduce redundance for performance
purposes without affecting the 5NF design.
>I guess the often ranked number 1 university in the U.S. (by U.S. News &
>
>Yes, if you denormalize to less than 3NF.
>purposes, or ease of reporting, as well as some other reasons. But the
>argument was about 3NF and redundancy.
>World Report) in I.S. grad programs is wrong and you are right.
I don't know what university is, but it is rather probable that your guess is right.
Regards
Alfredo
Received on Thu Jun 17 2004 - 17:39:15 CEST