Re: Define "flatten database" ?
Date: Sat, 25 Feb 2006 10:41:40 GMT
Mark Johnson wrote:
> Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be> wrote:
>>1NF: in some cases they tell you to immedeately split off the nested >>columns into separate relations (thus avoiding redundancy) and in others >>the relation is merely flattened and the splitting off is postponed to >>the later normalization steps. So the question is this. Can we always >>use both approaches and if we can does it matter for the end result >>which one we take?
> Which some, here, find quite objectional is that reference to a
> table/relation as being in any way, 'flat'.
I think that's mainly their problem. :-) Most real experts in database theory are perfectly comfortable with it.
> As for the question, I suspect you had an answer in mind. I don't see
> that it would matter as the 'splitting' is to be done on the same
> columns on the same table, at whatever point one decides to do so.
> Perhaps I might ask a related question. Do you believe that a table
> corresponds, but perhaps only weakly, or even inconsistently, to a
> "relation" as understood in the set theory of the RM, or do you
> believe it is fair to call the database table a "relation", without
> much qualification?
- Jan Hidders