Re: Normalisation 4NF

"IANAL_VISTA" <IANAL_Vista_at_hotmail.com> wrote in message news:<Xns9593B74F95E93SunnySD_at_68.6.19.6>...
> "Al" <question2004_at_btinternet.com> wrote in
> news:cm44mu$igd$1_at_sparta.btinternet.com:
>
> > You mean you don't know the answer!! Senior DBA?
> >
> >
> > "Sybrand Bakker" <gooiditweg_at_sybrandb.verwijderdit.demon.nl> wrote in
> > message news:s5qao0t1rvvkrejr2ck5dlti48ho9pp45p_at_4ax.com...
> >> On Sun, 31 Oct 2004 19:10:29 +0000 (UTC), "Al"
> >> <question2004_at_btinternet.com> wrote:
> >>
> >>>Hi
> >>>Can any one help me understand the difference between 4NF and 1NF. These
> >>>both refer to a field that has more than one value - so what is the
> >>>difference?
> >>>
> >>>All books I have looked at only consider the 4NF on its own and
> >>>none of them shows an example starting from 1NF and going through all
> >>>stages
> >>>right to 4NF.
> >>>So it is difficult for me to see why the multi-valued field has not been
> >>>taken out
> >>>when examining the repeating groups at the stage of 1NF.
> >>>
> >>>I appreciate a clear explanation or full example showing 1NF to 4NF..
> >>>
> >>>Al
> >>>
> >>
> >>
> >> How much are you willing to pay? This is really an 'assignment'
> >> (probably also your homework) of several hours, so beyond the scope of
> >> a *volunteer* newsgroup.
> >>
> >>
> >> --
> >> Sybrand Bakker, Senior Oracle DBA
> >
>
> Stop top posting.
>

Why, top posting is just a different style? Top posted replies are easier to find and save having to scrool through useless junk. It is the default on most mailing lists like Oracle-L.

As far as 4nf goes I have never understood how any example I have seen is really in 3nf for the multi-valued dependency to exist to begin with.

IMHO -- Mark D Powell -- Received on Mon Nov 01 2004 - 08:42:01 CST