Are you as old as me then? Or is it still on the radio??!
Regards
HJR
"Paul Brewer" <paul_at_paul.brewers.org.uk> wrote in message
news:3ddea001_2_at_mk-nntp-1.news.uk.worldonline.com...
> "Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message
> news:cAeD9.81459$g9.229455_at_newsfeeds.bigpond.com...
> >
> > "Paul Brewer" <paul_at_paul.brewers.org.uk> wrote in message
> > news:3ddd6f87$2_3_at_mk-nntp-1.news.uk.worldonline.com...
> > > "Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message
> > > news:FYVC9.80802$g9.227327_at_newsfeeds.bigpond.com...
> > > > Whatever happened to Boyce-Codd Normal Form, huh??
> > > >
> > > > Huh?
> > > >
> > > > Come on... TNF is for wimps.
> > > >
> > > > Regards
> > > > HJR
> > > > ;-)
> > > >
> > > Howard,
> > >
> > > Have to (yet again) confess ignorance. I am familiar with Uncle Ted's
> > > principles, but I have never heard of Mr. Boyce.
> > > Is this 4NF and 5NF? (Attribute, Value pairs) and all that stuff? If
so,
> > I'd
> > > theoretically like the idea of designing the entire application in one
> > > table, but I might have a slight concern about how it would eventually
> > > perform in the real world <g>
> > >
> > > Regards,
> > > Paul
> >
> > Are you sitting comfortably? Then I shall begin.
> >
> > A relation is in Boyce-Codd Normal Form (BCNF) if every determinant is a
> > candidate key.
> >
> > Or, as I saw it put more pithily (and accurately, if more inscrutibly):
> >
> > relation R with FDs F is in BCNF if, for all X ? A in F+
> > (where X contains a key for R)
> >
> > Got that? No??
> >
> > In other words (hold on to your hats):
> >
> > R is in BCNF if the only non-trivial FDs over R are key constraints.
> >
> > From this it follows (follows???!) that there is no dependency in R that
> can
> > be predicted using FDs alone, and also that if we are shown two tuples
> that
> > agree upon the X value, we cannot infer the A value in one tuple from
the
> A
> > value in the other.
> >
> > Dontyajustlurve this stuff??!
> >
> > I confess to having lifted this lock, stock and several smoking barrells
> > from a couple of sites trawled after searching on Google.
> >
> > All I really know about BCNF in plain English is that it is more
> normalised
> > than 4NF or 5NF. It is, in fact, the most normalised you can get -it's
> > actually theoretically impossible to normalise further than good old
BCNF.
> > Which is why no-one uses it because attempting to do so would burst
> several
> > blood vessels in the brain and result in absolutely abysmal performance.
> >
> > But I like trotting it out at dinner parties, just to impress.
> >
> > The last dinner party to which I was invited was in 1986. I wonder why?
> >
> > :-)
> >
> > Regards
> > HJR
> >
> >
>
> Howard,
>
> Quite straightforward, then.
> I'm looking forward to explaining this to the business....
>
> By the way, on the 'sitting comfortably' question, I checked:
>
> pb> lsnrctl status
>
> LSNRCTL for 32-bit Windows: Version 9.2.0.1.0 - Production on 22-NOV-1957
> 13:45:00
>
> Copyright (c) 1947, 1956, Oracle Corporation. All rights reserved.
>
> Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC0)))
> STATUS of the LISTENER
> ------------------------
> Alias LISTENER
> Version TNSLSNR for 32-bit Windows: Version 9.2.0.1.0 -
> Service "Mother" has 1 handler(s) for this service....
> The command completed successfully
>
>
> Regards,
> Paul ;-)
>
>
>
Received on Fri Nov 22 2002 - 21:52:51 CST
