Re: boolean datatype ... wtf?

On 1 okt, 02:24, Brian <br..._at_selzer-software.com> wrote:
> On Sep 30, 3:22 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
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> > Paul Mansour wrote:
> > > On Sep 30, 11:17 am, Tegiri Nenashi <tegirinena..._at_gmail.com> wrote:
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> > >>On Sep 30, 3:32 am, Tony Andrews <tony.andrew..._at_gmail.com> wrote:
> [Quoted]
> > >>> create table applications_with_immobolisers (application_id
> > >>>references applications primary key);
> > >>>... etc.
>
> > >>>That may be the right approach in a theoretical true RDBMS, but I'm
> > >>>pretty sure it would get me sacked as a lunatic in any SQL-based DBMS
> > >>>team!
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> > >>Ah, this is why one don't usually find any unary relation in SQL Dbms!
> > >>This is very odd from theoretical perspective as one might expect
> > >>there are many more unary relations than binary ones, many more binary
> > >>than ternary and so on (akin to Zipfian distribution). Well SQL made
> > >>creating a table more expensive than adding an column, that is one of
> > >>its many implementational sins.
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> > > Isn't creating a new table conceptually more expensive than adding a
> > > column, regardless of the implementation? Perhaps this is why Date's
> > > well-known supplier and parts database has a S.STATUS column rather
> > > than a STATUS table, and P.COLOR column column rather than P.COLOR
> > > table, and all the attendent foreign keys.
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> > Concepts are free.
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> > If one uses 6NF for temporal data, little difference exists between
> > creating a new table or adding a column.- Hide quoted text -
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> > - Show quoted text -
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> Ignorance or irresponsibility?
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> Is Badour exhibiting his complete ignorance to the consequences of
> decomposing a 5NF database scheme into one that is in 6NF?  Unless the
> 5NF scheme was already in 6NF, the equivalent 6NF scheme will contain
> numerous additional cyclical referential constraints that were not
> present in the 5NF scheme.  Assuming that the introduction of the
> additional attribute doesn't violate 5NF, no additional constraints
> are required that aren't implied by the candidate key constraint on
> the 5NF relation scheme.  Introducing a 6NF relation scheme to the
> equivalent 6NF database scheme requires explicit declaration of a
> cyclical referential constraint.  If it isn't just plain ignorance,
> then doesn't such careless disregard of those consequences border on
> irresponsibility?  People here have the impression that Badour knows
> what he's talking about.  Deliberately or carelessly misleading those
> who look up to them is behaviour usually attributible to politicians
> and lawyers, con-men and thieves--predatory personalities.- Tekst uit oorspronkelijk bericht niet weergeven -
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> - Tekst uit oorspronkelijk bericht weergeven -

Explain "cyclical referential constraint".

And explain "additional attribute". Received on Fri Oct 01 2010 - 14:18:30 CEST