Re: does a table always need a PK?

Centuries ago, Nostradamus foresaw when tonyisyourpal_at_netscape.net (Tony Douglas) would write:
> "Bob Badour" <bbadour_at_golden.net> wrote in message news:<OYy2b.694$FE.81687684_at_mantis.golden.net>...
>> I have long argued that adequate support for user defined types and for
>> adequate physical independence would give me all the tools I really need to
>> devise my own ad hoc solutions. My own ad hoc solutions would be guaranteed
>> consistent because I would have to construct them on a theory based
>> structural framework consisting of relations and a formal, extensible type
>> system.
>
> I think this is absolutely right. I'm still in a way stunned that
> most current SQL databases are lumbered with what amounts to the
> type system of FORTRAN. Why have nulls if you can have something
> even at the horrid level of the Pascal variant record for dealing
> with "out of band" indicators ? You even get to stick with the
> boolean logic we all know and love !
>
> That said, I'm still not 100% convinced about the type inheritance /
> possreps suggestion of Tutorial D. It's thoroughly defined, and very
> elegant (for what it's trying to achieve); I'm just not sure I'm
> asking the question it's answering. I think achieving a type system
> of at least the level of the Milner type system in Standard ML would
> be a perfectly good start, and a massive advance on where we are
> today.

But that would likely cause anyone trying to use typically-used languages like COBOL, PL/1, BASIC, C, and C++ utter conniptions.

The managers would cry 'But where can we get ML programmers? There's no market for that!'

The programmers would cry 'Who is this Milner guy, and what did he do to my types?'

The ML programmers would look on in horror: "You want us to rewrite the _PAYROLL_ system?!?!"

(And the guys at INRIA would shortly thereafter take over the world...)

I'm still a little suspicious of the way some of the type inheritance in Tutorial D works; some of it looks as though it's actually leading to a hierarchical structure, which would break some of the "relationality." Of course, it could be that I am misreading it; the "Tutorial" is not much of a tutorial...

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