Re: O'Reilly interview with Date
- From: "David Cressey" <david.cressey@xxxxxxxxxxxxx>
- Date: Thu, 11 Aug 2005 23:59:31 GMT
"Marshall Spight" <marshall.spight@xxxxxxxxx> wrote in message
news:1123693335.220521.200510@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> I don't think the "overloading" argument is quite right; you
> necessarily have to unify the column namespaces when you join,
> unless you don't want to enforce any column naming discipline
> at all (that is, allow columns with no names, or illegal names,
> or two columns with the same name) which I don't think is tenable.
>
> The namespace unification issue matches quite well with the
> predicate logic model as well; when you do some logical
> operation on two propositions, you necessarily have to unify
> their predicate's namespaces.
Well, I'm not arguing against namespace unification as such. I just think
it shouldn't be done on the column names.
>
> The idea of joining only on FK or some references constraint
> is attractive, but I'm not sure if it's general enough. Sometimes
> you want to join Tables A, B, and C, where B and C both reference
> the primary key of A. What would that do? Or what if a table
> references a primary key twice?
>
If a table contains two references to the same primary key, then a natural
join would join the reference table in twice, wouldn't it?
>
> Marshall
>
.
- References:
- O'Reilly interview with Date
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- Re: O'Reilly interview with Date
- From: erk
- Re: O'Reilly interview with Date
- From: dawn
- Re: O'Reilly interview with Date
- From: erk
- Re: O'Reilly interview with Date
- From: Marshall Spight
- Re: O'Reilly interview with Date
- From: Kenneth Downs
- Re: O'Reilly interview with Date
- From: David Cressey
- Re: O'Reilly interview with Date
- From: Marshall Spight
- O'Reilly interview with Date
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