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Home -> Community -> Usenet -> comp.databases.theory -> Re: Fraud Number 3: U-Gene

Re: Fraud Number 3: U-Gene

From: Erwin <e.smout_at_myonline.be>
Date: 19 Jun 2006 02:14:15 -0700
Message-ID: <1150708455.833329.324080@i40g2000cwc.googlegroups.com>


>
> The consequence of admitting the premice that a relation is a specific
> subset of functions is that you apply all characteritics of a function:

Funny. For some reason I thought that in math, the functions were a subset of the relations. And therefore, the relations are a superset of the functions. It hurts to discover one's own ignorance.

> --> relations, relvars, relvalues are on different level of definition.

Do I understand you correctly that by "relvalue" you mean "any possible value from any possible domain that can occur within a relation" ? You have already pointed out that, acoording to Codd, each defined relation establishes a new domain of its own. I take it that the values of such a domain are indeed "relation values". It would then follow, if I understand you correctly, that all relation values are "relvalues" but not all "relvalues" are relation values.

Then I think that what you mean by "relvalue" is just "value".

> --> R-tables are ONE possible representation of relvars.

Sorry. R-tables are one possible representation of RELATION VALUES. Variables simply do not *need* "being represented". They have a name, a declared type, and they contain a value. Date models variables as a triple of exactly these three components.

> Hope this clarified.

I wouldn't bet on it. Received on Mon Jun 19 2006 - 04:14:15 CDT

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