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Re: Perhaps an idiotic question

From: Gene Wirchenko <genew_at_ocis.net>
Date: Thu, 30 Nov 2006 14:41:31 -0800
Message-ID: <lbnum2tp23gr3vk55co7hughh9svhibkek@4ax.com>


Bob Badour <bbadour_at_pei.sympatico.ca> wrote:

>Gene Wirchenko wrote:
>
>> paul c <toledobythesea_at_oohay.ac> wrote:
>>
>>
>>>But it perplexes me even though I admit I have no good reason for asking:
>>>
>>>If I declare a relation (or more properly a relvar) R to have an
>>>attribute A where A's type is the type of R am I declaring a fallacy or
>>>something that is logically possible (ignoring whether it has any use)?
>>
>> I see recursion but no termination.
>>
>> What *is* the use of such a declaration?
>
>What would be the type of a view that combines a recursion or closure
>with the GROUP operation?

     I do not know since I see recursion but no termination. If that is the case, the type can not declared in the first place.

     I can see the attribute being an FK into its own relation. The type then is more pointer to R than R. (That wording is not quite right, but I hope the concept comes through.)

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:

     I have preferences.
     You have biases.
     He/She has prejudices.
Received on Thu Nov 30 2006 - 16:41:31 CST

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