Re: more on delete from join

From: Joe Thurbon <usenet_at_thurbon.com>
Date: Wed, 02 Sep 2009 22:17:00 GMT
Message-ID: <op.uznhinkjq7k8pw_at_imac.local>



On Thu, 03 Sep 2009 04:23:48 +1000, paul c <toledobythesea_at_oohay.ac> wrote:

> Joe Thurbon wrote:
> ...
>> So, to update a view, rather than update the conclusion directly, one
>> must update (one of) the base relvars that are used to derive the
>> conclusion/view. That is abductive.
>> ...
>
> Joe, if one does that, one is replacing the value of something other
> than the relations that form the join and it wouldn't actually be
> accurate to call it a "join update". To use the term "update", one is
> updating two relvars that point to subsets of the "base relvars".

I'm afraid I don't understand what you mean.

Cheers,
Joe Received on Wed Sep 02 2009 - 17:17:00 CDT

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