Re: more on delete from join
Date: Wed, 02 Sep 2009 22:17:00 GMT
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.
Joe Received on Wed Sep 02 2009 - 17:17:00 CDT