Re: Natural keys vs Aritficial Keys

lawpoop wrote:

> On May 16, 2:45 pm, Roy Hann <specia..._at_processed.almost.meat> wrote:
>
>> There's no two ways about it.  If the row would be duplicated if not for
>> the spurious distinction of a value that was generated only to ensure
>> distinction and *for no other reason*, it's logically still a duplicate
>> row.
>>
>> By itself a duplicate is absurd but pretty harmless. The problem is
>> when one copy gets updated.
>
> Forgive my naivete, but how does one copy of a duplicate row get
> updated? How does one express that update in SQL, referring to one row
> but not both?
>
> Thank you for disabusing me of my ignorance :)

My point is that the rows are logically duplicate but they have been rendered spuriously distinct by tacking on a meaningless but unique attribute. So such an update is easy (perhaps inevitable).

-- 
Roy