Re: object algebra
Date: 28 Feb 2004 08:59:42 -0800
Message-ID: <4b45d3ad.0402280859.1add2573_at_posting.google.com>
> > So are you in favor of NULLs (or its patches) and the resulting weaker
> > realtionships?
>
> The above isn't a "patch for" nulls. What does "weaker relationship" mean,
> though? I have no idea how to address that one.
Given EyeColor = {red, brown, Gaping_Unblinking_Sockets},
Given the table:
Person EyeColor
------ --------------
John Gaping_Unblinking_Sockets
Mary Gaping_Unblinking_Sockets
Then, John.EyeColor equals Mary.EyeColor leading an AI program to incorrectly conclude that Mary and Bob have the same EyeColor. This examplifies Date's conclusion: "3VL suffers from the very serious ("showstopper") problem that it does not match reality, that is results that are correct according to 3VL are sometimes incorrect in the real world". Received on Sat Feb 28 2004 - 17:59:42 CET