Re: Two-valued logic
Date: Mon, 29 Dec 2003 00:22:18 GMT
Message-ID: <_sKHb.502995$275.1414945_at_attbi_s53>
"Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in message news:bsnp6q$fdn$1_at_news.netins.net...
> I work with a model that uses a two-valued logic. A NULL value under this
> scenario can be handled logically as a null set value. With this model, a
> NULL then = a NULL because a null set equals a null set..
I'm not sure I understand. Are you saying that your model includes the empty set? That seems sound if unremarkable.
> My impression from reading Date and others is that the three-valued logic of
> SQL that is proliferated in RDBMS's does not have a lot of fans. However, I
> don't know if that is really the case or if I just happen to be reading the
> pro-two-valued logic folks.
Most of the authors I've come across are critical of SQL nulls.
> Who is out there that will still defend three-valued logic within databases
> and suggest that it is a better strategy than using a two-valued approach?
> Would it be accurate to state that most database theorists agree that a
> two-valued logic provides significant benefits?
The one person I respect who defends nulls is Lee Fesperman. He
has a web site for his RDBMS product; there are whitepapers
there that cover his reasoning.
His website:
"In Defense of Nulls"
http://firstsql.com/
http://firstsql.com/idefend.htm
Marshall Received on Mon Dec 29 2003 - 01:22:18 CET