Re: Does Codd's view of a relational database differ from that of Date & Darwin? [M.Gittens]

From: mountain man <hobbit_at_southern_seaweed.com.op>
Date: Fri, 10 Jun 2005 01:00:11 GMT
Message-ID: <vC5qe.11726$F7.7218@news-server.bigpond.net.au>

"Ged Byrne" <ged.byrne_at_gmail.com> wrote in message news:1118308482.868028.69490_at_g49g2000cwa.googlegroups.com...
> So in the real world there is missing information, not NULLs.
>
> Are NULLs the only possible solution to the problem of missing
> information?

Well put.

Obviously many solutions may be considered on their respective merits. Codd, Date, SQL-92, and the 2005 "incarnate" versions of SQL-DBMS (ie: the "SQL" of MS, IBM, Oracle for example) represent examples of possible solutions to this problem of missing information.

Some of these use one null, others multiple, and some (Date) try to do without nulls. Which is best in theory? Which is best in practice?

Which of these solutions is to be put forward as the solution preferred by the relational model?

-- 
Pete Brown
IT Managers & Engineers
Falls Creek
Australia
www.mountainman.com.au/software

Received on Thu Jun 09 2005 - 20:00:11 CDT