Re: NULL's on the Iseries

["Raul A. Jager W." <raul@xxxxxxxxxx>]

I designed a lot of systems without NULLs, I understand there is no 
hardware support for them, so they need to be implemented as extra bits 
in the file (not prety).
But missing information is a fact of life in DataBase design, and NULLs, 
in the way they are implemented, do the job for me.  The behavior of 
nulls is consistent in all the DataBase engins that adhere to the ISO 
standars, so I find it more convenient to accept the way they work, and 
use them when they make my job easier.
________________________________________________________________________________________________
Joe Pluta wrote:

> The original relational model never included a NULL, and some of the
> great minds of relational database design repudiate the idea.
>
> http://www.dbdebunk.com/page/page/2296478.htm
>
> I highly recommend following the link to "How to Handle Missing
> Information Without Nulls", a pretty self-explanatory title, written by
> Hugh Darwen himself.  When it comes to relational database theory, it
> doesn't get a lot more authoritative than Darwen and Date.
>
> Joe
>
>  
>
> > From: Raul A. Jager W.
> >
> > There is a branch of mathematics that deals with "sets".  Relational
> > databases are based in sets and folow the rules of this branch of
> > mathematics.
> >