Re: Designing DB in accordance with the relational model

On Nov 12, 12:25 am, Gene Wirchenko <ge..._at_ocis.net> wrote:
>   It sounds as if you are getting into premature optimisation.
Well. I'd rather think of it as a willing to do everything correctly from the very start. Right now, I am thinking about logical level, i.e. the set of relvars an application will see and work with. On a level of SQL planning I will use wide tables with NULLs in them, no doubts.

On Nov 12, 4:33 am, Clifford Heath <n..._at_spam.please.net> wrote:
> Roy Hann wrote:
> > Clifford Heath wrote:
> >> [Nulls] are an
> >> efficiency feature, added to allow a reduction in the number of
> >> physical tables required,
> > *PLONK!*  And on so many levels too.
>
> Twat.
>
> If you want to avoid NULLs, you add tables. Cleaner, but typically slower.
> Perhaps not the way it should be, but the way existing RDBMS' are.
If I want to avoid using NULLs on a logical level (and I do), I'd just add views which are projections of a NULL-containing table and would work with them only, not with the table itself. Well, it would require some self-control to not touch the table but only the views derived from it. Received on Fri Nov 12 2010 - 11:28:54 CET