Re: why NOT NULL in PRIMARY key??

[Jigal van Hemert]

From: "Jay Blanchard"

> Since NULL is the absence of a value and PRIMARY keys must have a value
> a NULL column cannot be included as a portion of a PRIMARY key. AFAIK
> this is the case with every RDBMS out there. Asking the development team
> might get you a more informative response.
> 
> There is a vast difference between a zero value, blank value and NULL
> (absence of value).

The situation is pretty challenging:
- because of high concurrency and huge tables I need to use InnoDB
- InnoDB really needs a PRIMARY key for fast results
- a PRIMARY key does not allow NULL values as part of the key

Anyhow, we something to think about...

Regards, Jigal.