The second option is a poor choice because null means specifically "we
don't know" or "we don't have one".

char(1) with a constraint is a better choice from a modeling
perspective. This allows "true", "false", and "i dunno"

On Fri, 2005-09-02 at 11:06 +0200, Bc. Jiri Cincura wrote:
> Hi,
>
> today morning I was thinking about the Boolean simulation in FB 1.5 . I've
> found two solutions.
> 1: char(1) with 'T' and 'F' and some validation (check, trigger)
> 2: char(1) with X (as Yes/True) and NULL (No/False)
>
> What's better (performance, management, ...)?
> How you're working with Boolean?
>