On Sat, May 28, 2005 at 14:27:17 -0300,
David Pratt <fairwinds(at)eastlink(dot)ca> wrote:
> Pretty basic question. Is it necessary to add NOT NULL or UNIQUE NOT
> NULL to SERIAL or is this implicit and unnecessary?
Serials no longer generate a uniqie index by default. So in practice
you will normally want to declare them as PRIMARY KEYs. However there
are cases where you don't need this and the index is extra overhead.