Re: PRIMARY KEY on a *group* of columns imply that each column is NOT

On Wed, Apr 27, 2005 at 04:50:23PM +0200,
 Sebastian Böck <sebastianboeck@freenet.de> wrote
 a message of 48 lines which said:

> CREATE UNIQUE INDEX na ON x (name, address) WHERE address IS NULL;

No, because it prevents two tuples with the same value of "name".