Chad,

CZH> If I create a constraint, will the index it creates be used for searches and
CZH> sorting?

Yep. It's a full-featured unique index.

CZH> So again.. Now I am REALLY confused.. Whas the difference between a
CZH> unique constraint and a unique index?

The former is logical, the latter physical. The former is implemented
by means of the latter. A FK is logical (a constraint), so it needs to
be linked to something logical (another constraint), not physical.

HTH
--
Nando Dessena
http://www.flamerobin.org