super key, candidate key, determinant

转自：Beginning Database Design Solutions

a superkey is a set of fields that contain unique values. You can use a superkey to uniquely identify the records in a table.

Also recall that a candidate key is a minimal superkey. In other words, if you remove any of the fields from the candidate key, it won’t be a superkey anymore.

A determinant is a field that at least partly determines the value in another field.