>Question: In your example, does having the title/revision combination violate the 4th normal form, since the primary key consists of a combination of fields? Based on my simple set of rules, it would be kosher, since it's a quanta of data. I guess I don't really follow all the terminology of the definition.

David,

No it does not because 4th NF says that there will not be independantly multivalued components of the primary key. The revision number is dependant on the book title, that is revisons for a given title are sequential. An example of a violation of 4th normal form is below;

Employee Skills Objectives;

Fields
EmployeeID (PK part1)
Skill      (PK Part2)
Objective  (PK Part3)
Skillachieveddate
Objectiveachieveddate

This violates the 4th normal form because skill and objective are both multivalued (that is any employee may have mroe than one skill and more than one objective) and these two fields are not dependant on each other (The skills and objective vary independantly from each other). Some sample data cna show you the problems associated with this NF.

Employee           Skill                 Objective
Smith              Public Speaking       Masters Degree
Smith              Accounting            Masters Degree
Smith              Public Speaking       More Money
Smith              Accounting            More Money

Now if smith decides he wants prestige, how many records do you need to add to this table?

Below is the 4th NF compliant design;

Employee Skill

Fields
EmployeeID
Skill
DateAchieved

Employee Objectives

Fields
EmployeeID
Objective
DateAchieved

In our above question there would only be one record added here to the Employee-Objective table.