Design Guidelines
1. Design a relation schema so that it is easy to explain its meaning
2. Design the base relation schemas so that no insertion, deletion, or modification anomalies are present in the relations
3. Avoid placing attributes in a base relation whose values may frequently be NULL
4. Guarantees that no spurious tuples are generated

Functional Dependency
X->Y, two sets of attributes X and Y that are subsets of R, for any tuples t₁ and t₂, have t₁[X] = t₂[X], they must also have t₁[Y] = t₂[Y]

Normal Form
1NF, disallow multivalued attributes, composite attributes, and their combinations
2NF, a relation schema R is in 2NF if every nonprime attribute A in R is fully functionally dependent on the primary key of R
    a. for X->Y, if removal of any attribute A from X means that the dependency does not hold, called full functional dependency
    b. if some attributes are removed and the dependency still holds, it is called partial dependency
    c. An attributes is called a prime attributes if it is a member of some candidate key of R, an attribtute is called nonprime if it is not a prime attribute
3NF, a relation schema R is in 3NF if it satisfies 2NF and no nonprimie attribute of R is transitively dependent on the primary key