Chapter 14

First Normal Form (1NF)

A relation in which the intersection of each row and column contains one and only one value.

Third Normal Form (3NF)

A relation that is in first and second normal form in which no non-primary-key attributes is transitively dependent on a the primary key.

General Definition for Second Normal Form

A relation that is in first normal form and every non-candidate-key attribute is fully functionally dependent on any candidate key. A candidate-key attribute is part of any candidate key.

Second Normal Form (2NF)

A relation that is in first normal form and every non-primary-key attribute is fully functionally dependent on a primary key.

Genderal Definition for Third Normal Form

A relationship that is in first and second normal form in which no non-candidate-key attribute is transitively dependent on any candidate key. In this definition, a candidate-key attribute is part of any candidate key.

Unnormalized form (UNF)

A table that contains one or more repeating groups.

Normalization

A technique for producing a set of relations with desirable properties, given the data requirements of an enterprise. Is a formal method that can be used to identify relations based on their keys and the functional dependencies among their attributes.

Update Anomalies

Can be classified as insertion, deletion, and modification anomalies.

Functional Dependency

Describes the relationship between attributes in a relation.

Full Functional Dependency

Indicates that if A and B are attributes of a relation, B is fully functionally dependent on A if B is functionally dependent on A but not on any proper subset of A.

Transitive Dependency

Is a condition where A, B, and C are attributes of a relation such that if A->B and B->C, then C is transitively dependent on A via B (provided that A is not functionally dependent on B or C.

Determinant

Is of a functional dependency refers to the attribute, or group of attributes, on the left-hand side of the arrow.