What Is Normalization  In relational database design, the process of organizing data to minimize redundancy  Usually involves dividing a database into two or more tables and defining relationships between the tables  The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.

Terminologies  Candidate Key  One of several possible attributes or combinations of attributes which can be used to identify each record uniquely in a table  E.g., Employees( empID, SSN, lastName, firstName, address, phone, , hireDate) Cadidate Keys: empID, SSN, lastName-firstName- address, .  The actual candidate key that is chosen for use is the primary key.

Terminologies  Primary Key  A field in a table whose value is unique and insures that each record in the table is unique.  Foreign Key  A field in a table containing values that are also found in some primary key field (in a different table)—is used to link one table with another

Levels of Normalization  First Normal Form (1NF)  eliminates repeating groups by putting each value of a multi-valued attribute into a new row  Second Normal Form (2NF)  eliminates functional dependencies on a partial key by putting the fields in a separate table from those that are dependent on the whole key  Third Normal Form (3NF)  eliminates functional dependencies on non- key fields by putting them in a separate table.  At this stage, all non-key fields are dependent on the key, whole key, and nothing but the key.

Lectures--Normalization  Logic Modeling I (6:05) (Introduction) Logic Modeling I  Logic Modeling II (5:56) (Candidate Key) Logic Modeling II  Logic Modeling III (6:47) (Normalization) Logic Modeling III  Logic Modeling IV (6:20) (Example) Logic Modeling IV  Logic Modeling V (3:54) (First Normal Form) Logic Modeling V  Logic Modeling VI (9:09) (Second Normal Form) Logic Modeling VI  Logic Modeling VII (6:04) (Third Normal Form) Logic Modeling VII  Logic Modeling VIII (9:09) (Entity Relation Diagram) Logic Modeling VIII

Lectures (More informal)  What Is Database Normalization (2:51) What Is Database Normalization  Understanding Normalization: Rule of One (2:53) Understanding Normalization: Rule of One  SQL Normalization (5:08) SQL Normalization  Normalization Demonstration (7:49) Normalization Demonstration  Database Normalization (w/Excel) (22:00) Database Normalization (w/Excel)