CST363 Week 3

 Third Normal Form (3NF)

The Third Normal Form (3NF) is a level of database normalization that helps eliminate data redundancy and maintain data integrity in relational databases. The guidelines for this level of normalization are summed up well by the description, "a non-key column depends on the key, the whole key, and nothing but the key, so help me Codd." This means that in 3NF, all non-key columns must depend on the primary key and only the primary key. Specifically, 3NF eliminates cases where non-key columns can be determined by other non-key columns, ensuring that dependencies are managed solely by the primary key. This form of normalization is essential for reducing redundancy, preventing anomalies, and ensuring the consistency of the data.

SQL view

A view in SQL is a virtual table created by a query that pulls data from one or more tables in a database. Views are often used to simplify complex queries or create an abstraction layer to hide underlying data structures. Additionally, they can be used for security purposes by limiting access to data that needs to be safeguarded. The structure of a view is similar to that of a table, and a view can be queried like a regular database table. However, there can be some constraints on 'INSERT', 'UPDATE', and 'DELETE' operations depending on the implementation.