SQL Server® 2008 Administration: Real World Skills for MCITP Certification and Beyond

Normal Forms

As just discussed, several normal forms exist. Most databases will perform well if the designer ensures that they meet the third normal form. For this reason, the first, second, and third normal forms will be discussed in detail. Other normal forms, including Boyce-Codd, fifth, and domain-key, will also be briefly defined.

First Normal Form

The entry level of normalization is called first normal form (1NF). A database that does not meet 1NF cannot be called normalized. A database that does meet the requirements of 1NF is normalized, but it is said to be in the first normal form or state. The primary requirement of 1NF is that all tables contain unique records. Stated differently, no table can contain duplicate records.

While different ...