1. NORMALIZATION Handout - 4 DBMS

2. What is Normalization? The process of grouping data elements into tables in a way that simplifies retrieval, reduces data entry and storage, and minimizes the chances of data redundancies and inconsistencies.

3. Reasons for Normalization or Need for Normalization Insertion anomalies If the user fails to insert information about a new database entry into all the places in the database where information about that new entry needs to be stored. Deletion anomalies If the user fails to remove information about an existing data when it is time to remove that data. Updating anomalies : An update of a database involves modifications of data all the places in the database where information about that new entry needs to be stored..

4. 1st Normal Form (1NF) A table (relation) is in 1NF, if each cell is single-valued (i.e., atomic values ) there are no repeating groups. there are no duplicated rows in the table.

5. 2nd Normal Form (2NF) A table is in 2NF, if it is in 1NF and all non-key attributes are fully functionally dependent on its primary key. A table is in 3NF, if it is in 2NF and all non key attributes are independent of each other. 3rd Normal Form (2NF)