Database Normalisation Questions Medium
The process of converting an unnormalized table to a normalized table involves several steps.
1. Identify the functional dependencies: Analyze the data in the unnormalized table to determine the functional dependencies between the attributes. This involves identifying the primary key and understanding how the other attributes depend on it.
2. Create separate tables: Based on the identified functional dependencies, create separate tables for each distinct entity or concept represented in the unnormalized table. Each table should have a primary key that uniquely identifies the records.
3. Remove redundant data: Eliminate any redundant data by ensuring that each attribute in a table depends only on the primary key of that table. This helps in reducing data duplication and improves data integrity.
4. Establish relationships: Establish relationships between the tables using foreign keys. Foreign keys are attributes in one table that refer to the primary key of another table, creating a link between the two tables.
5. Normalize further if necessary: If the resulting normalized tables still have dependencies or anomalies, further normalization can be applied by repeating the above steps. This is known as higher normal forms, such as second normal form (2NF), third normal form (3NF), and so on.
6. Test and validate: Finally, test and validate the normalized tables to ensure that they accurately represent the original data and maintain data integrity. This involves checking for any data inconsistencies or anomalies and making necessary adjustments.
Overall, the process of converting an unnormalized table to a normalized table aims to organize the data in a structured and efficient manner, reducing redundancy and improving data integrity.