 Database normalization

Database normalization organizes relational schemas using their dependencies to reduce redundant facts and update anomalies. If a table stores (student,course,instructor,office) and each instructor has one office, repeating the office in every enrolment creates multiple places to update. Splitting instructor-office facts into a separate relation can remove that redundancy. A decomposition must be checked for lossless join and, when needed, dependency preservation; merely creating more tables is not a correctness argument. Different normal forms impose different conditions on functional dependencies and other dependency types.

Database normalization is a systematic approach used in designing relational databases to minimize data redundancy and ensure data integrity. The primary goal is to organize the data within the database efficiently, reducing the chances of anomalies during insertions, updates, and deletions. Normalization typically involves dividing a database into two or more tables and defining relationships between the tables. The process is often conducted in stages, referred to as "normal forms," each with specific rules and criteria that must be met.