Normalization in DBMS Quiz

Normalization in DBMS

• Normalization is the process of organizing data in a database to eliminate redundancy and dependency, ensuring data integrity and reducing anomalies during data manipulation.
• It is achieved by breaking down large tables into smaller, related tables and defining relationships between them.

Normal Forms

• First Normal Form (1NF)

  • Each table cell should hold a single value.
  • Each column in a table must have a unique name.
  • Entries in a column must be of the same data type.
  • Each column should contain only atomic (indivisible) values.

• Second Normal Form (2NF)

  • Must be in 1NF.
  • All non-key attributes are fully functionally dependent on the primary key.
  • No partial dependencies are allowed.

• Third Normal Form (3NF)

  • Must be in 2NF.
  • There should be no transitive dependencies.
  • A non-key column should not depend on another non-key column.

• Boyce-Codd Normal Form (BCNF)

  • A stricter form of 3NF.
  • Applies when there are multiple candidate keys in a table.
  • Every determinant must be a candidate key.

• Fourth Normal Form (4NF)

  • Deals with multi-valued dependencies.
  • Removes any multi-valued dependencies from a table.

• Fifth Normal Form (5NF)

  • Addresses cases where multiple overlapping candidate keys exist.
  • Ensures that any join or union decomposition is lossless.