10.2.2 Normalization

• What is the primary goal of normalization in databases?

  Reduce redundancy and improve data integrity
• Normalization involves dividing tables into smaller, related tables to reduce redundancy
• Every row in a 1NF table must have a primary key.
• Steps to convert a table to 1NF

  1️⃣ Eliminate repeating groups

  2️⃣ Ensure each attribute contains atomic values

  3️⃣ Assign a primary key to each row
• What type of dependencies does 2NF aim to remove?

  Partial dependencies
• In 2NF, each non-key attribute must be fully dependent on the entire primary key
• Transitive dependencies are removed in 3NF.
• What is the condition for a functional dependency $X \rightarrow Y$ in BCNF?


  X must be a superkey
• Normalization reduces storage space by eliminating redundant data
• What is the benefit of improved data consistency in normalized databases?

  Changes only need to be made in one location
• Match the database feature with its characteristic:

  Unnormalized Database ↔️ High redundancy

  Normalized Database ↔️ Low redundancy
• Normalization can be represented as $\text{Data} \rightarrow \text{Tables} +$$\text{Relationships}$.
• What is the primary goal of 1NF in normalization?

  Eliminate repeating groups
• A table with multiple phone numbers per employee is converted to 1NF by creating separate rows
• The first normal form requires that each attribute contains atomic
• A table with multiple phone numbers per employee violates 1NF.
• Arrange the normal forms in ascending order of complexity:

  1️⃣ 1NF

  2️⃣ 2NF

  3️⃣ 3NF

  4️⃣ BCNF
• What is the primary requirement of 1NF?

  Atomic values in attributes
• 2NF requires a table to be in 1NF and have no partial dependencies.
• The second normal form requires the elimination of partial dependencies
• What type of dependency is removed in 2NF?

  Partial
• What is an example of converting a table to 2NF?

  Separating project details
• The third normal form requires the removal of transitive dependencies
• 3NF requires a table to be in 2NF and have no transitive dependencies.
• What is an example of converting a table to 3NF?

  Separating department details
• What type of dependency is removed in 3NF?

  Transitive
• What is the purpose of normalization in database design?

  Reduce redundancy and improve integrity
• Arrange the normal forms in increasing order of dependency reduction.

  1️⃣ 1NF

  2️⃣ 2NF

  3️⃣ 3NF

  4️⃣ BCNF
• In 1NF, each attribute must contain atomic values.
• A table with multiple phone numbers per employee violates 1NF.
• What type of dependency is removed in 2NF?

  Partial dependency
• In 2NF, project details are moved into a separate table.
• 3NF requires a table to be in 2NF.
• What type of dependency is removed in 3NF?

  Transitive dependency
• In 3NF, department details are moved into another table.
• BCNF ensures that every determinant is a superkey.
• What does BCNF require in addition to 3NF?

  Superkey dependency
• What is the primary goal of normalization in databases?

  Reduce redundancy and improve integrity
• There are several normal forms that guide the process of normalization
• The First Normal Form (1NF) requires each attribute to contain atomic values.