Understanding Database Normalization

What is the primary goal of database normalization?

• To increase data duplication and decrease data integrity.

• To simplify database queries and enhance performance.

• To eliminate all data from the database entirely.

• To reduce data redundancy and improve data integrity.

Define First Normal Form (1NF).

• A table is in First Normal Form (1NF) if it has a primary key defined.

• A table is in First Normal Form (1NF) if it allows duplicate rows.

• A table is in First Normal Form (1NF) if it contains only atomic values and each entry in a column is of the same type.

• A table is in First Normal Form (1NF) if it contains nested tables.

What are the requirements for a table to be in Second Normal Form (2NF)?

• A table is in 2NF if it contains only numeric data types.

• A table is in 2NF if it is in 1NF and all non-key attributes are fully functionally dependent on the entire primary key.

• A table is in 2NF if all attributes are dependent on at least one non-key attribute.

• A table is in 2NF if it has no primary key.

Explain the concept of functional dependency in the context of normalization.

• Functional dependency is irrelevant to normalization.

• Functional dependency only applies to primary keys.

• Functional dependency is a method for data encryption.

• Functional dependency is a key concept in normalization that defines the relationship between attributes, guiding the organization of data to reduce redundancy and improve integrity.

What is the main difference between Second Normal Form (2NF) and Third Normal Form (3NF)?

• The main difference is that 2NF eliminates partial dependencies, while 3NF eliminates transitive dependencies.

• 2NF and 3NF are the same in terms of database normalization.

• 3NF requires all attributes to be dependent on the primary key, while 2NF does not.

• 2NF focuses on eliminating duplicate data, while 3NF does not.

Describe Boyce-Codd Normal Form (BCNF) and its significance.

• BCNF allows partial dependencies on non-key attributes.

• BCNF is the same as 1NF but with fewer attributes.

• Boyce-Codd Normal Form (BCNF) is a stricter version of 3NF where every determinant is a candidate key, ensuring minimal redundancy and preventing update anomalies.

• BCNF requires all attributes to be unique regardless of keys.

How does normalization improve database design?

• Normalization complicates database queries and slows performance.

• Normalization eliminates the need for indexing in databases.

• Normalization increases data duplication and decreases integrity.

• Normalization reduces redundancy and improves data integrity in database design.

What are the potential drawbacks of normalization?

• Normalization enhances data security

• Potential drawbacks of normalization include increased complexity, performance issues due to multiple joins, and excessive data fragmentation.

• Normalization simplifies data retrieval

• Normalization reduces data redundancy

In which scenarios might denormalization be beneficial?

• Denormalization is primarily for reducing storage space.

• Denormalization is beneficial for improving read performance, simplifying complex queries, and reducing database calls.

• Denormalization is beneficial for increasing write performance.

• Denormalization is used to enhance data integrity.

What is a composite key and how does it relate to normalization?

• A composite key is only used in primary key constraints.

• Normalization eliminates the need for any keys in a database.

• A composite key is a unique identifier made up of two or more columns, used in normalization to ensure data integrity and reduce redundancy.

• A composite key is a single column used for indexing.