Understanding Database Normalization

What is the primary purpose of normalization in DBMS?

• The primary purpose of normalization is to reduce data redundancy and improve data integrity.

• To eliminate all data relationships and dependencies.

• To simplify database queries and enhance performance.

• To increase data redundancy and decrease data integrity.

Define First Normal Form (1NF).

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

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

• A table is in First Normal Form (1NF) if it has no restrictions on data types in each column.

• A table is in First Normal Form (1NF) if it contains only atomic values, each column has unique names, and all entries in a column are of the same data type.

What are the requirements for a table to be in 1NF?

• A table is in 1NF if it allows duplicate column names.

• A table is in 1NF if it has atomic values, single type per column, unique column names, and order independence.

• A table is in 1NF if it has multiple data types in a single column.

• A table is in 1NF if it contains non-atomic values.

Explain the concept of Second Normal Form (2NF).

• A table is in Second Normal Form (2NF) if it is in First Normal Form (1NF) and all non-key attributes are fully functionally dependent on the primary key.

• A table is in Second Normal Form (2NF) if it contains duplicate rows.

• A table is in Second Normal Form (2NF) if all attributes are dependent on each other.

• A table is in Third Normal Form (3NF) if it has no transitive dependencies.

What is the significance of removing partial dependencies in 2NF?

• To ensure that all attributes are stored in a single table without normalization.

• To eliminate all functional dependencies in the database.

• The significance of removing partial dependencies in 2NF is to ensure that all non-key attributes depend only on the entire primary key, reducing redundancy and improving data integrity.

• To allow non-key attributes to depend on any part of the primary key.

Describe the conditions for a table to be in Third Normal Form (3NF).

• A table is in 3NF if it has no duplicate rows.

• A table is in 3NF if it has no primary key.

• A table is in 3NF if it is in 2NF and has no transitive dependencies.

• A table is in 3NF if it contains only atomic values.

What is the role of transitive dependencies in 3NF?

• Transitive dependencies are required for achieving 3NF.

• Transitive dependencies can be ignored in 3NF.

• Transitive dependencies only apply to 1NF.

• Transitive dependencies must be eliminated to achieve 3NF, ensuring non-key attributes depend only on the primary key.

Define Boyce-Codd Normal Form (BCNF).

• A relation is in BCNF if it has no transitive dependencies.

• A relation is in BCNF if it contains only atomic values.

• A relation is in BCNF if all attributes are functionally dependent on the primary key.

• A relation is in Boyce-Codd Normal Form (BCNF) if, for every non-trivial functional dependency, the left-hand side is a superkey.

How does BCNF differ from 3NF?

• 3NF requires every determinant to be a candidate key, while BCNF does not.

• BCNF is a stricter form of 2NF, not 3NF.

• BCNF requires every determinant to be a candidate key, while 3NF allows some non-key determinants.

• BCNF allows non-key determinants while 3NF does not.

What are the conditions under which a table is in BCNF?

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

• A table is in BCNF if, for every non-trivial functional dependency, the left side is a superkey.

• A table is in BCNF if it contains no null values.

• A table is in BCNF if all attributes are unique.