Question
Which of the following is the main objective of the 3rd
Normal Form (3NF) in database normalization?Solution
The Third Normal Form (3NF) eliminates transitive dependencies, ensuring that every non-key attribute is directly dependent on the primary key and not on another non-key attribute. This simplifies data integrity and reduces redundancy. For instance, in a table with attributes EmployeeID, DepartmentID, and DepartmentName, dependency between DepartmentID and DepartmentName must be removed into a separate table, leaving only EmployeeID dependent on the DepartmentID. 3NF ensures a structured and efficient database design that minimizes update anomalies. Why Other Options Are Incorrect :
- Remove partial dependencies in a relation : This is the goal of Second Normal Form (2NF) .
- Eliminate duplicate data and achieve minimal redundancy : While normalization reduces redundancy, this is a broader goal and not specific to 3NF.
- Guarantee that every relation contains a candidate key : This is ensured by the very definition of a relation, not by 3NF.
- Ensure that no two rows have identical data across all columns : This is achieved by defining primary keys, unrelated to 3NF.
?3 - 25 Γ 11 = 30 - 15 Γ 12
What will come in place of (?) question mark in the following expression.
Β (β1296 Γ· β36) Γ ? = 120
25% of (?) + (1/4)of 5600 = 2500 β 20% of 1940Β
β? = 80% of 720 - 22% of 2500
What will come in place of (?) question mark in the following expression.
45% of 1600 + ?2 = 1044
32.5% of 40 + (13)2 + 102 = ?
81% of 2300 – 34% of 550 = ?
β? + β1296 + β729 = 464/4Β Β
345 = β2704 Γ· (?% of 104) + 7 3