21. The process of converting complex data into a simpler form for storage in a database is called:
A) Data normalization
B) Data validation
C) Data aggregation
D) Data transformation
22. Which SQL command is used to modify the structure of a database table?
A) UPDATE
B) ALTER
C) MODIFY
D) CHANGE
23. The property of a database that ensures all data is consistent and accurate is called:
A) Data Integrity
B) Data Security
C) Data Reliability
D) Data Scalability
24. Which type of join returns only the rows with matching values in both tables?
A) LEFT JOIN
B) RIGHT JOIN
C) INNER JOIN
D) FULL JOIN
25. Which normal form eliminates transitive dependencies in a database table?
A) First Normal Form (1NF)
B) Second Normal Form (2NF)
C) Third Normal Form (3NF)
D) Boyce-Codd Normal Form (BCNF)
