Database Denormalization MCQ Practice Test

Q1. A database designer is considering denormalizing a table that stores customer information, including their address. The designer wants to improve query performance by reducing the number of joins required to retrieve customer data. Which of the following denormalization techniques would be most suitable for this scenario?

• A. Data Warehousing
• B. Materialized View
• C. Data Duplication ✓
• D. Indexing

Q2. What is the primary reason for denormalizing a database table in a web application that frequently retrieves user information, including their name, email, and phone number, in a single query?

• A. To improve data consistency and integrity
• B. To reduce the number of joins required in a query ✓
• C. To increase the storage space required for the database
• D. To speed up query execution time by reducing the number of rows being processed

Q3. A database designer is considering denormalizing a table to improve query performance. Which of the following is a potential drawback of denormalization?

• A. Increased data consistency due to reduced data redundancy
• B. Reduced data redundancy, but increased data consistency is not guaranteed ✓
• C. Improved data integrity due to additional constraints
• D. Decreased query performance due to increased join operations

Q4. In a denormalized database, what is the primary advantage of using a Materialized View (MV) instead of a trigger-based approach?

• A. It reduces the overhead of query rewriting
• B. It improves query performance by eliminating join operations ✓
• C. It allows for more flexible data aggregation and grouping
• D. It enhances data security by restricting access to sensitive data

Q5. When denormalizing a database, what is the primary goal of storing redundant data in a fact table?

• A. To reduce the number of joins required to retrieve data ✓
• B. To increase the complexity of the database schema
• C. To improve data integrity by reducing the need for data normalization
• D. To enhance query performance by reducing the number of disk I/O operations

Q6. What is a materialized view?

• A. A database object that stores the precomputed result of a query as a physical table ✓
• B. An index built on a view
• C. A temporary result held only in RAM
• D. A stored procedure that runs SELECT statements

Q7. In a denormalized database, which of the following is an example of a materialized view that can improve query performance by reducing the number of joins required?

• A. A calculated column in a table that is not updated by the application.
• B. A table that stores the results of a complex query, updated periodically by a scheduled task. ✓
• C. A relationship between two tables that is stored in a separate table for query optimization.
• D. A column that is used to enforce data integrity by providing a default value.

Q8. You are designing a database for an e-commerce application that stores customer information and order history. The "orders" table has a foreign key "customer_id" that references the "customers" table. However, to improve query performance, you decide to denormalize the database by adding a column "customer_name" to the "orders" table. Which of the following is a benefit of this denormalization?

• A. It reduces the number of joins required to retrieve customer information and order history. ✓
• B. It increases the data redundancy and reduces data consistency.
• C. It improves data security by limiting access to sensitive customer information.
• D. It enhances data scalability by reducing the need for frequent index updates.

Q9. A database is denormalized to improve query performance when dealing with a large number of rows and frequent joins. Which of the following is a common characteristic of a denormalized table?

• A. It has fewer columns than the normalized version.
• B. It has more columns than the normalized version. ✓
• C. It uses a different data type for a frequently queried column.
• D. It has fewer rows than the normalized version.

Q10. When denormalizing a database to improve read performance, which of the following is a correct approach to minimize the impact of data inconsistencies?

• A. Implement optimistic concurrency control with versioning
• B. Use transactions to ensure data consistency across denormalized tables
• C. Employ a data warehousing approach with ETL processes ✓
• D. Utilize materialized views with refresh triggers

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