Database Management Systems – Multiple Choice Questions (MCQs)

1. 49. What is an exclusive lock (write lock)?

   • A. Allows multiple transactions to read the same data
   • B. Allows only one transaction to modify the data
   • C. Prevents any access to the data
   • D. Allows concurrent modification

2. 50. What is a deadlock in the context of transactions?

   • A. Two or more transactions are blocked indefinitely
   • B. waiting for each other to release resources
   • C. A transaction fails to commit
   • D. The database becomes inconsistent

3. 51. What is database indexing?

   • A. A data structure that improves the speed of data retrieval operations on a database table
   • B. A way to encrypt the database
   • C. A method for data compression
   • D. A technique for normalization

4. 52. Which of the following is a type of index?

   • A. B-tree index
   • B. Hash index
   • C. Full-text index
   • D. Spatial index

5. 53. What is data warehousing?

   • A. A large collection of data used for business intelligence
   • B. A small database for specific tasks
   • C. A real-time transactional database
   • D. A backup of the operational database

6. 54. What is data mining?

   • A. The process of discovering patterns and insights from large datasets
   • B. The process of creating a database
   • C. The process of querying a database
   • D. The process of securing a database

7. 55. What is NoSQL?

   • A. A category of database management systems that do not adhere to the traditional relational model
   • B. A newer version of SQL
   • C. A type of hardware for databases
   • D. A cloud-based database service

8. 56. Which of the following is a type of NoSQL database?

   • A. Key-value store
   • B. Document database
   • C. Column-family database
   • D. Graph database

9. 57. What is a key-value store?

   • A. A NoSQL database that stores data as a collection of key-value pairs
   • B. A relational database with only two columns
   • C. A database that uses only primary keys
   • D. A type of in-memory cache

10. 58. What is a column-family database?

    • A. A NoSQL database that stores data in columns rather than rows
    • B. A relational database with a large number of columns
    • C. A database optimized for analytical queries
    • D. A type of key-value store

11. 59. Which of the following is a database security measure?

    • A. Authentication
    • B. Authorization
    • C. Encryption
    • D. Auditing

12. 60. What is database backup?

    • A. Creating a copy of the database for recovery purposes
    • B. Optimizing the database
    • C. Securing the database
    • D. Normalizing the database