This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 57 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 57 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. In the context of a relational database, what is a key? A) A physical lock securing the database server. B) A unique identifier for a record in a table. C) A type of encryption algorithm. D) A graphical representation of data relationships. Show Answer Correct Answer: B) A unique identifier for a record in a table. 2. The ..... diagram gives a logical structure of the database graphically A) Entity-Relationship. B) Entity. C) Architectural Representation. D) Database. Show Answer Correct Answer: A) Entity-Relationship. 3. Which keyword is used in SQL to remove duplicate rows from a query result? A) UNIQUE. B) DISTINCT. C) DIFFERENT. D) CLEAR. Show Answer Correct Answer: B) DISTINCT. 4. In an Ethiopian airline ticket reservation system, multiple users are trying to book the last available seat at the same time. What database feature helps prevent conflicts? A) Concurrency control. B) Query optimization. C) Data redundancy. D) Data replication. Show Answer Correct Answer: A) Concurrency control. 5. Which field is NOT included in the student database activity table? A) Student ID. B) Grade. C) Age. D) Address. Show Answer Correct Answer: D) Address. 6. What is required for a weak entity set in a relational model? A) One table. B) Two tables. C) No tables. D) A composite table. Show Answer Correct Answer: B) Two tables. 7. Every time attribute A appears, it is matched with the same value of attribute B, but not the same value of attribute C. Therefore, it is true that: A) A $\rightarrow$ B. B) A $\rightarrow$ C. C) A $\rightarrow$ (B, C). D) (B, C) $\rightarrow$ A. Show Answer Correct Answer: A) A $\rightarrow$ B. 8. What is an advantage of using a DBMS? A) Centralized data management B) Increased paper usage C) Manual data entry D) Limited access A) Limited data sharing. B) Decentralized data storage. C) Increased data redundancy. D) A) Centralized data management. Show Answer Correct Answer: D) A) Centralized data management. 9. Which protocol ensures secure communication over the web? A) HTTPS. B) HTTP. C) SMTP. D) FTP. Show Answer Correct Answer: A) HTTPS. 10. Which type of user interacts with the database using SQL queries? A) Database Administrator. B) End User. C) System Analyst. D) All of the above. Show Answer Correct Answer: D) All of the above. 11. What is the main focus of the database approach? A) File-based data handling. B) Manual data handling. C) Centralized data management. D) Decentralized data management. Show Answer Correct Answer: C) Centralized data management. 12. What is needed to answer new questions when using files? A) Manual scanning. B) Automated queries. C) Database transactions. D) Role-based views. Show Answer Correct Answer: A) Manual scanning. 13. Reddit chose which DBMS for handling social media interactions? A) PostgreSQL. B) Microsoft SQL Server. C) Oracle Database. D) Couchbase. Show Answer Correct Answer: A) PostgreSQL. 14. What is the result of a natural join? A) All tuples from the right table. B) All tuples from the left table. C) All tuples from both tables. D) Only matching tuples with redundant columns removed. Show Answer Correct Answer: D) Only matching tuples with redundant columns removed. 15. Which of the following best describes query optimization? A) A process of rewriting queries to improve efficiency. B) A technique to ensure transaction durability. C) A method to normalize database schemas. D) A security mechanism for access control. Show Answer Correct Answer: A) A process of rewriting queries to improve efficiency. 16. Describe the significance of primary keys in a relational database. A) Primary keys are optional and not necessary for database design. B) Primary keys are used to store large amounts of data. C) Primary keys can be duplicated across different tables. D) Primary keys are essential for uniquely identifying records, maintaining data integrity, and establishing relationships between tables in a relational database. Show Answer Correct Answer: D) Primary keys are essential for uniquely identifying records, maintaining data integrity, and establishing relationships between tables in a relational database. 17. What is the result of a left outer join? A) All tuples from the right table. B) All tuples from both tables with duplicates. C) Only matching tuples from both tables. D) All tuples from the left table with NULLs for non-matching right table tuples. Show Answer Correct Answer: D) All tuples from the left table with NULLs for non-matching right table tuples. 18. What SQL command is used to insert new data into a database? A) DELETE. B) UPDATE. C) SELECT. D) INSERT INTO. Show Answer Correct Answer: D) INSERT INTO. 19. What is the main function of a query language in a database system? A) Define the structure of the database. B) Insert new records into the database. C) Retrieve and manipulate data. D) Delete the entire database. Show Answer Correct Answer: C) Retrieve and manipulate data. 20. What is a potential risk of using a database system? A) Simplified management. B) Lower training costs. C) Vendor dependence. D) Increased data sharing. Show Answer Correct Answer: C) Vendor dependence. 21. Which architecture is simplest and cost-effective for personal use? A) 1-Tier. B) 2-Tier. C) 3-Tier. D) Distributed. Show Answer Correct Answer: A) 1-Tier. 22. In agricultural data analysis, statistical functions like AVG, SUM, and COUNT are used to: A) Encrypt data. B) Perform summary calculations. C) Format tables. D) Delete unwanted data. Show Answer Correct Answer: B) Perform summary calculations. 23. In a supertype/subtype hierarchy, subtypes that are lower in the hierarchy inherit attributes from not only their immediate supertype but from all ..... in the hierarchy. A) Subtypes. B) Supertypes. C) Constraints. D) Dimensions. Show Answer Correct Answer: B) Supertypes. 24. What file extension is used for SQL Server database files created in Visual Studio? A) .txt. B) .mdf. C) .sql. D) .db. Show Answer Correct Answer: B) .mdf. 25. Operational databases are primarily used for which of the following? A) Storing data generated by business operations. B) Archiving historical data only. C) Replicating data across multiple sites. D) Supporting only tactical decisions. Show Answer Correct Answer: A) Storing data generated by business operations. ← PreviousNext →Related QuizzesClass 12 Computer Science Chapter 3 Database Management Systems Quiz 1Class 12 Computer Science Chapter 3 Database Management Systems Quiz 2Class 12 Computer Science Chapter 3 Database Management Systems Quiz 3Class 12 Computer Science Chapter 3 Database Management Systems Quiz 4Class 12 Computer Science Chapter 3 Database Management Systems Quiz 5Class 12 Computer Science Chapter 3 Database Management Systems Quiz 6Class 12 Computer Science Chapter 3 Database Management Systems Quiz 7Class 12 Computer Science Chapter 3 Database Management Systems Quiz 8Class 12 Computer Science Chapter 3 Database Management Systems Quiz 9Class 12 Computer Science Chapter 3 Database Management Systems Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books