This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 30 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 30 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. In SQL, which operator is used to test whether a value matches any value in a list? A) BETWEEN. B) LIKE. C) IN. D) EXISTS. Show Answer Correct Answer: C) IN. 2. What type of relationship is represented by a diamond shape in an ER diagram? A) Entity. B) Attribute. C) Relationship. D) Weak entity. Show Answer Correct Answer: C) Relationship. 3. A(n) ..... constraint is a type of constraint that addresses whether an instance of a supertype must also be an instance of at least one subtype. A) Disjoint. B) Overlap. C) Completeness. D) Weak. Show Answer Correct Answer: C) Completeness. 4. What causes most errors in a database? A) SQL. B) Humans. C) Servers. D) Internet access. Show Answer Correct Answer: B) Humans. 5. Hierarchical databases are commonly used in modern applications. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 6. What term is given to a change made in a database? A) A transaction. B) An edit. C) An amend. D) None of the above. Show Answer Correct Answer: A) A transaction. 7. Which one of the following programing states a conceptual framework of object model and is implemented by writing classes and objects. A) Object oriented programming. B) Declarative programming. C) Imperative programing. D) Procedural programing. Show Answer Correct Answer: A) Object oriented programming. 8. Shrinking Phase:Phase where a transaction releases locks but ..... none. A) Acquires. B) Holds. C) Removes. D) Shares. Show Answer Correct Answer: A) Acquires. 9. Which SQL command is used to delete records from a table? A) REMOVE. B) ERASE. C) DROP. D) DELETE. Show Answer Correct Answer: D) DELETE. 10. What is the purpose of a candidate key? A) To store temporary data. B) To uniquely identify records. C) To create a backup. D) To link multiple tables. Show Answer Correct Answer: B) To uniquely identify records. 11. What is the CIA triad in database security? A) Centralization, Integration, Analysis. B) Confidentiality, Integrity, Availability. C) Control, Information, Access. D) Consistency, Isolation, Accessibility. Show Answer Correct Answer: B) Confidentiality, Integrity, Availability. 12. What is the main reason for the 3-level database architecture? A) To increase database speed. B) To provide data independence. C) To reduce storage costs. D) To simplify user interfaces. Show Answer Correct Answer: B) To provide data independence. 13. Explain the concept of indexing in databases. A) Indexing is a technique to enhance data retrieval speed in databases by creating a separate data structure that maps column values to their corresponding rows. B) Indexing refers to the process of backing up database files. C) Indexing is a way to encrypt sensitive data in databases. D) Indexing is a method to delete data from databases efficiently. Show Answer Correct Answer: A) Indexing is a technique to enhance data retrieval speed in databases by creating a separate data structure that maps column values to their corresponding rows. 14. Which modeling technique shows the message flow between objects in an Object Oriented application and also implies the basic associations between classes? A) Sequence Diagram. B) Collaboration Diagram. C) Activity Diagram. D) Class Diagram. Show Answer Correct Answer: B) Collaboration Diagram. 15. The most important challenge of customizing a purchased data model is: A) Getting user buy-in. B) Determining the business rules that will be established through the data model. C) Implementation. D) User training. Show Answer Correct Answer: B) Determining the business rules that will be established through the data model. 16. When the total specialization rule is set for a supertype/subtype relationship, one could roughly compare the supertype to an abstract class in object-oriented programming. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 17. What is the purpose of the INDEX in SQL? A) To create a backup of the database. B) To delete records from a table. C) To improve the speed of data retrieval operations on a table. D) To define relationships between tables. Show Answer Correct Answer: C) To improve the speed of data retrieval operations on a table. 18. Which SDLC phase focuses on identifying data requirements? A) Design. B) Analysis. C) Implementation. D) Maintenance. Show Answer Correct Answer: B) Analysis. 19. The following figure is an example of the overlap rule. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 20. What does DML stand for in SQL and what is its primary function? A) Data Manipulation Language, used to retrieve and manipulate database data. B) Data Modification Language, used to define database structures. C) Data Management Language, used to control access to data. D) Data Mapping Language, used to map data structures. Show Answer Correct Answer: A) Data Manipulation Language, used to retrieve and manipulate database data. 21. The subtype discriminator in the figure below is: A) Part Type. B) Part No. C) Manufactured Part. D) Location. Show Answer Correct Answer: A) Part Type. 22. Which of the following best describes a many-to-many relationship? A) Multiple entities are associated with multiple entities. B) Multiple entities are associated with one entity. C) One entity is associated with multiple entities. D) One entity is associated with one entity. Show Answer Correct Answer: A) Multiple entities are associated with multiple entities. 23. List two types of data integrity constraints. A) Data Redundancy. B) Entity Integrity, Referential Integrity. C) Data Encryption. D) Data Normalization. Show Answer Correct Answer: B) Entity Integrity, Referential Integrity. 24. Which object stores information about related data? A) Document. B) Table. C) Page. D) Screen. Show Answer Correct Answer: B) Table. 25. If transaction Ti gets an explicit lock on the file Fc in exclusive mode, then it has an ..... on all the records belonging to that file. A) Explicit lock in exclusive mode. B) Implicit lock in shared mode. C) Explicit lock in shared mode. D) Implicit lock in exclusive mode. Show Answer Correct Answer: D) Implicit lock in exclusive mode. ← 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