This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 54 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 54 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which SQL keyword is used to ensure no duplicate rows are returned? A) DISTINCT. B) UNIQUE. C) DIFFERENT. D) SPECIFIC. Show Answer Correct Answer: A) DISTINCT. 2. Which keyword is used to declare a static member in Java? A) Constant. B) Global. C) Static. D) Final. Show Answer Correct Answer: C) Static. 3. In a relational data model, what do rows represent? A) Attributes. B) Records. C) Tables. D) Schemas. Show Answer Correct Answer: B) Records. 4. Which of the following best describes a primary key in a database table? A) A field that can contain duplicate values. B) A unique identifier for each record in a table. C) A field used for sorting data only. D) A field that stores images. Show Answer Correct Answer: B) A unique identifier for each record in a table. 5. Which of the following is an example of a query used in agricultural research? A) List all farms with rainfall less than 600 mm. B) Design a farm logo. C) Print a farmer's photo. D) Play crop growth video. Show Answer Correct Answer: A) List all farms with rainfall less than 600 mm. 6. What is the true definition of big data A) Huge amount of space. B) Large, diverse sets of information. C) Unlimited speed data internet connection. D) Small, undiverse sets of information. Show Answer Correct Answer: B) Large, diverse sets of information. 7. Database administrators want to improve the performance of a complex SQL query. Which technique should they consider first? A) Using query optimization techniques. B) Adding more tables to the database. C) Increasing the number of indexes. D) Reducing data redundancy. Show Answer Correct Answer: A) Using query optimization techniques. 8. Which operation is NOT part of CRUD? A) Create. B) Read. C) Update. D) Sort. Show Answer Correct Answer: D) Sort. 9. An entity set is: A) A collection of similar entities. B) A set of attributes. C) A relationship between entities. D) A table with no primary key. Show Answer Correct Answer: A) A collection of similar entities. 10. What is one of the advantages of using a database management system (DBMS)? A) Isolation of data for each user. B) Limited data consistency. C) Increased complexity of data storage. D) Control of data redundancy. Show Answer Correct Answer: D) Control of data redundancy. 11. What does data dictionary management in a DBMS do? A) Defines data elements and their relationships. B) Encrypts all data transmissions. C) Manages user passwords. D) Schedules system backups. Show Answer Correct Answer: A) Defines data elements and their relationships. 12. If you were collecting and storing information about your music collection, an album would be considered a/an ..... A) Relation. B) Instance. C) Entity. D) Attribute. Show Answer Correct Answer: C) Entity. 13. Which of the following is NOT a component of a DBMS? A) Database engine. B) Query processor. C) Spreadsheet module. D) Data dictionary. Show Answer Correct Answer: C) Spreadsheet module. 14. Which feature of a DBMS helps maintain data consistency and prevents errors? A) Data integrity controls. B) Data redundancy. C) Logical schema. D) File storage system. Show Answer Correct Answer: A) Data integrity controls. 15. A composite key is: A) A key made up of multiple columns. B) A key from another table. C) The largest key in the database. D) A backup of the primary key. Show Answer Correct Answer: A) A key made up of multiple columns. 16. What is a key feature of NoSQL databases? A) Use of SQL for querying. B) ACID compliance. C) Scalability and flexibility. D) Structured data storage. Show Answer Correct Answer: C) Scalability and flexibility. 17. Subtypes should be used when: A) There are attributes that apply to some but not all instances of an entity type. B) Supertypes relate to objects outside the business. C) The instances of a subtype do not participate in a relationship that is unique to that subtype. D) A recursive relationship is needed. Show Answer Correct Answer: A) There are attributes that apply to some but not all instances of an entity type. 18. Which DBMS does DoorDash use for low-latency data processing? A) Couchbase. B) CockroachDB. C) HBase. D) MySQL. Show Answer Correct Answer: B) CockroachDB. 19. What is the purpose of the INTERSECT operation in relational algebra? A) Combine rows from different tables. B) Retrieve common rows from two tables. C) Remove unwanted columns from a table. D) Sort the table in descending order. Show Answer Correct Answer: B) Retrieve common rows from two tables. 20. What is a major consequence of data redundancy in file systems? A) Increased security. B) Data inconsistency and anomalies. C) Easier program maintenance. D) Simplified system administration. Show Answer Correct Answer: B) Data inconsistency and anomalies. 21. A database management system automatically prints all reports once you log in. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 22. Drop table statement A) Deletes the table structure only. B) Deletes the table structure along with the table data. C) Works whether or not referential integrity constraints would be violated. D) Is not an SQL statement. Show Answer Correct Answer: B) Deletes the table structure along with the table data. 23. What is a common issue with files? A) Fast lookups. B) Role-based access. C) Automatic backups. D) Redundancy and inconsistency. Show Answer Correct Answer: D) Redundancy and inconsistency. 24. ..... :User interface layer. A) Presentation Tier. B) Data Tier. C) Business Logic Tier. D) Integration Tier. Show Answer Correct Answer: A) Presentation Tier. 25. Which ERD is best for a university database with Students, Professors, Courses, and Enrollments? A) One table storing everything. B) Separate entities linked with keys and relationships. C) Students and Courses combined in one table. D) Professors stored only as attributes of Courses. Show Answer Correct Answer: B) Separate entities linked with keys and relationships. ← 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