This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Computer Science > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 23 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 23 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. In relational databases, what is the purpose of the UPDATE operation? A) Modify existing records in a table. B) Add new records to a table. C) Combine rows from different tables. D) Remove records from a table. Show Answer Correct Answer: A) Modify existing records in a table. 2. Name three types of database models. A) Relational model, Document model, Key-value model. B) Graph model. C) Object-oriented model. D) Hierarchical model. Show Answer Correct Answer: A) Relational model, Document model, Key-value model. 3. What is a view in SQL? A) A view is a virtual table based on the result set of a SQL query. B) A view is a type of index that speeds up data retrieval. C) A view is a physical table that stores data. D) A view is a command used to delete records. Show Answer Correct Answer: A) A view is a virtual table based on the result set of a SQL query. 4. In the context of a relational database, what is a key? A) A physical lock securing the database server. B) A type of encryption algorithm. C) A graphical representation of data relationships. D) A unique identifier for a record in a table. Show Answer Correct Answer: D) A unique identifier for a record in a table. 5. The ..... diagram gives a logical structure of the database graphically A) Database. B) Entity. C) Entity-Relationship. D) Architectural Representation. Show Answer Correct Answer: C) Entity-Relationship. 6. Which keyword is used in SQL to remove duplicate rows from a query result? A) UNIQUE. B) DISTINCT. C) CLEAR. D) DIFFERENT. Show Answer Correct Answer: B) DISTINCT. 7. 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) Query optimization. B) Data redundancy. C) Data replication. D) Concurrency control. Show Answer Correct Answer: D) Concurrency control. 8. Which field is NOT included in the student database activity table? A) Age. B) Address. C) Student ID. D) Grade. Show Answer Correct Answer: B) Address. 9. What is required for a weak entity set in a relational model? A) One table. B) No tables. C) Two tables. D) A composite table. Show Answer Correct Answer: C) Two tables. 10. 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 $\rightarrow$ (B, C). C) A $\rightarrow$ C. D) (B, C) $\rightarrow$ A. Show Answer Correct Answer: A) A $\rightarrow$ B. 11. What is an advantage of using a DBMS? A) Centralized data management B) Increased paper usage C) Manual data entry D) Limited access A) A) Centralized data management. B) Decentralized data storage. C) Increased data redundancy. D) Limited data sharing. Show Answer Correct Answer: A) A) Centralized data management. 12. Which protocol ensures secure communication over the web? A) HTTP. B) HTTPS. C) SMTP. D) FTP. Show Answer Correct Answer: B) HTTPS. 13. 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. 14. 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. 15. What is needed to answer new questions when using files? A) Role-based views. B) Manual scanning. C) Automated queries. D) Database transactions. Show Answer Correct Answer: B) Manual scanning. 16. Reddit chose which DBMS for handling social media interactions? A) PostgreSQL. B) Oracle Database. C) Microsoft SQL Server. D) Couchbase. Show Answer Correct Answer: A) PostgreSQL. 17. 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. 18. Which of the following best describes query optimization? A) A process of rewriting queries to improve efficiency. B) A security mechanism for access control. C) A method to normalize database schemas. D) A technique to ensure transaction durability. Show Answer Correct Answer: A) A process of rewriting queries to improve efficiency. 19. 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. 20. 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. 21. What SQL command is used to insert new data into a database? A) SELECT. B) DELETE. C) UPDATE. D) INSERT INTO. Show Answer Correct Answer: D) INSERT INTO. 22. 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. 23. What is a potential risk of using a database system? A) Simplified management. B) Lower training costs. C) Increased data sharing. D) Vendor dependence. Show Answer Correct Answer: D) Vendor dependence. 24. Which architecture is simplest and cost-effective for personal use? A) 3-Tier. B) Distributed. C) 1-Tier. D) 2-Tier. Show Answer Correct Answer: C) 1-Tier. 25. In agricultural data analysis, statistical functions like AVG, SUM, and COUNT are used to: A) Delete unwanted data. B) Format tables. C) Perform summary calculations. D) Encrypt data. Show Answer Correct Answer: C) Perform summary calculations. 26. 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) Dimensions. D) Constraints. Show Answer Correct Answer: B) Supertypes. 27. What file extension is used for SQL Server database files created in Visual Studio? A) .mdf. B) .txt. C) .db. D) .sql. Show Answer Correct Answer: A) .mdf. 28. Operational databases are primarily used for which of the following? A) Archiving historical data only. B) Replicating data across multiple sites. C) Storing data generated by business operations. D) Supporting only tactical decisions. Show Answer Correct Answer: C) Storing data generated by business operations. 29. ..... are considered database architects. A) Database administrators. B) Systems administrators. C) Database designers. D) Systems analysts and programmers. Show Answer Correct Answer: A) Database administrators. 30. What is the primary purpose of locking mechanisms in database systems? A) Locking mechanisms are used to speed up data retrieval. B) Locking mechanisms prevent unauthorized access to the database. C) Locking mechanisms ensure that only one transaction can modify data at a time to prevent conflicts. D) Locking mechanisms are only relevant for large databases. Show Answer Correct Answer: C) Locking mechanisms ensure that only one transaction can modify data at a time to prevent conflicts. 31. What is the purpose of the PROJECT operation in relational algebra? A) Combine rows from different tables. B) Sort the table in ascending order. C) Filter rows based on a condition. D) Remove unwanted columns from a table. Show Answer Correct Answer: D) Remove unwanted columns from a table. 32. Communication is established with MySQL using A) SQL. B) Network calls. C) Java. D) API's. Show Answer Correct Answer: A) SQL. 33. Which is not a feature of database software? A) Queries. B) Cropping. C) Tables. D) Filters. Show Answer Correct Answer: B) Cropping. 34. Which of the following is a fundamental relational algebra operation? A) Update. B) Join. C) Aggregate. D) Project. Show Answer Correct Answer: D) Project. 35. A database for a blog stores posts and comments. A single post can have MANY comments, but each comment belongs to ONLY ONE post. To model this, a POSTS table with PostID and a COMMENTS table with CommentID and a PostID foreign key are created. This database design is an example of what kind of relationship? A) One-to-one (1:1). B) A composite relationship. C) One-to-many (1:M). D) Many-to-many (M:N). Show Answer Correct Answer: C) One-to-many (1:M). 36. The ..... rule specifies that an entity instance of a supertype is allowed not to belong to any subtype. A) Semi-specialization. B) Partial specialization. C) Disjointness. D) Total specialization. Show Answer Correct Answer: B) Partial specialization. 37. Data warehouses are used for real-time data processing. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 38. Which additional relational algebra operation is used to combine rows from two tables? A) Project. B) Union. C) Intersect. D) Join. Show Answer Correct Answer: D) Join. 39. Log (Journal):A file that records all ..... activity. A) User. B) Network. C) Transaction. D) System. Show Answer Correct Answer: C) Transaction. 40. In the context of ACID properties, what does "Atomicity" primarily ensure? A) Data is permanently stored. B) Transactions are completed entirely or not at all. C) Concurrent transactions do not interfere. D) Database remains in a consistent state. Show Answer Correct Answer: B) Transactions are completed entirely or not at all. 41. Which of the following methods enforce data integrity. A) Constraints. B) Triggers. C) Procedure. D) Both a and b. Show Answer Correct Answer: D) Both a and b. 42. Which one of the following types of database schema is used for organizing data in single, two dimensional displays? A) Relational model. B) Network model. C) Hierarchical model. D) Flat model. Show Answer Correct Answer: D) Flat model. 43. Which key is a combination of two or more attributes that uniquely identify a row? A) Super key. B) Candidate key. C) Composite key. D) Foreign key. Show Answer Correct Answer: C) Composite key. 44. ..... :Preventing discrimination in data use. A) Transparency. B) Privacy. C) Accuracy. D) Fairness. Show Answer Correct Answer: D) Fairness. 45. What is a primary key constraint? A) A rule that defines data types. B) A rule that links tables. C) A rule that ensures uniqueness. D) A rule that allows null values. Show Answer Correct Answer: C) A rule that ensures uniqueness. 46. Which of the following SQL statements is used to delete specific records from a table? A) DELETE. B) REMOVE. C) ERASE. D) DROP. Show Answer Correct Answer: A) DELETE. 47. What is an example of a multi-value attribute? A) Age. B) Phone numbers. C) Name. D) Address. Show Answer Correct Answer: B) Phone numbers. 48. RDBMS supports horizontal scaling easily. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 49. Which of the following is NOT a type of DBMS? A) Hierarchical DBMS. B) Network DBMS. C) Linear DBMS. D) Relational DBMS. Show Answer Correct Answer: C) Linear DBMS. 50. What are the advantages of using a database system over a file system? A) Limited data sharing capabilities. B) Inflexible data formats. C) Advantages of using a database system over a file system include structured data management, support for complex queries, data integrity, concurrent access, efficient data retrieval, and enhanced security. D) Slower data processing speeds. Show Answer Correct Answer: C) Advantages of using a database system over a file system include structured data management, support for complex queries, data integrity, concurrent access, efficient data retrieval, and enhanced security. 51. Which topology the failure one computer affects the entire network? A) Star. B) Bus. C) Mesh. D) Ring. Show Answer Correct Answer: D) Ring. 52. When the values in one or more attributes being used as a foreign key must exist in another set of one or more attributes in another table, we have created a ..... A) Referential integrity constraint. B) Transitive dependency. C) Primary key. D) Partial dependency. Show Answer Correct Answer: A) Referential integrity constraint. 53. What are some security measures provided by a DBMS? A) Usernames and passwords. B) Access rights. C) Encryption of data. D) All of the above. Show Answer Correct Answer: D) All of the above. 54. Which of the following is not true about the ALTER TABLE statement? A) It can add a new column. B) It can define a default value for the new column. C) It can add a new row. D) It can modify existing columns. Show Answer Correct Answer: C) It can add a new row. 55. Which DBMS allows Pinterest to store and analyze user engagement data? A) PostgreSQL. B) Snowflake. C) Cassandra. D) HBase. Show Answer Correct Answer: D) HBase. 56. Outline the steps involved in the database design process. A) Data Entry, Data Processing, Data Analysis. B) The steps involved in the database design process are:Requirements Gathering, Conceptual Design, Logical Design, Physical Design, Implementation, Testing, and Maintenance. C) Backup, Recovery, Data Migration. D) User Interface Design, System Testing, Deployment. Show Answer Correct Answer: B) The steps involved in the database design process are:Requirements Gathering, Conceptual Design, Logical Design, Physical Design, Implementation, Testing, and Maintenance. 57. Which of the following is a characteristic of the relational model? A) Uses tables to represent data. B) Uses hierarchical structures. C) Uses flat files. D) Uses object-oriented programming. Show Answer Correct Answer: A) Uses tables to represent data. 58. In the context of a database, what is a "view" ? A) A graphical representation of data. B) A data input form. C) A virtual table based on the result of a SELECT query. D) A backup copy of the database. Show Answer Correct Answer: C) A virtual table based on the result of a SELECT query. 59. Which of the following is not the advantage of database? A) Reduce Data Redundancy. B) Sharing of Data. C) Data Security. D) Increase Data Inconsistency. Show Answer Correct Answer: D) Increase Data Inconsistency. 60. What is the purpose of data redundancy in a database? A) To reduce data storage space. B) To enhance data retrieval speed. C) To ensure data consistency. D) To improve data integrity. Show Answer Correct Answer: D) To improve data integrity. ← PreviousNext →Related QuizzesScience QuizzesClass 12 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 8 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books