This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Computer Science > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 2 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 2 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Differentiate between INNER JOIN and OUTER JOIN. A) INNER JOIN can return unmatched rows; OUTER JOIN cannot. B) INNER JOIN is used for aggregating data; OUTER JOIN is used for filtering data. C) INNER JOIN returns all rows from both tables; OUTER JOIN returns only matched rows. D) INNER JOIN returns matched rows; OUTER JOIN returns all rows from one table and matched rows from the other. Show Answer Correct Answer: D) INNER JOIN returns matched rows; OUTER JOIN returns all rows from one table and matched rows from the other. 2. What is the function of the HAVING clause in SQL? A) To create a new index on a table. B) To filter records after aggregation has been performed. C) To join multiple tables together. D) To sort the result set in descending order. Show Answer Correct Answer: B) To filter records after aggregation has been performed. 3. What is the primary purpose of metadata? A) To manage database security. B) To perform data analysis. C) To store user data. D) To describe data properties. Show Answer Correct Answer: D) To describe data properties. 4. Explain the concept of data integrity in database systems. A) Data integrity ensures the accuracy and consistency of data in a database. B) Data integrity is about the physical storage of data on disk drives. C) Data integrity ensures the availability of data during system failures. D) Data integrity refers to the speed of data retrieval in databases. Show Answer Correct Answer: A) Data integrity ensures the accuracy and consistency of data in a database. 5. What is a characteristic of a single-user database? A) It allows multiple users to access the database simultaneously. B) It supports only one user at a time. C) It is always stored on a server. D) It requires internet access to function. Show Answer Correct Answer: B) It supports only one user at a time. 6. Two-Phase Locking (2PL):A protocol that ensures serializable schedules using ..... A) Caches. B) Timestamps. C) Buffers. D) Locks. Show Answer Correct Answer: D) Locks. 7. What does the rename operation do in relational algebra? A) Deletes a relation. B) Combines relations. C) Creates a new relation. D) Changes the name of a relation. Show Answer Correct Answer: D) Changes the name of a relation. 8. What characterises Big Data management in modern databases? A) Limited storage capacity. B) Handling vast data volumes efficiently. C) Slow processing speeds. D) Restricted data types. Show Answer Correct Answer: B) Handling vast data volumes efficiently. 9. What is the purpose of the SELECT statement in SQL? A) To create a new database. B) To retrieve data from one or more tables. C) To delete records from a table. D) To update existing records in a table. Show Answer Correct Answer: B) To retrieve data from one or more tables. 10. A distributed database system is experiencing slow query performance. What is the most likely reason? A) Using a Relational Database Management System (RDBMS) instead of a NoSQL database. B) High network latency and inefficient query execution. C) Too many foreign key constraints. D) Lack of data replication. Show Answer Correct Answer: B) High network latency and inefficient query execution. 11. What is the purpose of the ORDER BY clause? A) To group data. B) To sort data. C) To join tables. D) To filter data. Show Answer Correct Answer: B) To sort data. 12. What is the purpose of database normalization? A) To increase data redundancy for faster access. B) To enhance the visual representation of data in reports. C) The purpose of database normalization is to minimize data redundancy and ensure data integrity. D) To simplify database queries by merging tables. Show Answer Correct Answer: C) The purpose of database normalization is to minimize data redundancy and ensure data integrity. 13. Commit:The successful completion of a transaction where all changes are ..... A) Rolled back. B) Permanently saved. C) Temporarily stored. D) Deleted. Show Answer Correct Answer: B) Permanently saved. 14. What is the primary purpose of a Database Management System? A) To perform data analysis. B) To design hardware systems. C) To manage and organize data. D) To create software applications. Show Answer Correct Answer: C) To manage and organize data. 15. Which company uses Firebase for live, real-time updates? A) Reddit. B) The New York Times. C) Coca-Cola. D) American Airlines. Show Answer Correct Answer: B) The New York Times. 16. Data software for working with the database A) DB. B) DBMS. C) BZ. D) None of the above. Show Answer Correct Answer: B) DBMS. 17. Which of the following is an example of a Relational DBMS? A) MongoDB. B) MySQL. C) Cassandra. D) Neo4j. Show Answer Correct Answer: B) MySQL. 18. What is the difference between a database and a database management system? A) A database is the data itself; a DBMS is the software that manages the database. B) A database is the software; a DBMS is the data itself. C) A database stores data; a DBMS is a type of hardware. D) A database is a collection of files; a DBMS is a programming language. Show Answer Correct Answer: A) A database is the data itself; a DBMS is the software that manages the database. 19. What is the role of a primary key in a relational database? A) A primary key is used to create indexes for faster data retrieval. B) A primary key is optional and can be left blank. C) A primary key uniquely identifies each record in a table and ensures that no duplicate entries exist. D) A primary key is used to encrypt data in the database. Show Answer Correct Answer: C) A primary key uniquely identifies each record in a table and ensures that no duplicate entries exist. 20. Which model organizes data in a tree-like structure with a single parent for each record? A) Relational Model. B) Object-Oriented Model. C) Hierarchical Model. D) Network Model. Show Answer Correct Answer: C) Hierarchical Model. 21. Which of the following refers to the number of tuples in a relation? A) Cardinality. B) Column. C) Key. D) Entity. Show Answer Correct Answer: A) Cardinality. 22. The subtype discriminator is a composite attribute when there is a(n): A) Partial specialization. B) Full specialization. C) Disjoint rule. D) Overlap rule. Show Answer Correct Answer: D) Overlap rule. 23. What is normalization in the context of a relational database? A) The process of designing a database to reduce redundancy. B) The process of optimizing queries. C) The process of adding new tables. D) The process of deleting old data. Show Answer Correct Answer: A) The process of designing a database to reduce redundancy. 24. How does a check constraint function in SQL? A) It ensures that all SQL commands are checked for errors before execution. B) It restricts the type of data that can be inserted into a table based on specific conditions. C) It checks and removes incorrect entries from a table automatically. D) It verifies user permissions before allowing data insertion. Show Answer Correct Answer: B) It restricts the type of data that can be inserted into a table based on specific conditions. 25. Which one of the following commands is used to modify a column inside a table? A) Drop. B) Set. C) Alter. D) Update. Show Answer Correct Answer: C) Alter. 26. What is a characteristic of naive users? A) Use SQL frequently. B) Familiar with DBMS. C) Depend on GUI simplicity. D) Design databases. Show Answer Correct Answer: C) Depend on GUI simplicity. 27. What is data independence? A) A database model. B) Changes in data structure without affecting other levels. C) A type of data. D) A programming language. Show Answer Correct Answer: B) Changes in data structure without affecting other levels. 28. In a multi-user database environment, what does "concurrency" primarily refer to? A) Database processing speed. B) Simultaneous execution of multiple transactions. C) Number of database servers. D) The number of users accessing the database. Show Answer Correct Answer: B) Simultaneous execution of multiple transactions. 29. Which of the following is a benefit of integrating a hospital's database management system with other health systems? A) Makes patient data less secure. B) Increases the workload of healthcare staff. C) Ensures real-time data exchange and reduces manual errors. D) Complicates the data retrieval process. Show Answer Correct Answer: C) Ensures real-time data exchange and reduces manual errors. 30. What does the 'D' in ACID stand for? A) Durability. B) Dependability. C) Decoupling. D) Data Integrity. Show Answer Correct Answer: A) Durability. 31. What is the role of a database engine? A) To create user interfaces. B) To manage hardware resources. C) To handle queries and data retrieval. D) To perform data entry tasks. Show Answer Correct Answer: C) To handle queries and data retrieval. 32. How does the size of a DBMS impact its efficiency? A) Smaller size results in higher costs. B) Larger size occupies more disk space and memory. C) Larger size leads to faster performance. D) Smaller size requires more memory to run efficiently. Show Answer Correct Answer: B) Larger size occupies more disk space and memory. 33. When a company needs a dynamic web application that interacts with a database and provides real-time updates. What combination of technologies should they use? A) JavaScript, AJAX, and a server-side language like PHP or Node.js. B) Static HTML files with no database. C) HTML, CSS, and JavaScript only. D) Only JavaScript and no backend. Show Answer Correct Answer: A) JavaScript, AJAX, and a server-side language like PHP or Node.js. 34. The main purpose of MS Access in agriculture is to: A) Create 3D crop models. B) Maintain and analyze agricultural data easily. C) Perform weather forecasting. D) Edit satellite images. Show Answer Correct Answer: B) Maintain and analyze agricultural data easily. 35. Which JOIN returns all rows from both tables, matching them where possible? A) FULL OUTER JOIN. B) INNER JOIN. C) LEFT JOIN. D) RIGHT JOIN. Show Answer Correct Answer: A) FULL OUTER JOIN. 36. Which command quickly locates the data is Access table? A) Locate. B) Edit. C) Search. D) Find. Show Answer Correct Answer: D) Find. 37. Explain the difference between a relational and a non-relational database. A) Relational databases store data in JSON format. B) Relational databases are only used for large datasets. C) Relational databases use structured tables and SQL, while non-relational databases use flexible formats and various query methods. D) Non-relational databases require SQL for data manipulation. Show Answer Correct Answer: C) Relational databases use structured tables and SQL, while non-relational databases use flexible formats and various query methods. 38. Which company uses SAP HANA to manage data from production lines? A) Mercedes-Benz. B) Reddit. C) Airbnb. D) Fitbit. Show Answer Correct Answer: A) Mercedes-Benz. 39. What is an advantage of role-based views in a DBMS? A) They are always accurate. B) They show different slices of data. C) They eliminate redundancy. D) They require no training. Show Answer Correct Answer: B) They show different slices of data. 40. Which level of data and process distribution would be most appropriate for a multinational company with offices and data centers in multiple countries? A) SPSD. B) MPSD. C) MPMD. D) None of the above. Show Answer Correct Answer: C) MPMD. 41. The candidate key that you choose to identify each row uniquely is called ..... A) Alternate key. B) Unique key. C) Super key. D) Primary key. Show Answer Correct Answer: D) Primary key. 42. Which term refers to data about data in a database? A) Schema. B) Metadata. C) Instance. D) Data dictionary. Show Answer Correct Answer: B) Metadata. 43. The ..... determines what values are stored in the table. A) Row. B) Column. C) Table. D) Record. Show Answer Correct Answer: B) Column. 44. Which of the following defines the structure of a relation that consists of a fixed set of attribute-domain pairs. A) Program. B) Instance. C) Schema. D) Super key. Show Answer Correct Answer: C) Schema. 45. What is the purpose of the "Varchar" data type in MariaDB? A) To store integers only. B) To store boolean values. C) To store variable-length strings up to a specified number of characters. D) To store fixed-length strings. Show Answer Correct Answer: C) To store variable-length strings up to a specified number of characters. 46. A unique identifying field. A) Boolean. B) Integer. C) Verification. D) Primary Key. Show Answer Correct Answer: D) Primary Key. 47. Which of the following best describes a centralized database architecture? A) All data are located at a single site. B) Data are distributed across several different sites. C) Data are stored only on personal computers. D) Data are only accessible by one user at a time. Show Answer Correct Answer: A) All data are located at a single site. 48. What is the ability to change a schema at one level without affecting the higher level schemas called? A) Data Independence. B) Mapping. C) Schema. D) None of the above. Show Answer Correct Answer: A) Data Independence. 49. What is the main advantage of using a DBMS over a traditional file system? A) It is easier to lose data. B) It provides better data security, integrity, and reduces data redundancy. C) It requires no technical knowledge. D) It is only suitable for small amounts of data. Show Answer Correct Answer: B) It provides better data security, integrity, and reduces data redundancy. 50. Empdt1(empcode, name, street, city, state, pincode).For any pincode, there is only one city and state. Also, for given street, city and state, there is just one pincode. In normalization terms, empdt1 is a relation in A) 1 NF only. B) 2 NF and hence also in 1 NF. C) 3NF and hence also in 2NF and 1NF. D) BCNF and hence also in 3NF, 2NF and 1NF. Show Answer Correct Answer: B) 2 NF and hence also in 1 NF. 51. Which characteristic distinguishes quantitative data from qualitative data? A) Complexity of collection. B) Storage requirements. C) Numerical nature. D) Processing speed. Show Answer Correct Answer: C) Numerical nature. 52. What is the purpose of a query optimizer in a DBMS? A) To store data. B) To improve query performance. C) To manage user access. D) To create backups. Show Answer Correct Answer: B) To improve query performance. 53. What is meant by less redundancy in DBMS? A) Less redundancy refers to having more data copies for safety. B) Less redundancy means minimizing duplicate data in a DBMS. C) Less redundancy means increasing data storage capacity. D) Less redundancy indicates a higher number of data entries. Show Answer Correct Answer: B) Less redundancy means minimizing duplicate data in a DBMS. 54. Which of the following gives a logical structure of the database graphically? A) Architectural representation. B) Entity diagram. C) Database diagram. D) Entity-relationship diagram. Show Answer Correct Answer: D) Entity-relationship diagram. 55. Describe the role of a database administrator (DBA). A) Creating marketing strategies for database products. B) Writing code for database queries. C) The role of a database administrator (DBA) includes managing, maintaining, and securing database systems. D) Designing user interfaces for applications. Show Answer Correct Answer: C) The role of a database administrator (DBA) includes managing, maintaining, and securing database systems. 56. A company currently uses spreadsheets for payroll. Which is the best reason to switch to a DBMS? A) DBMS is easier to install than Excel. B) DBMS prevents redundancy and ensures data consistency. C) DBMS requires no technical knowledge. D) DBMS eliminates all data errors automatically. Show Answer Correct Answer: B) DBMS prevents redundancy and ensures data consistency. 57. What is the purpose of the authorization manager in a DBMS? A) To ensure data integrity. B) To control user access to data. C) To manage data storage. D) To optimize query performance. Show Answer Correct Answer: B) To control user access to data. 58. What type of devices do straight-through cables connect? A) Switch to switch. B) Switch to hub. C) Computer to computer without any connectivity device. D) Computer to switch. Show Answer Correct Answer: B) Switch to hub. 59. Which of the following is a Data Model? A) Entity-Relationship model. B) Relational data model. C) Object-Based data model. D) All of the above. Show Answer Correct Answer: D) All of the above. 60. What does the Details view control allow a user to do? A) See one row at a time. B) Create new database tables. C) View multiple rows at once. D) Edit the database structure. Show Answer Correct Answer: A) See one row at a time. ← 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 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 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books