This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Computer Science > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 21 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 21 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the Super key? A) A superkey is a group of single or multiple keys which identifies rows in a table. B) A super key may have additional attributes that are not needed for unique identification. C) Both A and B. D) None of the above. Show Answer Correct Answer: C) Both A and B. 2. What is the function of the DROP command in SQL? A) To add new data. B) To update existing data. C) To select specific data. D) To delete a table or database. Show Answer Correct Answer: D) To delete a table or database. 3. Database management systems, operating systems, applications and utilities are all examples of ..... A) Software. B) Hardware. C) Computer infrastructure. D) Input and output. Show Answer Correct Answer: A) Software. 4. Which one of the following programing models is the most recent concept that used to write dynamic program? A) Object oriented programming. B) Functional programing. C) Imperative programing. D) Logic programming. Show Answer Correct Answer: A) Object oriented programming. 5. In a 1:N relationship, how is it represented in a relational schema? A) By placing the primary key of the parent in the child table. B) By creating a separate table for each entity. C) By using a composite key. D) By merging both tables into one. Show Answer Correct Answer: A) By placing the primary key of the parent in the child table. 6. What does the COUNT function do in SQL? A) It retrieves unique values from a column. B) It filters records based on specified conditions. C) It sorts the result set in ascending order. D) It counts the number of rows in a table. Show Answer Correct Answer: D) It counts the number of rows in a table. 7. What are the advantages of using stored procedures for query optimization? A) Stored procedures improve performance through pre-compilation, reduced network traffic, and better execution plan reuse. B) Stored procedures eliminate the need for indexing completely. C) Stored procedures increase data redundancy and complexity. D) Stored procedures require more manual coding for each query. Show Answer Correct Answer: A) Stored procedures improve performance through pre-compilation, reduced network traffic, and better execution plan reuse. 8. Which one of the following OSI layer is responsible if the website loads slowly but the network connection is stable? A) Transport layer. B) Application layer. C) Physical layer. D) Network layer. Show Answer Correct Answer: B) Application layer. 9. How does denormalization affect database performance? A) Denormalization eliminates redundancy in the database. B) Denormalization can improve read performance but may negatively impact write performance due to increased redundancy. C) Denormalization has no effect on database performance. D) Denormalization only improves write performance without affecting reads. Show Answer Correct Answer: B) Denormalization can improve read performance but may negatively impact write performance due to increased redundancy. 10. How do transactions ensure data consistency in a DBMS? A) Transactions are only for data retrieval, not consistency. B) Transactions rely solely on backup systems. C) Transactions ensure data consistency through ACID properties. D) Data consistency is achieved through user permissions. Show Answer Correct Answer: C) Transactions ensure data consistency through ACID properties. 11. Which type of user would be responsible for managing the database schema? A) System designer. B) Database administrator. C) End user. D) Application developer. Show Answer Correct Answer: B) Database administrator. 12. A file system suffers from which of the following limitations? A) Data inconsistency. B) Lack of data redundancy. C) Easy data sharing. D) Simplicity of structure. Show Answer Correct Answer: A) Data inconsistency. 13. Which DBMS function is responsible for storing data and related data entry forms, report definitions, etc.? A) Data encryption. B) Data storage management. C) Data analysis. D) Data visualization. Show Answer Correct Answer: B) Data storage management. 14. Sistem ..... yang selalu meningkatkan kebutuhan perubahan tiap waktu. A) Proteksi. B) Maintain. C) Reset. D) Format. Show Answer Correct Answer: B) Maintain. 15. What is TRUE about Relational Data Model? A) Tables are used in relational models to represent data and the relationships between them. B) Edgar F. Codd presented this model in 1969. C) Most commercial data processing applications use the relational data model. D) All of the above. Show Answer Correct Answer: D) All of the above. 16. What is the difference between a unique constraint and a primary key? A) A primary key can have duplicate values, while a unique constraint cannot. B) A primary key cannot be null and uniquely identifies records, while a unique constraint can allow nulls and ensures uniqueness. C) Both primary keys and unique constraints can be null. D) A unique constraint is used for foreign keys, while a primary key is not. Show Answer Correct Answer: B) A primary key cannot be null and uniquely identifies records, while a unique constraint can allow nulls and ensures uniqueness. 17. Explain the concept of foreign keys and their purpose. A) Foreign keys are used to enforce referential integrity between tables in a relational database. B) Foreign keys are primarily for data encryption. C) Foreign keys are used to create indexes on tables. D) Foreign keys are used to store large binary files. Show Answer Correct Answer: A) Foreign keys are used to enforce referential integrity between tables in a relational database. 18. What is a distributed database? A) A database that cannot be customized. B) A single logical database spread across multiple locations. C) A database stored in a single location. D) A database that only supports local access. Show Answer Correct Answer: B) A single logical database spread across multiple locations. 19. What is the E-R model used for? A) The E-R model is used for web development. B) The E-R model is used for graphic design. C) The E-R model is used for project management. D) The E-R model is used for database design and visualization. Show Answer Correct Answer: D) The E-R model is used for database design and visualization. 20. SELECT dept ..... name, ID, avg (salary)FROM instructorGROUP BY dept ..... name;This statement IS erroneous because A) Avg(salary) should not be selected. B) Dept id should not be used in group by clause. C) Group by clause is not valid in this query. D) Misplaced group by clause. Show Answer Correct Answer: B) Dept id should not be used in group by clause. 21. To remove a table structure from an SQL database, we use the ..... command. A) Drop table. B) Purge. C) Remove. D) Delete. Show Answer Correct Answer: A) Drop table. 22. Why is it only possible to access database files through the DBMS? A) Because the DBMS provides security and structure for accessing data. B) Because the files are stored in a cloud server. C) Because the database files are encrypted by default. D) Because the DBMS is a physical storage device. Show Answer Correct Answer: A) Because the DBMS provides security and structure for accessing data. 23. Which of the following will help to maintain unique record in the table? A) Primary Key. B) Foreign Key. C) Composite Key. D) Alternate Key. Show Answer Correct Answer: A) Primary Key. 24. Server Role:Stores data and runs the ..... A) CPU. B) DBMS. C) OS. D) RAM. Show Answer Correct Answer: B) DBMS. 25. Which of the following are valid levels of access? A) Read and change. B) Read only, edit, delete and append. C) Administrator and change. D) None of the above. Show Answer Correct Answer: B) Read only, edit, delete and append. 26. The following are functions of a DBMS except A) Creating database. B) Processing data. C) Creating and processing forms. D) Administrating database. Show Answer Correct Answer: C) Creating and processing forms. 27. What does local autonomy in a distributed database refer to? A) The need for constant data replication. B) The inability to manage local databases. C) The ability to operate independently when connections fail. D) The requirement to always connect to a central server. Show Answer Correct Answer: C) The ability to operate independently when connections fail. 28. Who developed the first database management system? A) Charles Bachman. B) Larry Page. C) Steve Jobs. D) Bill Gates. Show Answer Correct Answer: A) Charles Bachman. 29. What is the purpose of the SELECT operation in relational algebra? A) Add new records to a table. B) Filter rows based on a condition. C) Sort the table in ascending order. D) Combine rows from different tables. Show Answer Correct Answer: B) Filter rows based on a condition. 30. If user A is using a single-user database, what must users B and C do? A) They can access the database at the same time. B) They must wait until user A is done. C) They can view but not edit the database. D) They can edit the database remotely. Show Answer Correct Answer: B) They must wait until user A is done. 31. What happens to the foreign key in a binary relationship with total participation constraint? A) It acquires NOT NULL constraint. B) It becomes a primary key. C) It can be null. D) It is removed. Show Answer Correct Answer: A) It acquires NOT NULL constraint. 32. What does the SQL LIKE operator do? A) Compares numeric values. B) Sorts results. C) Matches a specified pattern in a column. D) Groups results. Show Answer Correct Answer: C) Matches a specified pattern in a column. 33. How does method overloading differ from method overriding? A) Overloading is defining methods with the same name in different classes, while overriding is defining methods with the same name in the same class. B) Overloading requires final methods, while overriding does not. C) Overloading changes the method signature, while overriding keeps the method signature the same. D) Overloading requires inheritance, whereas overriding does not. Show Answer Correct Answer: C) Overloading changes the method signature, while overriding keeps the method signature the same. 34. Which of the following is an example of a hierarchical model? A) Online Shopping Cart. B) Oracle DB. C) Excel Spreadsheet. D) Organizational Chart. Show Answer Correct Answer: D) Organizational Chart. 35. What is horizontal partitioning? A) Placing some rows of a relation at one site. B) Creating multiple copies of the entire database. C) Storing all data in a single location. D) Distributing columns of a relation among different sites. Show Answer Correct Answer: A) Placing some rows of a relation at one site. 36. You are a database administrator for a large company with multiple departments. Each department needs a separate view of the employee data, showing only relevant information (e.g., HR sees salary, a project manager sees project assignments). Which of the following components of the three-schema architecture would you use to implement these specific views? A) Conceptual Schemas. B) Internal Schemas. C) External Schemas. D) Database Instances. Show Answer Correct Answer: C) External Schemas. 37. One or more very large databases containing both detailed and summarized data for a number of years that is used for analysis rather than transaction processing. A) Data warehouse. B) Database. C) Data Sharing. D) Data Mining. Show Answer Correct Answer: A) Data warehouse. 38. What is the history of the first commercially available relational database management system (RDBMS)? A) Oracle. B) IBM DB2. C) MySQL. D) Microsoft SQL Server. Show Answer Correct Answer: A) Oracle. 39. Which of the following is not a DML command? A) Delete. B) Update. C) Truncate. D) Insert. Show Answer Correct Answer: C) Truncate. 40. What are the 4 properties of a transaction? A) Atomicity, Concurrency, Isolation, Durability. B) Atomicity, Consistency, Isolation, Durability. C) Atomicity, Consistency, Isolation, Concurrency. D) Concurrency, Isolation, Durability, Consistency. Show Answer Correct Answer: B) Atomicity, Consistency, Isolation, Durability. 41. What is the role of a database designer? A) To write software programs. B) To manage user access. C) To create video games. D) To identify data to be stored. Show Answer Correct Answer: D) To identify data to be stored. 42. When identifying the parts of the packaged data model that apply to your organization, one should first start with: A) Primary keys. B) Relationships. C) Entities. D) Attributes. Show Answer Correct Answer: C) Entities. 43. Which SQL keyword is used to sort the result set? A) ARRANGE BY. B) GROUP BY. C) SORT BY. D) ORDER BY. Show Answer Correct Answer: D) ORDER BY. 44. In order to maintain transactional integrity and database consistency, what technology does a DBMS deploy? A) Triggers. B) Cursors. C) Pointers. D) Locks. Show Answer Correct Answer: D) Locks. 45. Which of the following is a valid SQL constraint? A) INDEX. B) LIST. C) VALUE KEY. D) UNIQUE. Show Answer Correct Answer: D) UNIQUE. 46. Which of the following is not a type of MS Access database object? A) Table. B) Modules. C) Form. D) Worksheets. Show Answer Correct Answer: D) Worksheets. 47. An entity cluster is: A) A formal method for specifying attributes of related entities. B) A set of one or more entity types and associated relationships grouped into a single abstract entity type. C) A useful way to present data for a small and fairly simple organization. D) A way of developing more granular views of the data model. Show Answer Correct Answer: B) A set of one or more entity types and associated relationships grouped into a single abstract entity type. 48. A manager has requested a list of all products over $ 100 and in size "Large" . How would this information be retrieved? A) Filter. B) Sort Descending. C) Sort Ascending. D) Find. Show Answer Correct Answer: A) Filter. 49. What does the term 'data integrity' refer to in a database? A) Ensuring data is accurate and consistent. B) Storing data in multiple formats. C) Increasing data redundancy. D) Limiting data access to authorized users. Show Answer Correct Answer: A) Ensuring data is accurate and consistent. 50. Which one will delete the table data as well as table structure? A) DELETE. B) DROP. C) All the above. D) None of the above. Show Answer Correct Answer: B) DROP. 51. What is an advantage of using joins in a DBMS? A) They combine related tables on keys. B) They reduce data redundancy. C) They simplify file storage. D) They eliminate the need for backups. Show Answer Correct Answer: A) They combine related tables on keys. 52. In terms of databases, what does consistency mean? A) All data inputted follows the same format. B) All users have the same view of data. C) The data is the same no matter who views it. D) None of the above. Show Answer Correct Answer: B) All users have the same view of data. 53. Which SQL keyword is used to ensure no duplicate rows are returned? A) DIFFERENT. B) DISTINCT. C) UNIQUE. D) SPECIFIC. Show Answer Correct Answer: B) DISTINCT. 54. Which keyword is used to declare a static member in Java? A) Static. B) Constant. C) Final. D) Global. Show Answer Correct Answer: A) Static. 55. In a relational data model, what do rows represent? A) Tables. B) Schemas. C) Attributes. D) Records. Show Answer Correct Answer: D) Records. 56. Which of the following best describes a primary key in a database table? A) A field that stores images. B) A unique identifier for each record in a table. C) A field used for sorting data only. D) A field that can contain duplicate values. Show Answer Correct Answer: B) A unique identifier for each record in a table. 57. 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. 58. 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. 59. Database administrators want to improve the performance of a complex SQL query. Which technique should they consider first? A) Reducing data redundancy. B) Increasing the number of indexes. C) Adding more tables to the database. D) Using query optimization techniques. Show Answer Correct Answer: D) Using query optimization techniques. 60. Which operation is NOT part of CRUD? A) Update. B) Create. C) Read. D) Sort. Show Answer Correct Answer: D) Sort. ← 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