Database Management System (DBMS)
MCQs – Set 2 Another 50 Fresh Questions with 4 Options
1. Which of the following is a disadvantage of DBMS?
A) Data sharing
B) Data redundancy control
C) High cost
D) Data security
Answer: C) High cost
2. What is the smallest unit of data in a database?
A) Field
B) Record
C) Table
D) Database
Answer: A) Field
3. Which command is used to remove all records from a table?
A) DROP
B) DELETE
C) TRUNCATE
D) REMOVE
Answer: C) TRUNCATE (Note: TRUNCATE is faster as it doesn’t log individual deletions)
4. A relation in database is also known as:
A) Table
B) Tuple
C) Attribute
D) Schema
Answer: A) Table
5. Which normal form removes partial dependency?
A) 1NF
B) 2NF
C) 3NF
D) BCNF
Answer: B) 2NF
6. Which normal form removes transitive dependency?
A) 2NF
B) 3NF
C) 4NF
D) 5NF
Answer: B) 3NF
7. What is BCNF?
A) Boyce-Codd Normal Form
B) Basic Candidate Normal Form
C) Binary Candidate Normal Form
D) Backup Candidate Normal Form
Answer: A) Boyce-Codd Normal Form
8. Which SQL statement is used to create a new database?
A) CREATE DATABASE
B) NEW DATABASE
C) MAKE DATABASE
D) ADD DATABASE
Answer: A) CREATE DATABASE
9. What does the COMMIT command do?
A) Saves changes permanently
B) Undoes changes
C) Rolls back changes
D) Deletes changes
Answer: A) Saves changes permanently
10. What does ROLLBACK command do?
A) Saves transaction
B) Undoes uncommitted changes
C) Creates backup
D) Deletes table
Answer: B) Undoes uncommitted changes
11. Which is an example of a one-to-many relationship?
A) Student and Roll No
B) Department and Employees
C) Employee and Employee ID
D) Person and Aadhar
Answer: B) Department and Employees
12. What is Cardinality in database?
A) Number of relationships
B) Number of tuples
C) Number of attributes
D) Number of tables
Answer: A) Number of relationships
13. Which is a Data Dictionary?
A) Metadata about database
B) Actual data
C) Backup fil
D) Log file
Answer: A) Metadata about database
14. What is a Trigger in DBMS?
A) Automatic action executed in response to an event
B) Manual command
C) Backup tool
D) Query optimizer
Answer: A) Automatic action executed in response to an event
15. Which of the following is a procedural language extension of SQL?
A) PL/SQL B) T-SQL C) Both A and B D) None Answer: C) Both A and B
16. What is the purpose of GRANT command?
A) Give permission to user
B) Revoke permission
C) Create user
D) Delete user
Answer: A) Give permission to user
17. What is the purpose of REVOKE command?
A) Give permission
B) Remove permission
C) Create table
D) Drop table
Answer: B) Remove permission
18. Which clause is used with aggregate functions?
A) WHERE
B) HAVING
C) FROM
D) SELECT
Answer: B) HAVING
19. What is an Index?
A) Data structure to improve search speed
B) Type of table
C) Backup copy
D) Log file
Answer: A) Data structure to improve search speed
20. Which is not a type of database integrity?
A) Entity Integrity
B) Referential Integrity
C) Domain Integrity
D) File Integrity
Answer: D) File Integrity
21. What is a Stored Procedure?
A) Pre-compiled SQL code
B) Simple query
C) Backup file
D) View
Answer: A) Pre-compiled SQL code
22. Which JOIN returns all records from left table?
A) INNER JOIN
B) LEFT JOIN
C) RIGHT JOIN
D) FULL JOIN
Answer: B) LEFT JOIN
23. Which JOIN returns all records from both tables?
A) LEFT JOIN
B) RIGHT JOIN
C) FULL OUTER JOIN
D) INNER JOIN
Answer: C) FULL OUTER JOIN
24. What is Denormalization?
A) Adding redundancy to improve performance
B) Removing redundancy
C) Creating new tables
D) Deleting tables
Answer: A) Adding redundancy to improve performance
25. Which is a NoSQL database type?
A) Document-oriented
B) Key-Value
C) Graph
D) All of the above
Answer: D) All of the above
26. What does ACID stand for?
A) Atomicity, Consistency, Isolation, Durability
B) Accuracy, Consistency, Integrity, Durability
C) Atomicity, Concurrency, Isolation, Durability
D) Accuracy, Concurrency, Isolation, Durability
Answer: A) Atomicity, Consistency, Isolation, Durability
27. What is Concurrency Control?
A) Managing simultaneous transactions
B) Backing up data
C) Creating tables
D) Indexing
Answer: A) Managing simultaneous transactions
28. What is a Deadlock?
A) Two or more transactions waiting for each other
B) Slow query
C) Data loss
D) Backup failure
Answer: A) Two or more transactions waiting for each other
29. Which command changes the structure of a table?
A) ALTER TABLE
B) MODIFY TABLE
C) UPDATE TABLE
D) CHANGE TABLE
Answer: A) ALTER TABLE
30. What is a Cursor in DBMS?
A) Pointer to traverse result set row by row
B) Mouse pointer
C) Chart tool
D) Backup pointer
Answer: A) Pointer to traverse result set row by row
31. Which is a popular commercial DBMS?
A) Oracle
B) Microsoft SQL Server
C) IBM DB2 D) All of the above
Answer: D) All of the above
32. What is Data Mining?
A) Extracting useful patterns from large data
B) Storing data
C) Deleting data
D) Backing up data
Answer: A) Extracting useful patterns from large data
33. What is OLAP?
A) Online Analytical Processing
B) Online Application Processing
C) Offline Analytical Processing
D) Online Advanced Processing
Answer: A) Online Analytical Processing
34. What does the DISTINCT keyword do?
A) Removes duplicate records
B) Adds duplicate records
C) Sorts records
D) Groups records Answer: A) Removes duplicate records
35. Which is the correct order of SQL clauses?
A) SELECT → FROM → WHERE → GROUP BY → HAVING → ORDER BY
B) FROM → SELECT → WHERE → ORDER BY
C) SELECT → WHERE → FROM
D) WHERE → SELECT → FROM
Answer: A) SELECT → FROM → WHERE → GROUP BY → HAVING → ORDER BY
36. What is a Super Key?
A) Set of attributes that uniquely identify a tuple
B) Primary key only
C) Foreign key only
D) Candidate key only
Answer: A) Set of attributes that uniquely identify a tuple
37. What is an Alternate Key?
A) Candidate key not selected as primary key
B) Foreign key
C) Composite key
D) Secondary key
Answer: A) Candidate key not selected as primary key
38. What is a Composite Key?
A) Key made of two or more attributes
B) Single attribute key
C) Foreign key
D) Super keys
Answer: A) Key made of two or more attributes
39. Which is not a database security method?
A) Encryption
B) Authentication
C) Authorization
D) Normalization
Answer: D) Normalization
40. What is Backup in DBMS?
A) Copy of database for recovery
B) Duplicate data
C) Temporary storage
D) Index file
Answer: A) Copy of database for recovery
41. What does the BETWEEN operator do?
A) Selects values within a range
B) Selects exact value
C) Excludes values
D) Joins tables
Answer: A) Selects values within a range
42. Which is a valid aggregate function?
A) SUM()
B) MAX()
C) MIN()
D) All of the above
Answer: D) All of the above
43. What is a Wildcard character in SQL?
A) % and _
B) * and ?
C) # and &
D) @ and $
Answer: A) % and _
44. What does the LIKE operator do?
A) Pattern matching
B) Exact matching
C) Range checking
D) Joining
Answer: A) Pattern matching
45. What is Database Recovery?
A) Restoring database after failure
B) Backing up database
C) Normalizing database
D) Indexing database
Answer: A) Restoring database after failure
46. Which is a type of SQL subquery?
A) Correlated subquery B) Nested subquery
C) Both A and B
D) None
Answer: C) Both A and B
47. What is the function of CHECK constraint?
A) To limit the value range in a column
B) To create primary key
C) To create foreign key
D) To delete records
Answer: A) To limit the value range in a column
48. What is a Package in DBMS?
A) Group of related procedures and functions
B) Single procedure
C) Table
D) View Answer: A) Group of related procedures and functions
49. Which is the latest trend in databases?
A) Cloud Databases
B) Big Data databases
C) Distributed Databases
D) All of the above
Answer: D) All of the above
50. What is the main goal of a DBMS?
A) To provide efficient data management, security, and integrity
B) To create documents
C) To make presentations
D) To play games
Answer: A) To provide efficient data management, security, and integrity
Database Management System (DBMS) Set 2
