General MCQ for Database Management

1.

Which of the following inference rules for functional dependencies are correct?

1. |fA> BandA>C,thenA> BC

2. lfA>BC,thenA>BandA>C

3. |fA> B and DB>C,then DA>C

4.lfA>BandC>D.thenAC>BD

2. Which of the following statements is incorrect?

3. What do you mean by backflushing in the construction of a data warehouse?

4. Data dictionary can be used for which of the following options? 1. For f‌inding the location of the data. 2. For f‌inding the size of the storage disk. 3. For f‌inding the owner of the data.

5. What is the use of the TRUNCATE command in SQL?

6. Any user-defined Object in an Object model that is not a type of collection object is called a/an _.

7. Which of the following access control policies ensures a high degree of protection from malicious attacks?

8. An Object-oriented database stores persistent object(s) that is/are not shared among multiple applications or programs, in a permanent storage.

9. Which Of the given figures represents a weak entity as used in Entity-Relationship (ER) diagrams?

10. Consider a relation 'Book' with the following structure: book_id (Primary key) book_name book_title date_of_issue Which of the following relational algebra operations will return all the entries of book_id and book_title from the relation 'Book'?

11. Which of the following options is defined as the tendency to change the internal schema without affecting the conceptual schema?

12. Which of the following levels of a data storage virtualization technology involves block-level striping with distributed parity?

13. Which one of the given options is not a component of a storage manager in a database management system?

14. A database table must have only one primary key and one super key.

15. Which attributes is represented by the entity-relationship (E-R) diagram given in the image?

16. Suppose there are two relations: R1 and R2. If C1 and C2 are the selection conditions, and A1 and A2 are the attributes of the relation R1, then which of the given query transformations are correct? 1. 0C1 (0C1 (R1)) -> 0C2 (0C2 (R1)) 2. 0C1 (nA1 (R1)) -> nAl (0C1 (R1)) 3. 0C1 (R1 U R2) -> 0C1 (R1) U 0C1 (R2)

17. Which database security mechanisms is used to enforce multilevel security by classifying users and data into various security levels? 1. Mandatory security mechanisms 2. Discretionary security mechanisms

18. Which of the given options is targeted and focused on a single subset of an organization?

19. Which of the following relational algebra expressions represents the query that will f‌ind names of customers having an account balance of over Rs. 5.000?

20. How can a timestamp be implemented in a database?

21. Which of the following is NOT the correct syntax to write the REVOKE statement that is used to revoke a privilege on a table named, Employee from user2?

22. Consider a table titled 'StudentDetails' having the following attributes:

23. Database normalization is used to .

24. Which of the following relations is also called a snapshot relation?

25. Which of the following indexes in databases is usually dense?

26. What is the order of execution of operations during a pessimistic concurrency control technique?

27. A database system without concurrency control may cause:

28. Restriction of_ from the basic relational model has been removed in the nested relational model.

29. Which of the following statements about normal forms is/are true?