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UGC NET · PAPER 2

UGC NET Paper 2 Computer Science – Unit 4: Database Management Systems PYQ (June 2024 (Cancelled Exam))

9 questions · answer key at the end · updated 11 Oct 2026
Q45. Which of the following is/are true in case of tree locking (the tree protocol)?
A. It ensures shorter waiting times.
B. It ensures freedom from deadlock.
C. A transaction can lock data items earlier.
D. It does not ensure a greater amount of concurrency.
Choose the correct answer from the options given below:
  1. A and B Only
  2. C and D Only
  3. B and C Only
  4. A and D Only
Answer & explanation →
Q56. Which of the following statements is/are FALSE?
A. A user can assign privileges to any user on any relation.
B. A user can assign privileges to other users only on its own relations.
C. A system error that leads to access to a portion of the database is an example of a malicious attack.
D. Passwords themselves need to be secured from unauthorised access.
Choose the correct answer from the options given below:
  1. A and C Only
  2. A and B Only
  3. B and D Only
  4. B and C Only
Answer & explanation →
Q59. The techniques used to handle the phantom problem are:
A. Time stamping
B. Index locking
C. Predicate locking
D. Execution indexing
Choose the correct answer from the options given below:
  1. A and B Only
  2. B and C Only
  3. A and D Only
  4. C and D Only
Answer & explanation →
Q66. What will be the order of the typical steps when processing a high-level query?
A. Query optimizer
B. Runtime database processor
C. Scanning, parsing and validating
D. Query code generator
Choose the correct answer from the options given below:
  1. D, A, C, B
  2. C, A, D, B
  3. C, D, B, A
  4. D, C, B, A
Answer & explanation →

Directions (Q96–100): A company is implementing a new database system to manage its customer information. The database contains tables for customers, orders, products and sales representatives. Each customer can place multiple orders and each order can contain multiple products. Each order is associated with a specific sales representative who manages the account. The database is designed to improve efficiency in tracking sales and customer interactions.

Q96. Which SQL query retrieves the total number of orders placed by a specific customer?
  1. SELECT COUNT(*) AS total_orders FROM orders WHERE customer_id = [Customer_ID];
  2. SELECT COUNT(order_id) AS total_orders FROM orders WHERE customer_id = [Customer_ID];
  3. SELECT COUNT(DISTINCT order_id) AS total_orders FROM orders WHERE customer_id = [Customer_ID];
  4. SELECT SUM(order_id) AS total_orders FROM orders WHERE customer_id = [Customer_ID];
Answer & explanation →
Q97. Based on the passage, which of the following statements is true?
  1. Each customer can place only one order.
  2. Each sales representative can manage multiple customer accounts.
  3. Each order can be associated with only one product.
  4. The database does not include a table for products.
Answer & explanation →
Q98. Which of the following tables is most likely to have a foreign key referencing another table?
  1. Customers
  2. Orders
  3. Products
  4. Sales representatives
Answer & explanation →
Q99. Which SQL query retrieves the total number of distinct customers who have placed orders?
  1. SELECT COUNT(DISTINCT customer_id) AS total_customers FROM orders;
  2. SELECT COUNT(*) AS total_customers FROM customers;
  3. SELECT COUNT(DISTINCT order_id) AS total_customers FROM orders;
  4. SELECT COUNT(DISTINCT customer_id) AS total_customers FROM customers;
Answer & explanation →
Q100. Which of the following best describes the relationship between the 'orders' table and the 'customers' table?
  1. One-to-One
  2. One-to-Many
  3. Many-to-One
  4. Many-to-Many
Answer & explanation →

Answer key

  1. 45 – A
  2. 56 – A
  3. 59 – B
  4. 66 – B
  5. 96 – B
  6. 97 – B
  7. 98 – B
  8. 99 – A
  9. 100 – C