CPS 510 Final Exam Actual Questions and Answers Verified 100% Correct Latest Update

CPS 510 Final Exam Actual Questions and Answers Verified 100% Correct Latest Update Q1: Which of the following commands will add a column email to an existing table users? a) ALTER TABLE users ADD email VARCHAR(100); b) MODIFY TABLE users ADD email VARCHAR(100); c) ADD COLUMN email VARCHAR(100) TO users; d) ALTER users ADD email VARCHAR(100); - ANSWER -Correct ANSWER: a Q3: Given a table employees with columns name and department, what does the following query do? SELECT DISTINCT department FROM employees; a) Retrieves the count of employees in each department. b) Retrieves all departments, including duplicates. c) Retrieves unique department names without duplicates. d) Retrieves all employee names in each department. - ANSWER -Correct ANSWER: c Q2: If the functional dependency A - B holds, which of the following is true? a) B can determine A. b) A uniquely determines B. c) A and B are independent. d) A depends on B. - ANSWER -Correct ANSWER: b Q4: What is the primary purpose of the JOIN clause in SQL? a) To create new tables dynamically. b) To delete rows from multiple tables. c) To filter data from a single table. d) To combine data from two or more tables based on a related column. - ANSWER -Correct ANSWER: d Q5: Which of the following ensures that a database transaction is durable? a) The transaction updates are saved to persistent storage before completion. b) The transaction involves no updates. c) The transaction is atomic. d) The transaction is isolated from other transactions. - ANSWER -Correct ANSWER: a Q6: Which SQL clause is used to filter groups after grouping with GROUP BY? a) FILTER b) GROUP BY c) WHERE d) HAVING - ANSWER -Correct ANSWER: d Q7: If a relation has a multivalued dependency, which normal form is it not in? a) 4NF b) 3NF c) 2NF d) 1NF - ANSWER -Correct ANSWER: a Q8: Which of the following queries will count the number of rows in the table students? a) SELECT SUM() FROM students; b) SELECT ROWS() FROM students; c) SELECT COUNT() FROM students; d) SELECT TOTAL() FROM students; - ANSWER -Correct ANSWER: c Q9: What does the ON DELETE CASCADE action do in a foreign key constraint? a) Deletes rows in the referencing table when a referenced row is deleted. b) Sets the referencing foreign key column to its default value when the referenced row is deleted. c) Prevents deletion of referenced rows. d) Sets the referencing foreign key column to NULL when the referenced row is deleted. - ANSWER -Correct ANSWER: a Q20: What is the output of the following relational algebra operation? R(A, B) ∪ S(A, B) a) All tuples that are in either R or S, or both, with duplicates removed. b) All tuples that are in R but not in S. c) All tuples that are common to R and S. d) All tuples that are in S but not in R. - ANSWER -Correct ANSWER: a Q21: What is the purpose of the PRIMARY KEY constraint in a table? a) To allow duplicate rows. b) To enforce unique values and prevent NULL values. c) To enable fast searching in the table. d) To define a default value for a column. - ANSWER -Correct ANSWER: b Q22: Which SQL command removes all data from a table but keeps its structure? a) DELETE b) DROP c) TRUNCATE d) ALTER - ANSWER -Correct ANSWER: c Q23: What is the default sorting order when using the ORDER BY clause in SQL? a) Descending b) Random c) Ascending d) Lexicographical - ANSWER -Correct ANSWER: c Q24: Which of the following queries retrieves all rows where the salary is between 50000 and 100000? a) SELECT * FROM employees WHERE salary = 50000 AND salary = 100000; b) SELECT * FROM employees WHERE salary BETWEEN 50000 AND 100000; c) SELECT * FROM employees WHERE salary IN (50000, 100000); d) Both a and b. - ANSWER -Correct ANSWER: d Q25: Which of the following describes a foreign key? a) A column used to identify a unique row in the same table. b) A column or set of columns used to enforce a link between the data in two tables.