10. The ____ set operator will show all rows common to both tables A and B. (a) intersection (b) union (c) difference (d) product 11. Using the product operator, if table A has 2 rows and table B has 4 rows, the number of rows in the product of these two tables is: (a) 4. (b) 8. (c) 16. (d) 20. 12. Suppose relation R(A,B,C,D,E) has the following functional dependencies: A → B B → C BC → A A → D D → E Which of the following is not a key? (a) A (b) E (c) B (d) D (e) (b) and (d) 13. Consider a relation Q with five attributes L V O B Y. You are given the follwoing dependencies: L → V; VO → Y and YB → L. The number of superkeys of Q is: (not superkeys) (a).2 (b).3 (c),4 (d).5 Giáo Trình Cơ Sở Dữ Liệu Trang 97 Biên soạn : Phan Tấn Quốc- Trường Cao Đẳng Kỹ Thuật Cao Thắng 14. Use the following tables and data,All of the fields are Integers.The table names are Q A B C D 1 2 3 4 1 3 5 7 2 3 4 5 2 4 6 8 5 6 7 8 How many records does the following SQL example return? SELECT * FROM Q WHERE A>=5 OR D>=7; a) 1 b) 2 c) 3 d) 4 15. How many records does the following SQL example return? SELECT sum(A) AS S FROM Q GROUP BY A; 16. The SQL below will return one value. What is it? 17. How many records does the following SQL example return? SELECT count(*) FROM Q GROUP BY A, B; a) 2 b) 3 c) 4 d) 6 e) None of the above 18. Use the following tables and data All of the fields are Integers.The table names are R and How many records does the following SQL example return? SELECT COUNT(*) FROM R, S WHERE R.A=S.D OR R.B=S.E; a) 1 b) 2 c) 3 d) 4 19. How many records does the following SQL example return? SELECT COUNT(*) FROM R, S WHERE R.A=S.D; a) 0 b) 1 c) 2 d) 4 . Q is: (not superkeys) (a).2 (b).3 (c) ,4 (d).5 Giáo Trình Cơ Sở Dữ Liệu Trang 97 Biên soạn : Phan Tấn Quốc- Trường Cao Đẳng Kỹ Thuật Cao Thắng 14. Use the following tables and data,All. A B C D 1 2 3 4 1 3 5 7 2 3 4 5 2 4 6 8 5 6 7 8 How many records does the following SQL example return? SELECT * FROM Q WHERE A>=5 OR D>=7; a) 1 b) 2 c) 3 d) 4 15. How many. the product operator, if table A has 2 rows and table B has 4 rows, the number of rows in the product of these two tables is: (a) 4. (b) 8. (c) 16. (d) 20. 12. Suppose relation R(A,B,C,D,E)