Hello How should I resolve this Exercise 521 Here are two re
Hello. How should I resolve this Exercise 5.2.1: Here are two relations:
R(A,B): {(0,1), (2,3), (0,1), (2,4), (3,4)}
S(B,C): {(0,1), (2,4), (2,5), (3,4), (0,2), (3,4)}
Compute the following: Part: C - H (Please check the pdf file attached, I cannot write the specific question because I dont have the option to write geek letters on my keyboard) Chapter 5, section 5.2 Exercise 5.2.1 part c - h. Thank you
Textbook: Database Systems: The Complete Book 2nd edition, by Hector Garcia-Molina, Jeff Ullman and Jennifer Widom, Prentice Hall, 2008. ISBN: 978-0131873254
http://people.inf.elte.hu/sila/DB1Lect/Ullman_The_Complete_Book.pdf
Solution
Question c: Sort relation R on the basis of B and then A
Ans: R(A,B): {(0,1),(0,1),(2,3),(2,4),(3,4)}
Question d: Sort relation S on the basis of B and then A
Ans: S(B,C): {(0,1),(0,2),(2,4),(2,5),(3,4),(3,4)}
Question e: Get unique values of relation R
Ans: R(A,B):{(0,1),(2,3),(2,4),(3,4)}
Question f: Get unique values of relation R
Ans: S(B,C): {(0,1),(2,4),(2,5),(3,4),(0,2)}
