Assume we have two relations R(a,b) and S(b,c). All three attributes (a, b, and c) are integer attributes. Assume that Relation R contains the following tuples: (1,2), (2,3), (4,7) and (3,4). Assume that Relation S contains the following tuples (2,2), (2,3), (4,6) and (7,5). How many tuples are in the result of Natural Join between R and S?

Assume we have two relations R(a,b) and S(b,c). All three attributes (a, b, and c) are integer attributes. Assume that Relation R contains the following tuples: (1,2), (2,3), (4,7) and (3,4). Assume that Relation S contains the following tuples (2,2), (2,3), (4,6) and (7,5). How many tuples are in the result of Natural Join between R and S?

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

Let A1, A2, and A3 be attributes in a relation R. If both of these functional dependencies hold: A1 → A2 and A2 → A3, then A1 → A3 holds, because of the_? rule.
p.609, icon at Example 2 # 2. Let A be the set of all points in the plane with the origin removed. That is, Define a relation on A by the rule: A = {(x, y)|x, y = R} - {(0,0)}. (a, b)R(c, d) ↔ (a, b) and (c, d) lie on the same line through the origin. (a) Prove that R is an equivalence relation. (b) Describe the equivalence classes arising from the equivalence relation R in part (a). (c) If A is replaced by the entire plane, is R an equivalence relation?
Please only answer Excercise 3.2.2 Thank you Attcated an image.
1) Consider the following relation instance of R1(A, B, C) contains the tuples {(a1,b1.c1). (a2,b1,c1), (a3,b3,c3), (a4,b3,c3), (a5,b5.c5). (a6,b6,c6)} and S1(B, C, D, E) contains the tuples ((b1.c1,d1,e1), (b1.c1.d2.e2),.(b1.c1,d3,e3), (b2.c2,d2.e2), (b3,c3,d4,e4).(b6.c7.d8,e9)) The following SQL query will result in how many tuples? Select From R1 r LEFT OUTER JOIN S1 s (ON r.B= s.B AND r.C=s.C): (The answer will simply be an integer, like 25). Answer: 2) Consider a relation schema R = (A, B, C, D, E, F, G} with the following set of functional dependencies: F = (BG A, CGA, A BC, BC A, BD E, EF, CF B) The decomposition of R into R1 = (A, B, C, G), R2 = {B, D, E), R3 = (B, C, F) and R4 = (E, F) is O In BCNF but Not in 3NF. In 3NF but Not in BCNF. In 3NF and in BCNF. Not in 3NF and Not in BCNF 3)
Given the following relation: R(A, B, C, D, E, F, G) The functional dependencies that apply onto R are: AB> G B>E,F G>A A> CD 1. What normal form is the relation in? Why? 2. How would you successively normalize it completely? State the reason behind each decomposition step by step.
39 of 40 Let R = (A, B, C, D) be a relation schema with the FD's: A → B and B → A. R has how many superkeys? (Write your answer as an integer). write your answer here
For each of the following relations, determine whether the relation is: • Transitive. • A partial order. • A strict order. • An equivalence relation. Reflexive. Anti-reflexive. Symmetric. • Anti-symmetric. Justify all your answers. a. Ris a relation on the set of all people such that (a, b) e R if and only if a and b have a common grandparent. b. Ris a relation on Z such that (x, y) E R if and only if |x – y| < 2. c. Ris a relation on Z* such that (x, y) E R if and only if x is divisible by y. Hint: An integer x is divisible by an integer y with y # 0 if and only if there exists an integer k such that x = yk. d. Ris a relation on Z* such that (x, y) E R if and only if there is a positive integer n such that x" = y. e. Ris a relation on Z x Z such that ((a, b), (c, d)) E R if and only if a < c and b < d.
Assume that the advisor connection is one-to-one. What additional restrictions do you need on the relation advisor to implement the one-to-one cardinality constraint?
! Exercise 2.5.3: Suppose R and S are two relations. Let C be the referen- tial integrity constraint that says: whenever R has a tuple with some values Vr , V2, . . . , Un in particular attributes A1, A2,... , An, there must be a tuple of S that has the same values v1, v2,. .. , Vn in particular attributes B1, B2,... , Bn. Show how to express constraint C in relational algebra.