Let R(A, B, C, D, E) be a relation with the set of FD's: F = {D → C, C → D, D →A, C –→ A, E → C, E –→ A, E → B, B → C}. Which of the following statements is NOT correct? Select one: O G= {D → C, C → D, D → A, E → B, B → C} is a canonical cover (minimal basis) of F. O H = {D → C, C → D, C → A, E → B, B → C} is a canonical cover of F.

Let R(A, B, C, D, E) be a relation with the set of FD's: F = {D → C, C → D, D →A, C –→ A, E → C, E –→ A, E → B, B → C}. Which of the following statements is NOT correct? Select one: O G= {D → C, C → D, D → A, E → B, B → C} is a canonical cover (minimal basis) of F. O H = {D → C, C → D, C → A, E → B, B → C} is a canonical cover of F.

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 R be the relation R = {(a, b) | a < b} on the set of integers. Find a) R-1. b) R.
2. Find the following elements in Z₁,: a. 13 x₁, 17 b. 13 +19 17 c. -12 (the additive inverse of 12): d. 12¹ (the multiplicative inverse of 12): 3. Which of the following best characterizes the statements A) The relation "divides" on the set of prime numbers has the reflexive property B) The relation "divides" on the set of prime numbers has the symmetric property a. Only A is TRUE b. Only B is TRUE c. Both A and B are TRUE d. Both A and B are FALSE
15. Code to Recurrence Relation What is the recurrence relation of the runtime of the following algorithm: T(n) represents the time it takes to complete func called with the parameter n value n. def func(n): if n == 0: return print(n) func(n//2) func(n//3) Pick ONE option T(n) = T(n-1) + T(n-2) + C; T(1) = C T(n) = T(n-2) + T(n-3) + C; T(1) = C T(n) = T(n/2) + T(n/3) + C; T(1) = C T(n) = T(n-5) + C; T(1) = C Clear Selection 81
Implement the following Racket functions: Transitive? Input: a list of pairs, L. Interpreting L as a binary relation, Transitive? returns #t if L is a transitive relation and #f otherwise. Examples: (display "Transitive? \n") (Transitive? '((a b) (b c) (a c))) ---> #t (Transitive? '((a a) (b b) (c c))) ---> #t (Transitive? '((a b) (b a))) ---> #f (Transitive? '((a b) (b a) (a a))) ---> #f (Transitive? '((a b) (b a) (a a) (b b))) ---> #t (Transitive? '())---> #t
Q2: When the following FDs are defined in R(A, B, C, D), А — D, CD — В, А —— С (1) Identify the candidate key(s) in R. (2) Identify the best normal form that R satisfies (1NF, 2NF, 3NF, or BCNF) (3) If R is not in BCNF, decompose it into a set of BCNF relations that preserve the dependencies.
PLEASE TYPE ONLY**** ANSWER ALL THREE QUESTIONS Exercise 8.1.4: Arrow diagrams for relations on small finite sets. Draw the arrow diagram for each relation. (b) The domain of relation P is {2, 4, 8, 16, 32, 64}. For x, y in the domain, xPy if there is a positive integer n such that xn = y. (c) The domain of relation D is {2, 3, 12, 16, 27, 48}. For x, y in the domain, xDy if y is an integer multiple of x. (d) The domain for the relation A is the set {2, 5, 7, 8, 11}. For x, y in the domain, xAy if |x-y| is less than 2
Consider the following sets: A={2,4,5} B = {4,9,10,12} C = {1,3,8,9,10,12,14} I) Find all the elements of the set C\ (AUB): II) Find | C\ (AUB) | III)Let R is a relation on the set A = { 2, 4, 5}, with: R:A×A, write the resulted set R ?
Function cai (Io) should return companies whose shares are held by every investor i E I, It is defined recursively: • Base case:. cai(null) = null • Constructor case: cai ({i1, i2...in }) = {c| cE C and. ( i1, c) E IC ) n cai ({i1, i2...in})
Let S be a set with |S| = 5. How many relations are there on S? A. 5! В. 55 C. 520 D. 525 Е. 225 A В E C.
Let A = {a, b, c}, B = {x, y}, and C = {0, 1}. Identify B × B × B.
1. Consider strings that contain only the capital letters A, B and C. A) Find a recurrence relation for the number of such strings of length n that contain two consecutive C letters. What are the initial conditions? B) How many such strings of length six contain two consecutive C letters? C) Answer the question in point b using the Inclusion-Exclusion Principle (set A contains all strings of length six where CC occupy the first two positions, set B contains all strings of length six where CC occupy the second and third position, etc.).
Are the functions one to one or onto only? I. f : N → Z : x ↔ x II. f : N → N : x ↔ x III. f : Z → N ∪ {0} : x ↔ |x|