1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
sattari [20]
3 years ago
15

Consider the universal relation r = {a, b, c, d, e, f, g, h, i, j} and the set of functional dependencies f = { {a, b } → {c}, {

a}→{d, e}, {b}→{f}, {f}→{g, h}, {d}→{i, j} }. what is the key for r? decompose r into 2nf and then 3nf relations

Mathematics
1 answer:
nekit [7.7K]3 years ago
8 0

Answer:

relation of FDs are {a, b, d, h}. From these all but {h}

seem plausibly part of keys. Calculating the closures of likely candidates gives:

{a, b} + = {a b, c, i}

{b, d} + = {b, d, e, f}

{a, d} + = {a, d, g, h, i, j}

{a, b, d} + = {a, b, c, d, e, f, g, h, i, j}  

decompose r into 2nf and then 3nf relations shown in attachment.                    

Step- by-Step Explanation

Explanation is given in the attachment.

You might be interested in
I need help with this question
Viktor [21]
Y = 4x + 3  ---------(1)
y = -x - 2    ---------(2)

Subtract (2) from (1), you get
0 = 5x + 5
⇒ 5x + 5 = 0
⇒ 5x = -5
⇒ x = -5/5 = -1
y = -(-1) - 2 = -1

Answer is (-1,-1)
5 0
3 years ago
How do i solve this problem
mamaluj [8]
As they are similar corresponding sides are in the same ratio, so

18/15 = x / 4

x = 4*18 / 15
x = 4.8 answer
7 0
2 years ago
Can someone answer this problem fast for me please
agasfer [191]

1 \times  {3}^{100}
8 0
3 years ago
Please help asap!!!!!!!!!!!
mars1129 [50]
X = 59, y = 44

2x + 18 + x - 15 = 180
3x + 3 = 180
3x = 177
x = 59

x - 15 = y
59 - 15 = y
44 = y
6 0
2 years ago
Read 2 more answers
What is a correct expansion of (3x + 2)(3x^2 + 4)
worty [1.4K]
It would be 9x^3+6x^2+12x+8

3 0
3 years ago
Other questions:
  • I feel like it is add x but i am bad at math
    7·2 answers
  • let x be the number of loads carriers and y the number of loads by air carrier.which system of inequalities represent this solut
    5·1 answer
  • From a deck of 52 cards, one card is drawn at random. Match the following subsets with their correct probabilities.
    7·2 answers
  • Triangle ABC is a right triangle. Which equations can be used to find the value of x? Check all that apply.
    6·2 answers
  • Please answer this question. FOLLOW ALL OF THE INSTRUCTIONS to get the right anser please. THANK YOU!
    8·1 answer
  • Solve for x.<br>7x+ 3<br>3x + 35<br><br>x = [?]<br>​
    14·1 answer
  • Factories A and B produce computers. Factory A produces 3 times as many computers as factory B. The probability that an item pro
    6·1 answer
  • Find the value of x in the figure below.<br> Assume that the lines are parallel.
    5·1 answer
  • Mrs. Daniel packs reams of paper into boxes. The box has a mass of 18
    12·1 answer
  • Find x (Round to the nearest tenth). PLS HURRY
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!