Post your solutions to the Oct 2 In-Class Exercise to this thread. Best, Chris

-- Oct 2 In-Class Exercise Thread

{A}+ = {A} {B}+ = {B} {C}+ = {C} {A, B}+ = {A, B} {A, C}+ = {A, C} {B, C}+ = {B, C} {A, B, C}+ = {A, B, C}

-- Oct 2 In-Class Exercise Thread

{| |- | Professor || Class || Title |- | Pollett || CS157A || Intro to databases |- | Pollett || CS157B || Databases management systems |} <br> <br> {| |- | Recipe || Ingredient || amount |- | sauteed scalops || garlic || 1 |- | sauteed scalops || scalops || 10 |- | Mushrooms a la creme || creme || 50ml |- | Mushrooms a la creme || mushrooms || 200g |}

-- Oct 2 In-Class Exercise Thread

R(name, makeModel, year) (Person1, Toyota Prius, 2012) (Person1, Nissan Leaf, 2012) (Person2, Toyota Prius, 2010) (Person2, Nissan Leaf, 2010)

-- Oct 2 In-Class Exercise Thread

 Joseph|Nguyen|CS157a 
 Joseph|Nguyen|CS156
 Joseph|Tran|CS157a
 Joseph|Tran|CS156

 If we know Joseph we don't know the second column (A -\-> B)

Joseph|Nguyen|CS157a Joseph|Nguyen|CS156 Joseph|Tran|CS157a Joseph|Tran|CS156 If we know Joseph we don't know the second column (A -\-> B)

-- Oct 2 In-Class Exercise Thread

Product(Brand, Product Name, Color) (Adidas, T-shirt, Blue) (Adidas, Shorts, Blue) (Adidas, T-shirt, black) (Adidas, Shorts, black)

-- Oct 2 In-Class Exercise Thread

for R(A,B,C) => R(Class Code, Class Title and Year, Class Time) {| |- ! Class Code !! Class Title and year !! Class Time |- | 1432 || Computer Networks (2018) || M/W 9-10am |- | 1432 || Operating Systems (2019) || M/W 9-10am |- | 1121 || Intro to Database (2018) || F 6-9pm |- | 1121 || Data Structures (2019) || F 6-9pm |}

-- Oct 2 In-Class Exercise Thread

  R(A, B, C)
  (Student1, Class1, Room1)
  (Student1, Class2, Room2)
  (Student1, Class1, Room3)
  (Student1, Class2, Room4)

R(A, B, C) (Student1, Class1, Room1) (Student1, Class2, Room2) (Student1, Class1, Room3) (Student1, Class2, Room4) A multivalue determines B. Yet, A does not fix B.

-- Oct 2 In-Class Exercise Thread

This is an example of a multi-valued dependency (MVD) because the name of company (attribute A) fixes a list of possible field (attribute B), including food and cosmestics A | B |C Ali | Food | 4.0 Ali | Cosmetics | 2.3 Ali | Food | 3.0 Ali | Cosmetics | 4.3

-- Oct 2 In-Class Exercise Thread

 (tina, condo, 1928)
 (paul, townhouse, 2849)
 (tina, townhouse, 1928)
 (paul, condo, 2849)

R(colA, colB, colC) R(person, house type, purchase date) (tina, condo, 1928) (paul, townhouse, 2849) (tina, townhouse, 1928) (paul, condo, 2849)