The classic example of database paradigm, what are you doing?

We can point out the shortcomings! ! !

1. In a normalized relationship model, all attributes must be ().
   

2. Suppose the relational model R belongs to the first normal form. If part of the functional dependence is eliminated in R, then R belongs to at least ().
   Resolution :The second paradigm is complete dependence, eliminating partial dependence.
   If part of the functional dependency is eliminated in R, it is at least in the second normal form.

3. Suppose the relational model R {A, B, C, D, E}, on which the functional dependence set F = {AB → C, B → D}, how many normal forms can R reach? ().
   
   Analysis: From the title: AB is the primary key

4. In the relationship model R (A, B, C, D), if there is a functional dependency set F = {B → C, C → D, D → A}, how many paradigms can R reach? ()
   

5. Set up the relationship mode R (A, B, C, D, E, F), the function dependency set F = {(A, B) → E, (A, C) → F, (A, D) → B, B → C, C → D}, which of the following are candidate codes for R ().
   

6. There is a relationship mode W (C, P, S, G, T, R), where the meaning of each attribute is: C is the course number, P is the teacher, S is the student, G is the grade, T is the time, R is the classroom , According to the definition, there are the following functional dependency set: F = {C → P, (S, C) → G, (T, R) → C, (T, P) → R, (T, S) → R} The following questions:
   (1) A code of the relationship pattern W is ().
   (2) The degree of normalization of W is up to ().
   
   Answer: B
   (3) If the relationship model W is decomposed into three relationship models W1 (C, P), W2 (S, C, G), W3 (S, T, R, C), then W3 has the highest degree of normalization Reach ().
   
   Answer: C
   7. There is a relationship R as shown below (1). The normalization degree of the existing relationship R is up to ().
   
   (2). In order to achieve 3NF, the relationship R can be decomposed into R1 and R2, which are described as follows: