1. CS 3630 Database Design and Implementation

2. Unnormalized Form (UNF)
student courses
Mike Rowe CS3630
CS3340
CS3230
Multi-Value attribute
Common in reports
2NF and 3NF could be in one note.

3. First Normal Form (1NF) No multi-value attributes
Done when mapping E-R model to relational schema
DBDL

4. Second Normal Form (2NF)
A relation R is in 1NF, and
every non-primary-key attribute is fully functionally dependent on the primary key
Then R is in 2NF
No Partial FDs on the PK.

5. Example Relation R (A, B, C, D, E, F) PK: A, B AK: None FK: None
Functional Dependencies:
A, B  All
A  C
B  E, F

6. Table Instance A B C D E F 1 x 10 100 cs se 1 y 10 200 cs ee
Functional Dependencies:
A, B  All
A  C
B  E, F

7. In 2NF? Relation R (A, B, C, D, E, F) PK: A, B AK: None FK: None
Functional Dependencies:
A, B  All
A  C
B  E, F

8. How Many Tables Relation R (A, B, C, D, E, F) PK: A, B AK: None
FK: None
Functional Dependencies:
A, B  All
A  C
B  E, F

9. Decomposing Tables into 2NF
Which attributes go to new tables?
Which attributes stay in the original table?
What is the PK?
Which tables have the FK?
How many records each table should have?

10. Decompose table R into 2NF
R (A, B, C, D, E, F)
Functional Dependencies:
A, B  All
A  C
B  E, F
R1 (A, C)
PK: A
AK: None
FK: ?
FDs:
A  C
R2 (B, E, F)
PK: B
B  E, F
R (A, B, D)
PK: A, B
A, B  D

11. Decompose table R into 2NF
R (A, B, C, D, E, F)
Functional Dependencies:
A, B  All
A  C
B  E, F
R1 (A, C)
PK: A
AK: None
FK: None
FDs:
A  C
R2 (B, E, F)
PK: B
B  E, F
R (A, B, D)
PK: A, B
FK: A references R1
B references R2
A, B  D

12. Table Instance R A B C D E F 1 x 10 100 cs se 1 y 10 200 cs ee
A B D x y x y R1
A C R2
B E F
x cs se
y cs ee

13. Schedule
Assignment 6-1 Due Thursday, March 1 At 5 PM Quiz 2 Wednesday, March 7 Covers A4 and A51, A61

14. Assignment 5-2
Due Monday, March 5 At 5 PM