1. CS 3630 Database Design and Implementation

2. 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 PK.
Slides 2-5 copied from Note14 and should be removed after done
Could keep all slides here!
Enough time to answer all questions!

3. Lease (RNo, RName, PNo, PAddress, Start, Finish, Rent, ONo, OName)
Primary Key: PNo, Start
FDs:
PNo, Start ---> RNo, RName, PAddress, Finish, Rent, ONo, OName
PNo ---> PAddress, ONo, Oname (Partial on PK!)
Lease1 (PNo, PAddress, ONo, OName)
Primary Key: Pno
Alternate Key: None
Foreign Key: None
PNo ---> PAddress, ONo, OName
PAddress  Pno
ONo ---> OName
Lease2 (RNo, RName, PNo, Start, Finish, Rent)
Foreign Key: PNo References Lease1
PNo, Start ---> RNo, RName, Finish, Rent
RNo ---> RName

4. Better Name for the Two Tables
Lease (RNo, RName, PNo, PAddress, Start, Finish, Rent, ONo, OName)
Primary Key: PNo, Start
Better Name for the Two Tables
Lease1 (PNo, PAddress, ONo, OName)
Primary Key: Pno
Property
Lease2 (RNo, RName, PNo, Start, Finish, Rent)
Lease

5. Property (PNo, PAddress, ONo, OName)
Primary Key: PNo
FDs:
PNo ---> PAddress, ONo, OName
PAddress  PNo
ONo ---> OName
Table Instance
PNo PAddress ONo OName
P main O Tina
P main O Tony
P first O Tony
P first O Tony
In 2NF?
But still some Redundancy
Reason?

6. Third Normal Form (3NF) No Transitive FDs on PK.
Relation R in 2NF, and
No non-Primary-Key attribute is transitively functionally dependent on the primary key
Then R is in 3NF.
No Transitive FDs on PK.

7. Transitive FDs If A  B and B  C Then A  C is always TRUE
(provided A is not functionally dependent on either B or C)
(NO cycle!)

8. Transitive FDs A B C
If A  B and B  C
Then A  C

9. Transitive FDs A B C If A  B and B  C Then A C
Provided not B  A (A and B are equivalent)
nor C  A (A, B and C are equivalent)
No Cycle!

10. Property (PNo, PAddress, ONo, OName) FDs:
Primary Key: PNo
FDs:
PNo ---> PAddress, ONo, OName
PAddress ---> PNo
ONo ---> OName
Table Instance
PNo PAddress ONo OName
P main O Tina
P main O Tony
P first O Tony
P first O Tony
In 2NF, but still some redundancy
Not in 3NF!
PNo ---> ONo, Oname
Ono --> Oname
(Oname is transitively functionally dependent on Pno)

11. Decompose Property into 3NF
Property (PNo, PAddress, ONo, OName)
PNo ---> PAddress, ONo, OName
PAddress ---> PNo
ONo ---> OName
Property1 (ONo, OName)
Primary Key: Ono
Alternate Keys: None
Foreign Keys: ?
FDs:
ONo ---> Oname
Property2 (PNo, PAddress, ONo)
Primary Key: PNo
Alternate Keys: PAddress
Foreign Keys: ?
FDs:
PNo ---> PAddress, ONo
PAddress  Pno

12. Decompose Property into 3NF
Property (PNo, PAddress, ONo, OName)
PNo ---> PAddress, ONo, OName
PAddress ---> PNo
ONo ---> OName
Property1 (ONo, OName)
Primary Key: Ono
Alternate Keys: None
Foreign Keys: None
FDs:
ONo ---> Oname
Better table name?
Owner
Property2 (PNo, PAddress, ONo)
Primary Key: PNo
Alternate Keys: PAddress
Foreign Keys: Ono references Property1
FDs:
PNo ---> PAddress, ONo
PAddress  Pno
Better table name?
Property

13. Decompose Property into 3NF
Property (PNo, PAddress, ONo, OName)
PNo ---> PAddress, ONo, OName
PAddress ---> PNo
ONo ---> OName
Owner (ONo, OName)
Primary Key: Ono
Alternate Keys: None
Foreign Keys: None
FDs:
ONo ---> Oname
Property (PNo, PAddress, ONo)
Primary Key: PNo
Alternate Keys: PAddress
Foreign Keys: Ono references Owner
FDs:
PNo ---> PAddress, ONo
PAddress  Pno

14. Table Instances Property PNo PAddress ONo OName
P main O Tina
P main O Tony
P first O Tony
P first O Tony
Property
PNo PAddress Ono
P main O100
P main O109
P first O109
P first O109
Owner
ONo OName
O Tina
O Tony

15. Final Tables
Lease Property Owner

16. Relation R
R (A, B, C, D, E, F)
Primary Key: A, B
Alternate Keys: None
Functional Dependencies:
A, B ---> C, D, E, F
C ---> D
E ---> F
Is it in 2NF?
Is it in 3NF?
How many tables we will have to decompose it into 3NF?

17. Exercise 3NF Table Instance A B C D E F 1 x 10 100 se 400
y cis
x cis
y ct
A, B ---> C, D, E, F
C > D
E > F

18. Decompose R into 3NF R (A, B, C, D, E, F) PK: A, B AK: None FK: None
FDs:
A, B ---> C, D, E, F
C ---> D
E ---> F
R3 (A, B, C, E)
Primary Key: A, B
Alternate Keys: None
Foreign Key: C References R1
E References R2
Functional Dependencies:
A, B ---> C, E
R1 (C, D)
Primary Key: C
Alternate Keys: None
Foreign Key: None
Functional Dependencies:
C ---> D
R2 (E, F)
Primary Key: E
Alternate Keys: None
Foreign Key: None
Functional Dependencies:
E ---> F

19. Table Instances R (A, B, C, D, E, F) A B C D E F 1 x 10 100 se 400
y cis
x cis
y ct
R (A, B, C, E)
A B C E
x se
y cis
x cis
y ct
R1 (C, D)
C D
R2 (E, F)
E F se
cis ct

20. Assignment 5-2 Due Thursday, March 9 Quiz 2 Wednesday, March 8
Schedule
Assignment 5-2 Due Thursday, March 9 Quiz 2 Wednesday, March 8