1. CSIS 115 Database Design and Applications for Business
Dr. Meg Fryling
“Dr. Meg”
Fall 2012
@SienaDrMeg
#csis115
© 2012 Meg Fryling

2. Agenda Chapter 3: The Relational Model and Normalization Quiz (TODAY)
Take online via Blackboard before 11:59pm
Must complete quiz once it is started
Homework 4
Due Wednesday, November 28th by START of class

3. Normalizing for Data Integrity
Data integrity problems happen when data are duplicated
Normalized tables eliminate data duplication
General goal of normalization is to construct tables so every table has a single topic or theme
One fact – one place!
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall

4. BCNF defined
Relational design principles for normalized relations in BCNF:
Every determinant in every table must be a candidate key
Any table that is not well formed should be broken into two or more well-formed tables.
KROENKE and AUER - DATABASE CONCEPTS (3rd Edition)
© 2008 Pearson Prentice Hall

5. Straight to BCNF Steps Identify every functional dependency
Identify every candidate key
Check the determinants of each FD. If any determinant is not a candidate key, the table is not well-formed. Perform the following:
Place all the columns of the FD in a NEW table.
Make the determinant of the FD the PK of the new table.
Leave a copy of the determinant in the old table as a FK.
Create a referential integrity constraint between old and new tables.
Repeat above step until every determinant of every table is a candidate key

6. Now you do it! Advisor Table
Functional Dependencies
Determinates
Normalize to BCNF

7. Convert to BCNF: SKU_DATA
Is it in BCNF? How can we tell?
What are the functional dependencies? (we already figured this out)
What are the candidate keys?
Are all determinates candidate keys?
KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

8. Convert to BCNF: SKU_DATA
SKU_DATA (SKU, SKU_Description, Department, Buyer)
SKU  (SKU_Description, Department, Buyer)
SKU_Description  (SKU, Department, Buyer)
Buyer  Department
Buyers only have one department
Department NOT  Buyer
Multiple buyers for the same department
SKU_DATA (SKU, SKU_Description, Buyer)
BUYER (Buyer, Department)
SKU  (SKU_Description, Department, Buyer)
SKU_Description  (SKU, Department, Buyer)
Buyer  Department
Buyers only have one department
Department NOT  Buyer
Multiple buyers for the same department

9. Convert to BCNF: New Relations
How would you make this design better???
KROENKE AND AUER - DATABASE PROCESSING, 11th Edition © 2010 Pearson Prentice Hall

10. Now you do it! Functional Dependencies Determinates
Normalize Course table to BCNF

11. Normalization Activity
Blackboard In-Class Activities > Normalization