1. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-1 David M. Kroenke’s Chapter Four: Database Design Using Normalization Database Processing: Fundamentals, Design, and Implementation

2. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-2 Chapter Premise Received one or more tables of existing data Need to store data in new database Problem: Store data as received, or transform?

3. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-3 How Many Tables? One, two, more?

4. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-4 Assessing Table Structure

5. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-5 Counting Rows in a Table To count the number of rows in a table use the SQL built-in function COUNT(*): SELECTCOUNT(*) AS NumRows FROMSKU_DATA;

6. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-6 Examining the Columns To determine the number and type of columns in a table, use an SQL SELECT statement To limit the number of rows retreived, use the SQL TOP {NumberOfRows} keyword: SELECTTOP (10) * FROM SKU_DATA;

7. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-7 Checking Validity of Assumed Referential Integrity Constraints Given two tables with an assumed foreign key constraint: SKU_DATA (SKU, SKU_Description, Department, Buyer) BUYER(BuyerName, Department) Where SKU_DATA.Buyer must exist in BUYER.BuyerName

8. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-8 Checking Validity of Assumed Referential Integrity Constraints To find any foreign key values that violate the foreign key constraint: SELECTBuyer FROM SKU_DATA WHEREBuyer NOT IT (SELECTBuyer FROM SKU_DATA, BUYER WHERESKU_DATA.BUYER = BUYER.BuyerName;

9. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-9 Type of Database Updateable Read-only

10. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-10 Updateable Database Normally, put tables in BCNF Always, remove MVD

11. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-11 Read-Only Database Likely not to use BCNF tables Remove MVD

12. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-12 Designing Updateable Databases

13. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-13 Normalization: Advantages and Disadvantages

14. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-14 Choosing Not to Use BCNF BCNF controls anomalies from functional dependencies BCNF is not, always, desirable Classic ZIP code example

15. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-15 Multivaled Dependencies MVDs cause very problematic anomalies Always place MVDs into a separate tables for operational databases.

16. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-16 Designing Read-Only Databases

17. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-17 Read-Only Database non-operational database data extracted from operational databases

18. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-18 Read-Only Databases For applications –querying –reporting –data mining NEVER updated operationally (new data imported)

19. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-19 Read-Only Databases Data Warehouse Data Mart Decision Support System

20. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-20 Read-Only Databases Normalization seldom an advantage Denormalization –Join data from normalized tables To create a new table –Store New non-normalized tables Not original normalized tables

21. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-21 Read-Only Databases Often, many copies of the same data Each customized for a specific application

22. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-22 Customized Tables PRODUCT_PURCHASING (SKU, SKU_Description, VendorNumber, VendorName, VendorContact_1, VendorContact_2, VendorStreet, VendorCity, VendorState, VendorZip) PRODUCT_USAGE (SKU, SKU_Description, QuantitySoldPastYear, QuantitySoldPastQuarter, QuantitySoldPastMonth) PRODUCT_WEB (SKU, DetailPicture, ThumbnailPicture, MarketingShortDescription, MarketingLongDescription, PartColor) PRODUCT_INVENTORY (SKU, PartNumber, SKU_Description, UnitsCode, BinNumber, ProductionKeyCode)

23. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-23 Creating Databases from Existing Tables Generally, accomplished by automated means –Import –SQL Beyond the scope of this class

24. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-24 Common Design Problems

25. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-25 The Multivalue, Multicolumn Problem WORKER (WorkerID, Name, Skill-Type, BuildID1, BuildID2, BuildID3) Problems?

26. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-26 The Multivalue, Multicolumn Problem WORKER (WorkerID, Name, Skill-Type, BuildID1, BuildID2, BuildID3) Another form of a MVD A Different Solution: –use separate table to store multiple values –WORKER ( WorkerID, Name, Skill-Type) –ASSIGNMENT (WorkerID, BuildingID

27. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-27 Inconsistent Values: Different forms of the same data value Different codings: CommonName = ‘Blueberry' CommonName = ‘Huckleberry' CommonName = ‘Wild Blueberry‘ Different spellings: ‘Blueberry’ ‘Blueberries’ ‘BLUBERRY’

28. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-28 Inconsistent Values Particularly problematic are –primary key values,or –foreign key values To detect: –Some semi-automatic methods –Beyond the scope of this class

29. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-29 Null Values Missing value Not a blank Not a zero Never been provided!

30. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-30 Null Values Ambiguous: –May indicate n/a –May indicate applicable but unknown –May indicate value applicable and known, but never entered When is your DB fault intolerant of null values?

31. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-31 The General-Purpose Remarks Column Black Hole –Remarks –Comments –Notes Such a column may: –Be used inconsistently –Hold multiple data items

32. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-32 The General-Purpose Remarks Column Example – Figure 4-10, p. 118

33. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-33 The General-Purpose Remarks Column Decompose column into separate columns Manual task

34. DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition © 2006 Pearson Prentice Hall, modified by Dr. Lyn Mathis 4-34 David M. Kroenke’s Database Processing Fundamentals, Design, and Implementation (10 th Edition) End of Presentation: Chapter Four