1. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 1 Data Storage Design (or ‘what you do after ERDs’)

2. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 2 Key Definitions The data storage function manages how data is stored and handled by programs that run the system? Goals of the data storage design function are ending up with efficient data retrieval (good response time) and having users able to retrieve the information they need.

3. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 3 Data Storage Formats

4. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 4 Types of Data Storage Format Files are electronic lists of data optimised to perform a particular transaction A database is a collection of groupings of information the relate to each other in some way. A Database Management System (DBMS) is software that creates and manipulates these databases.

5. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 5 Customer Order Database

6. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 6 File Attributes Typically organised sequentially Pointers Linked Lists

7. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 7 File Types Master files Transaction files Look-up files Audit files History files

8. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 8 Hierarchical Database Example

9. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 9 Network Database Example

10. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 10 Relational Database Concepts Keys Referential integrity SQL Joining tables

11. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 11 Object Database Example

12. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 12 Multi-dimensional Database Example

13. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 13 Optimizing Data Storage

14. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 14 Dimensions of Data Storage Optimization Storage efficiency (minimizing storage space) Speed of access (minimizing time to retrieve desired information)

15. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 15 Storage Efficiency Minimize null values Reduce update anomalies

16. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 16 Optimizing Data Storage

17. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 17 The Steps of Normalization

18. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 18 Zero Normal Form (0NF)

19. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 19 The Steps of Normalization

20. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 20 First Normal Form (1NF) Product Number

21. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 21 The Steps of Normalization

22. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 22 Second Normal Form (2NF)

23. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 23 The Steps of Normalization

24. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 24 Third Normal Form (3NF)

25. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 25 Optimizing Access Speed Denormalization Clustering Intra-file Inter-file Indexing

26. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 26

27. PowerPoint Presentation for Dennis & Haley Wixom, Systems Analysis and Design Copyright 2000 © John Wiley & Sons, Inc. All rights reserved. Slide 27 Summary Files are electronic lists of data generally of five types: master, look-up, transaction, audit, and history. A database is a collection of groupings of information and a DBMS is software that creates and manipulates these. There are a number of methods for optimizing data access speed and data storage efficiency, though the designers may have to make tradeoffs between these goals.