1. Chapter 2: The Database Development Process Modern Database Management 9 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Heikki Topi 1 © 2009 Pearson Education, Inc. Publishing as Prentice Hall

2. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Enterprise Data Model First step in database development First step in database development Specifies scope and general content Specifies scope and general content Overall picture of organizational data at high level of abstraction Overall picture of organizational data at high level of abstraction Entity-relationship diagram Entity-relationship diagram Descriptions of entity types Descriptions of entity types Relationships between entities Relationships between entities Business rules Business rules 2

3. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 3 Segment from enterprise data model Enterprise data model describes the high- level entities in an organization and the relationship between these entities

4. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Two Approaches to Database and IS Development SDLC SDLC System Development Life Cycle System Development Life Cycle Detailed, well-planned development process Detailed, well-planned development process Time-consuming, but comprehensive Time-consuming, but comprehensive Long development cycle Long development cycle Prototyping Prototyping Rapid application development (RAD) Rapid application development (RAD) Cursory attempt at conceptual data modeling Cursory attempt at conceptual data modeling Define database during development of initial prototype Define database during development of initial prototype Repeat implementation and maintenance activities with new prototype versions Repeat implementation and maintenance activities with new prototype versions 4

5. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle 5 Planning Analysis Physical Design Implementation Maintenance Logical Design

6. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle (cont.) 6 Planning Analysis Physical Design Implementation Maintenance Logical Design Planning – Purpose – preliminary understanding – Deliverable – request for study – Database activity – enterprise modeling and early conceptual data modeling

7. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle (cont.) 7 Planning Analysis Physical Design Implementation Maintenance Logical Design Analysis Purpose–thorough requirements analysis and structuring Deliverable–functional system specifications Database activity–thorough and integrated conceptual data modeling

8. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle (cont.) 8 Planning Analysis Physical Design Implementation Maintenance Logical Design Purpose–information requirements elicitation and structure Deliverable–detailed design specifications Database activity– logical database design (transactions, forms, displays, views, data integrity and security)

9. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle (cont.) 9 Planning Analysis Physical Design Implementation Maintenance Logical Design Physical Design Purpose–develop technology and organizational specifications Deliverable–program/data structures, technology purchases, organization redesigns Database activity– physical database design (define database to DBMS, physical data organization, database processing programs)

10. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle (cont.) 10 Planning Analysis Physical Design Implementation Maintenance Logical Design Implementation Purpose–programming, testing, training, installation, documenting Deliverable–operational programs, documentation, training materials Database activity– database implementation, including coded programs, documentation, installation and conversion

11. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Systems Development Life Cycle 11 Planning Analysis Physical Design Implementation Maintenance Logical Design Maintenance Purpose–monitor, repair, enhance Deliverable–periodic audits Database activity– database maintenance, performance analysis and tuning, error corrections

12. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 12 Prototyping Database Methodology

13. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 13 Prototyping Database Methodology (cont.)

14. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 14 Prototyping Database Methodology

15. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 15 Prototyping Database Methodology

16. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 16 Prototyping Database Methodology

17. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Packaged Data Models Model components that can be purchased, customized, and assembled into full-scale data models Model components that can be purchased, customized, and assembled into full-scale data models Advantages Advantages Reduced development time Reduced development time Higher model quality and reliability Higher model quality and reliability Two types: Two types: Universal data models Universal data models Industry-specific data models Industry-specific data models 17

18. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Managing Projects reach an objective that has a beginning and an end Project–a planned undertaking of related activities to reach an objective that has a beginning and an end Involves use of review points for: Involves use of review points for: Validation of satisfactory progress Validation of satisfactory progress Step back from detail to overall view Step back from detail to overall view Renew commitment of stakeholders Renew commitment of stakeholders Incremental commitment–review of systems development project after each development phase with re justification after each phase Incremental commitment–review of systems development project after each development phase with re justification after each phase 18

19. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall Managing Projects: People Involved Business analysts Business analysts Systems analysts Systems analysts Database analysts and data modelers Database analysts and data modelers Users Users Programmers Programmers Database architects Database architects Data administrators Data administrators Project managers Project managers Other technical experts Other technical experts 19

20. Database Schema : describes how data is stored. The way perceived by the DBMS & OS. Internal level : describes how data is stored. The way perceived by the DBMS & OS. Conceptual level : describes what data stored in DB, and the relationships among the data. The way perceived by the DBA & programmers. Conceptual level : describes what data stored in DB, and the relationships among the data. The way perceived by the DBA & programmers. External level : describes the part of the DB that user is interested in. The way perceived by the end users. External level : describes the part of the DB that user is interested in. The way perceived by the end users. 20 Database Systems: A Practical Approach to Design, Implementation and Management, by T. Connolly and C. Begg.

21. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 21 Different people have different views of the database…these are the external schema The internal schema is the underlying design and implementation Three-schema architecture

22. Chapter 2 © 2009 Pearson Education, Inc. Publishing as Prentice Hall 22 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall