09-14-2009, Monday

1. Database Planning, Selecting DBMS, Case Tools and Fact Finding 09-14-2009, Monday CS8630 Dr. Mario Guimaraes • Class • Will • Start • Momentarily…

2. Database Planning • Database planning should include development of standards that govern: • how data will be collected, • how the format should be specified, • what necessary documentation will be needed, • how design and implementation should proceed. • Main Stages: Conceptual: defining the info. Without worrying about a model, • Logical: convert to tables without worrying about how it is stored, • Physical: how data is stored: int, varchar, float, etc.

3. Database System Definition Describes scope and boundaries of database application and the major user views. • User view defines what is required of a database application from perspective of: • a particular job role (such as Manager or Supervisor) or • enterprise application area (such as marketing, personnel, or stock control).

4. Integrating user views

5. DBMS Selection

6. DBMS Selection • Volume Estimates • Data Usage: entered, retrieved, deleted, updated • Response Time Requirements • Requirements for security, backup, recovery, retention, integrity Scalability Interaction with other systems Existing platforms ? Need to run in specific OS ?

7. Weighted Factor Scoring Model

8. Selecting a DBMS • http://www.dbmsmag.com/9607d11.html • http://www.craigsmullins.com/dbta_010.htm Enterprise, Departmental, Personal or Mobile ? Examples of DBMS Mobile: Oracle Lite, Sybase’s Ultralite Personal: MS-Access, Filemaker Pro Departmental: MySQL, POSTGRES, MS-SQL Server, Sybase, INFORMIX (possibly enterprise also) Enterprise: Oracle, DB2, MS-SQL Server,

9. CASE Tools • COMPUTER AIDED SOFTWARE ENGINEERING (CASE) Example: write in QBE, code comes out in SQL. • Support provided by CASE toolsinclude: • - data dictionary to store information about database application’s data; • - design tools to support data analysis; • - tools to permit development of corporate data model, and conceptual and logical data models; • - tools to enable prototyping of applications.

11. CASE • Provide following benefits: • standards; • integration; • support for standard methods; • consistency; • automation . • Quick prototypes, good for learning • Problems - Lack of Integration between high end and low end case. • Not always good for modifying • May lack flexibility - Silver bullet syndrome

12. CRUD Matrix How much will a CASE tool accelerate the construction of each of these Forms/Programs below ?

13. Prototypes • Building working model of a database application. • Purpose • to identify features of a system that work well, or are inadequate; • to suggest improvements or even new features; • to clarify the users’ requirements; • to evaluate feasibility of a particular system design.

14. Fact Finding • Formal process of using techniques such as interviews and questionnaires to collect facts about systems, requirements, and preferences.

15. Fact-Finding Techniques • Database developer normally uses several fact-finding techniques during a single database project including: • examining documentation, • interviewing, • Group interview, JAD • observing organization in operation, • research, • questionnaires. Which method above is the most commonly used ?

16. Documents

17. Interviews • Most commonly used, and normally most useful, fact-finding technique. • Enables collection of information from individuals face-to-face. • Objectives include finding out facts, verifying facts, clarifying facts, generating enthusiasm, getting end-user involved, identifying requirements, and gathering ideas and opinions.

18. Interview: Advantage/Disadvantage

19. Phases in an Interview • Selecting Interviewees: who to interview • Designing Interview Questions: open ended, closed ended questions, etc. • Preparing for the Interview • Conducting the Interview • Post-Interview Follow-up

20. Preparing for an Interview • Prepare General Interview Plan • List of Question • Anticipated Answers and Follow-Ups • Confirm Areas of Knowledge • Set Priorities in Case of Time Shortage • Prepare the Interviewee • Schedule • Inform of Reason for Interview • Inform of Areas of Discussion

21. Conducting an Interview • Appear professional and unbiased • Record all information • Check on organizational policy regarding tape recording • Be sure you understand all issues and terms • Separate facts from opinions • Give interviewee time to ask questions • Be sure to thank the interviewee • End on time • Tips: Don’t Worry, Be Happy, Pay Attention, Summarize Key Points, Be Succinct, Be Honest, Watch Body Language

22. Post Interview • Prepare Interview Notes • Prepare Interview Report • Look for Gaps and New Questions

23. Observation • Effective technique for understanding system. • Possible to participate in, or watch, a person perform activities to learn about system. • Useful when validity of data collected is in question or when complexity of certain aspects of system prevents clear explanation by end-users. Example: studying how a student learns through VERBAL PROTOCOLS.

24. Adv./Dis. Of Observation

25. Research

26. Questionnaires • Conduct surveys through questionnaires – special-purpose documents that allow facts to be gathered from a large number of people while maintaining some control over their responses. • Two types of questions, namely free-format and fixed-format.

27. Questionnaires

28. JAD or Group Interview ADVANTAGES • one user may get idea from other user. • Avoids redundancy in interview • Saves interviewer’s time DISADVANTAGE one user hogs conversation hierarchical structure of organization may not allow some users to speak freely.

29. Deliverables • Assignments # 5 – 9 • Paper Reference & abstract (summary) Template for a good Paper or Poster • Problem & Motivation • Background & Related Literature • Approach and Uniqueness • Results and Contribution

30. End of Lecture End Of Today’s Lecture.