WinYvain

April 26, 2009

Seventh Quiz : NORMALIZATION

Filed under: ADSI — winyvain @ 2:51 pm

Database Normalization

Normalization process is the establishment of the database structure so that most of the ambiguity can be removed. Normalization stage, starting from the most mild (1NF) to most stringent (5NF) usually only reach the level of 3NF or BCNF because already sufficient to generate the table-a table of good quality.


Why do normalization?
1. Optimizing table structures
2. Increase speed
3. The income data is the same
4. More efficient of storage media
5. Reduce redundancy
6. Avoid anomalies (insertion anomalies, deletion anomalies, update anomalies).
7. Improved data integrity

A table saying good (efficient) or if normal meet 3 criteria:
1. If there is decomposition (decomposition) table, it must be guaranteed safe decomposition (Lossless-Join Decomposition). That is, after the table is described for a new table-table, the table-table can  generate a new table with the same exact.
2. Maintain dependence on the functional changes in data (Dependency preservation).
3. Does not violate Boyce-Code Normal Form (BCNF)

If the three criteria (BCNF) can not be met, then at least the table does not violate the Normal Form of the third stage (3rd Normal Form / 3NF).

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April 4, 2009

Fifth Quiz : DATA FLOW DIAGRAM (DFD)

Filed under: ADSI — winyvain @ 1:18 pm

DEFINITION
Structured approach to the design starting from early 1970. Structured approach, complete with tools and needed techniques in the development of the system, so that the final results of the system will be developed in a system with well defined structure and clear.

Through structured, complex problems can be solved in the organization and results of the system will easy to maintain, flexible, more satisfied users, have any documentation of good, timely, according to the budget cost of development, can improve productivity and quality will be better (free error).

DFD is a logical data model or process that is made to describe the origin of the data and the destination where the data out of the system, where data is stored, the process that produces the data and the interaction between the data stored and the process is imposed on data.

DFD are often used to describe a system that already exists or the new system will be developed logically without considering the physical environment where the data flows, or where data are stored and the user is easy to understand to understand the field of computer systems that will be done.

DFD is a tool that system design-oriented data flow with the concept of decomposition can be used for the delineation and analysis of system design that is easily communicated to the system by the professional user and the program.

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March 29, 2009

Fourth Quiz :INITIAL INVESTIGATION, REQUIREMENT ANALYSIS

Filed under: ADSI — winyvain @ 2:15 pm

Development of a system is often caused by problems that often appear as the performance of the system is less good. For matters like this are usually top management to request assistance analais a system to conduct investigations on their system for the crab from the system they have and determine solutions. Of recommendations given by the system analyst, the top management can decide whether to develop a system that already exists or create a new system better than the previous system.
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March 8, 2009

INFORMATION SYSTEM

Filed under: ADSI — winyvain @ 4:22 pm

1. What is the importance of developing an information system?
2. What is the purpose or goal of developing an information system?
3. What are the organization’s expectations after implementing an information system?
4. What are the principles of developing an information system?
5. Please explain at least three system development life cycle models
6. Please explain approaches of developing a system
7. Please explain the meaning of methodology, method and algorithm
8. Please explain the three classifications of development methodology
9. Please mention tools for developing a system
10. Please explain techniques used in developing a system
11. Please explain the differences of being a system analyst and a programmer and also

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February 21, 2009

Summary of the Basic Concept of The Analysis and Information System Design

Filed under: ADSI — winyvain @ 2:09 pm

Before learn more about the analysis and information system design, there are some basic concepts that we must comprehended before. The concepts are :

  • What is The System ?
  • What is The Information ?
  • What is The Information System ?
  • Who is involve in The Information System?
  • Why The Information is needed ?
  • How is the way to develop the Information System ?

But we only study about the meaning of the information in this first class. For more explaination will explained as following :

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