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Introduction to Database System

Introduction to Database System. Adisak Intana Lecturer. Chapter 1: Introduction. Table Contents. Enterprize, data and information File processing system Database system Information system. Enterprize, data and information.

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Introduction to Database System

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  1. Introduction to Database System Adisak Intana Lecturer Chapter 1: Introduction

  2. Table Contents Enterprize, data and information File processing system Database system Information system 2

  3. Enterprize, data and information • An enterpriseis a generic term for any resonably self-contained commercial, scientific, technical, or other organization. • Examples of enterprize : university, department store, hospital, sale product company 3

  4. Enterprize, data and information (Cont.) Businessareas and application systems Sale Product Company Accounting Department Marketing Department Personnel Department IS Department Supplier Order System Customer Order System Payroll System Applications Development System Accounting System 4

  5. Enterprize, data and information (Cont.) Applicationsystems and application programs Supplier Order System Customer Order System Payroll System Applications Development System Accounting System Application systems Application programs 5

  6. Enterprize, data and information (Cont.) Data Processing Application program & data Data processing Information 6

  7. Enterprize, data and information (Cont.) Data and information Data Information Decision Conversion Request Knowledge Interpretation 7

  8. Enterprize, data and information (Cont.) Data and information Data Information Decision Conversion Request Knowledge Interpretation 8

  9. Data and information • Often the terms dataand information are used interchangeably, but they are different. • Data are raw, unsummarized, and unanalyzed facts. • Information is data that have been processed into meaningful form. 9

  10. Information system An information system is a system that supplies the information needed by an organization or enterprise. 10

  11. Data processing • Most application programs need to store data that can be retrieved later. • Most programming languages have the ability to create and store data in separate files. 11

  12. File system • ข้อมูลจำนวนไม่มาก อาจสามารถเก็บไว้ในแฟ้มเอกสาร แยกเป็นเรื่องๆ โดยเนื้อหาที่จัดเก็บในแต่ละแฟ้มจะเป็นข้อมูลที่เกี่ยวข้องกัน เช่น • แฟ้มข้อมูลคนไข้ของโรงพยาบาล ประกอบด้วยข้อมูลคนไข้ เช่น ชื่อ สกุล ที่อยู่ ประวัติการรักษา เป็นต้น แฟ้มแต่ละแฟ้มเก็บข้อมูลคนไข้หนึ่งคน • แฟ้มข้อมูลพนักงานขององค์กร ประกอบด้วย ประวัติพื้นฐานของบุคลากร ประวัติการทำงาน เงินเดือน เป็นต้น การเก็บแฟ้มข้อมูลพนักงานอาจจะมีการแยกกลุ่มแฟ้มข้อมูลไปตามแผนก และเรียงลำดับแฟ้มตามชื่อ สกุลของพนักงานเพื่อความสะดวกในการสืบค้นข้อมูล 12

  13. File system (Cont.) • การเก็บข้อมูลด้วยคอมพิวเตอร์ในช่วงแรกเริ่ม เป็นการเลียนแบบการทำงานด้วยมือ นั่นคือนำเอกสารต่างๆมาพิมพ์เก็บไว้ในคอมพิวเตอร์ และมีการจัดเก็บแยกเป็นแฟ้มข้อมูล แต่ละแฟ้มข้อมูลเก็บข้อมูล 1 เรื่อง เรียกว่า “ระบบแฟ้มข้อมูล” (File system) 13

  14. File System(Cont.) 14

  15. File system (Cont.) 15

  16. Drawback of file system • Uncontrolled duplication of data (data redundancy) • Wastes space • Hard to update all files • Inconsistent data 16

  17. Sales Department Personal Department Employee file Sales Person file Drawback of file system (Cont.) 17

  18. Sales Department Personal Department Employee file Sales Person file Drawback of file system (Cont.) Wastes space Hard to update Inconsistent 18

  19. Drawback of file system (Cont.) • Inflexibility • Hard to access unexpected information • Excessive programs maintenance 19

  20. Drawback of file system (Cont.) Hard to access unexpected information Sales Department Sales Person file 20

  21. Drawback of file system (Cont.) • Limited data sharing • Same data is scattered in various files which may be in different format. • Difficult to use data from these existing files for new programs 21

  22. Sales Department Personal Department Employee file Sales Person file Integer Character Drawback of file system (Cont.) Difficult to use data from these existing files for new programs Same data may be in Different format 22

  23. Drawback of file system (Cont.) • Data dependence problem • Application programs are dependent upon the structure of files and data structures they processed. • Changes of files and/or data structures result in recompiling the application programs. 23

  24. Personal Department CUSTOMER EMPLOYEE Staff recruitment system SALE Sales Department Customers’ orders system Sales accounting system Database system Database 24

  25. Database Processing • The main problem of database processing is security of data in the database is. 25

  26. Personal Department CUSTOMER EMPLOYEE Staff recruitment system DBMS SALE Sales Department Customers’ orders system Sales accounting system Database system Database 26

  27. Database Processingusing DBMS • Not allow any application program directly access the database. 27

  28. Transaction processing system Information systemenvironment Decision support system DATABASE Management informaion system Expert system 28

  29. Information System 1. Transaction Processing System (TPS) An information system that processes an organization’s basic business transaction such as purchasing, billing, and payroll. 2. Management Information System (MIS) System designed to provide past, present, and future routine information appropriate for planning, organizing, and controlling the operations of functional areas in an organization. 29

  30. Information System (Cont.) 3. Decision Support System (DSS) A computer-based information system that combines models and data in an attempt to solve semistuctured problems with extensive user involvement. 4. Expert System (ES) A system that employs human knowledge captured in a computer to solve problem that ordinarity require human expertise. 30

  31. Examples: TPS 31

  32. Examples: TPS(Cont.) 32

  33. Examples: MIS 33

  34. Database systemenvironment DBMS Database administration Database Data planning & modeling methodology Users 34

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