Introduction to Database System Adisak Intana Lecturer Chapter 1: Introduction

Introduction to Database System 2 Table Contents Enterprize, data and information File processing system Database system Information system

Introduction to Database System 3 Enterprize, data and information u An enterprise is a generic term for any resonably self-contained commercial, scientific, technical, or other organization. u Examples of enterprize : university, department store, hospital, sale product company

Introduction to Database System 4 Enterprize, data and information (Cont.) Business areas and application systems Supplier Order System Sale Product Company Market ing Depart ment Person nel Depart ment IS Depart ment Customer Order System Payro ll Syste m Applications Developme nt System Accoun ting Depart ment Accoun ting Syste m

Introduction to Database System 5 Enterprize, data and information (Cont.) Application systems and application programs Supplie r Order System Application systems Customer Order System Payro ll Syste m Applications Developme nt System Accoun ting Syste m Application programs

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

Introduction to Database System 7 Enterprize, data and information (Cont.) Data and information Da ta Decision Conversi on Reques t Interpre tation Knowle dge Informat ion

Introduction to Database System 8 Enterprize, data and information (Cont.) Data and information Da ta Decision Conversi on Reques t Interpre tation Knowle dge Informat ion

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

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

Introduction to Database System 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.

Introduction to Database System 12 File system ข้อมูลจำนวนไม่มาก อาจสามารถเก็บไว้ในแฟ้ม เอกสาร แยกเป็นเรื่องๆ โดยเนื้อหาที่จัดเก็บในแต่ ละแฟ้มจะเป็นข้อมูลที่เกี่ยวข้องกัน เช่น – แฟ้มข้อมูลคนไข้ของโรงพยาบาล ประกอบด้วยข้อมูล คนไข้ เช่น ชื่อ สกุล ที่อยู่ ประวัติการรักษา เป็นต้น แฟ้ม แต่ละแฟ้มเก็บข้อมูลคนไข้หนึ่งคน – แฟ้มข้อมูลพนักงานขององค์กร ประกอบด้วย ประวัติ พื้นฐานของบุคลากร ประวัติการทำงาน เงินเดือน เป็นต้น การเก็บแฟ้มข้อมูลพนักงานอาจจะมีการแยกกลุ่ม แฟ้มข้อมูลไปตามแผนก และเรียงลำดับแฟ้มตามชื่อ สกุลของพนักงานเพื่อความสะดวกในการสืบค้นข้อมูล

Introduction to Database System 13 File system (Cont.) การเก็บข้อมูลด้วยคอมพิวเตอร์ในช่วงแรกเริ่ม เป็น การเลียนแบบการทำงานด้วยมือ นั่นคือนำเอกสาร ต่างๆมาพิมพ์เก็บไว้ในคอมพิวเตอร์ และมีการ จัดเก็บแยกเป็นแฟ้มข้อมูล แต่ละแฟ้มข้อมูลเก็บ ข้อมูล 1 เรื่อง เรียกว่า “ ระบบแฟ้มข้อมูล ” (File system)

Introduction to Database System 14 File System (Cont.)

Introduction to Database System 15 File system (Cont.)

Introduction to Database System 16 Drawback of file system Uncontrolled duplication of data (data redundancy) p Wastes space p Hard to update all files p Inconsistent data

Introduction to Database System 17 Sales Department Sales Person file PersonalDepartment Employee file Drawback of file system (Cont.)

Introduction to Database System 18 Sales Department Sales Person file PersonalDepartment Employee file Hard to update Wastes space Inconsistent Drawback of file system (Cont.)

Introduction to Database System 19 Drawback of file system (Cont.) Inflexibility p Hard to access unexpected information p Excessive programs maintenance

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

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

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

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

Introduction to Database System 24 Database system Database CUSTOMER EMPLOYEE SALE Staff recruitment system Customers’ orders system Sales accounting system Sales Department Personal Department

Introduction to Database System 25 Database Processing The main problem of database processing is security of data in the database is.

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

Introduction to Database System 27 Database Processing using DBMS Not allow any application program directly access the database.

Introduction to Database System 28 Information system environment DATABASE Transaction processing system Decision support system Expert system Management informaion system

Introduction to Database System 29 Information System 1. Transaction Processing System (TPS) 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.

Introduction to Database System 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. Information System (Cont.)

Introduction to Database System 31 Examples: TPS

Introduction to Database System 32 Examples: TPS (Cont.)

Introduction to Database System 33 Examples: MIS

Introduction to Database System 34 Database system environment Database administration DBMS Data planning & modeling methodology Users Databa se