1. CHAPTER 1: THE DATABASE ENVIRONMENT AND DEVELOPMENT PROCESS Modern Database Management 11 th Edition, International Edition Jeffrey A. Hoffer, V. Ramesh, Heikki Topi © 2013 Pearson Education 1

2. 工作流程的自動化與優化  中鋼薪資發放流程的案例  上下班的簽到簽退管理 ( 以前 : 打卡，現在 : ?)  薪資發放  便利商店或零售商店的營運管理案例  店員使用什麼工具結帳？ 一個資料庫應用系統  資料庫  資料庫管理系統  應用程式 ( 結帳、庫存管理、訂貨、.... )  生活有哪些零售業 ? 資料庫應用系統使用的好處與案例 2

3. Chapter 1 © 2013 Pearson Education Chapter Outline  Basic Concepts and Definitions  Traditional File Processing Systems  The Database Approach  Components of the Database Environment  The Database Development Process  Evolution of Database Systems  The Range of Database Applications  Example of Developing a Database Application 3

4. Chapter 1 © 2013 Pearson Education Learning Objectives To be able to  Understand definitions of terms ( 專門名詞 )  Understand limitations of conventional file processing  Understand advantages of databases  Identify costs and risks of databases  List components of database environment  Identify categories of database applications  Describe life cycle of database system development  Explain prototyping and development approaches  Explain the three-schema architecture for databases 4

5. Chapter 1 © 2013 Pearson Education Definitions  Database: an organized collection of logically related data  Data (item) : stored facts concerning meaningful people, things, events, places, and objects  Structured: such as name, address, telephone number  Consisting of numbers, text, dates  Stored in tabular form  Unstructured (multimedia): images, video clips, documents  Information: (complex) data processed to increase the knowledge of the persons using the data  Metadata (Data about data 資料的描述、中介資料 ): data that describes the properties and context ( 情境 ) of user data 5 Example

6. Chapter 1 © 2013 Pearson Education Basic Definitions  Data ( 資料 : 資訊的原料 )  raw facts about people, things, events, places, and objects etc.  「陳春賢」是一個華人的姓名資料  「資管系」是一個大學系所的名稱資料  「長庚大學」是一個大學的名稱資料  「老師」是一種職業的名稱資料  Information ( 資訊 )  processed data that has value for decision making ( 資訊 : 由人、事、時、地、物等多個資料項目所組合而成 )  例如 : 「陳春賢現在是長庚大學 資管系的老師」是一筆由多項資 料組合而成的資訊 6

7. Chapter 1 © 2013 Pearson Education Basic Definitions  資料庫是由  一堆邏輯相關的資料和  資料的描述所組成  所謂邏輯相關  當我們針對一個機構的資訊需要，而建置一個資料庫時，所儲存 的是與機構營運有關的資料， 例如  某一大學的系所、各系所的學生、課程 、老師 等  某一公司的產品、 客戶、訂單 、製造、 品管、出貨、庫存等  所謂資料的描述  為了要管理這些邏輯相關的資料，資料庫會儲存為了達到管理的 目的而延伸出來的中介資料 (meta data) 。  常稱為「系統目錄」 (system catalog) ，或是「資料字典」 (data dictionary) ，如資料表的名稱、欄位名稱、欄位個數、資料筆數 7

8. 8 Figure 1-1a Data in context ( 背景、前後文 ) Context helps users understand data 8 Chapter 1 © 2013 Pearson Education Converting Data to Information context data records

9. 9 Graphical displays turn data into useful information that managers can use for decision making and interpretation Figure 1-1b Summarized data 9 Chapter 1 © 2013 Pearson Education Converting Data to Information trend

10. 10 Metadata for Class Roster : Descriptions of data properties or characteristics, including data types, field sizes, allowable values, and data source 10 Chapter 1 © 2013 Pearson Education Metadata Example Data report

11. Chapter 1 © 2013 Pearson Education Disadvantages of File Processing Systems  Program-Data Dependence  All programs maintain metadata for each file they use  Duplication of Data (Data redundancy)  Different systems/programs have separate copies of the same data  Limited Data Sharing  No centralized ( 集中化的 ) control of data  Excessive Program Maintenance  80% of information system budget  Lengthy Development Time  Programmers must design their own file formats 11 metadata example

12. Chapter 1 © 2013 Pearson Education Problems with Data Dependency  Each application programmer must maintain his/her own metadata  Each application program  needs to include code for the metadata of each data file  must have its own processing routines for reading, inserting, updating, and deleting data  Lack of coordination and central control  Non-standard file formats  Suppose the length of a field in the file is to be changed. What to do ? 12

13. 13 Chapter 1 © 2013 Pearson Education How a network system improves the situation ? (Location 1) (Location 2) Duplicate Data DEF G duplicate data file

14. Chapter 1 © 2013 Pearson Education Problems with Data Redundancy  Waste of disk space to have duplicate data  Causes more maintenance headaches  The biggest problem:  Data changes in one file could cause inconsistencies  Compromises in data integrity  Suppose some of the data are to be changed. What to do ? 14

15. Chapter 1 © 2013 Pearson Education SOLUTION: The DATABASE Approach  A central repository ( 集中化的儲藏庫 ) of shared data via a network system  Data is managed by a controlling agent  Stored in a standardized, convenient form 15 a Database Management System (DBMS)

16. Chapter 1 © 2013 Pearson Education Database Management ystem () Database Management System (DBMS) 16 A software system that is used to create, manage, and provide controlled access to user databases DBMS manages data resources like an operating system manages hardware resources Database application systems Order Filing System ( 訂單開立系統 ) Invoicing System ( 發票開立系統 ) Payroll System ( 薪資管理系統 ) DBMS Central database Contains employee, order, inventory, pricing, and customer data Database management system Database

17. Chapter 1 © 2013 Pearson Education Advantages of the Database Approach  Program-data independence  Improved data sharing  Planned data redundancy  Enforcement of data standards  Improved data consistency  Improved data quality  Improved decision support  Increased application development productivity  Reduced program maintenance  Improved data accessibility and responsiveness 17 Data dependency Traditional system

18. Chapter 1 © 2013 Pearson Education Costs and Risks of the Database Approach  New, specialized personnel (hiring and training to adopt new DBMS technology)  Installation and management cost and complexity (A networked, multi-user environment may need software/hardware upgrades)  Conversion costs (Re-write database application programs)  Need for explicit backup and recovery utilities (Having only a copy of central database when damage occurs)  Conflict among organizational departments with the enforcement of data standards (Data definitions, formats, coding, ownership, rights to update) 18

19. Chapter 1 © 2013 Pearson Education Elements of the Database Approach  Data models Models capturing the nature and relationship of data  Enterprise Data Model–high-level entities and relationships for the organization  Project Data Model–with additional level of details for implementation, including data structures in database  Entities  describing a person, place, object, event, or concept  Composed of attributes  Relationships  Between entities, relating entities  Usually one-to-many (1:M) or many-to-many (M:N)  Relational Databases  Database technology using tables (relations) to represent entities and primary/foreign keys (PK & FK) to represent relationships 19 entity 1:M*3M:M PK, FK relationship

20. 20 Part of an enterprise data model Part of a project-level data model Figure 1-3 Comparison of enterprise and project-level data models 20 Chapter 1 © 2013 Pearson Education (Includes only the higher-level relationships of customer, order and product entities) (Includes additional level of details) 解決顧客同 名的問題 解決同一顧 客下多張訂 單的問題 解決同一張 訂單訂多項 產品的問題 Entities FK PK Relationships

21. 21 One customer may place many orders, but each order is placed by a single customer 21 Chapter 1 © 2013 Pearson Education one-to-many relationship Example of One-to-Many Relationship - 1/3 Next

22. 22 One order has many order lines; each order line is associated with a single order 22 Chapter 1 © 2013 Pearson Education one-to-many relationship Example of One-to-Many Relationship - 2/3 Next

23. 23 One product can be in many order lines, each order line refers to a single product 23 Chapter 1 © 2013 Pearson Education one-to-many relationship Back Example of One-to-Many Relationship - 3/3

24. 24 One order involves many products and one product is involved in many orders 24 Chapter 1 © 2013 Pearson Education many-to-many relationship Example of Many-to-Many Relationship

25. 25 Chapter 1 © 2013 Pearson Education ( 未交貨項目 ) Figure 1-4 Enterprise model for Figure 1-2 Figure 1-2

26. Chapter 1 © 2013 Pearson Education 26 Figure 1-5 Components of the Database Environment 人員種類 軟體種類 metadata component details

27. Chapter 1 © 2013 Pearson Education Components of DB Environment  Database Management System (DBMS) – software for managing the database  Database – storehouse of the data  Application Programs – software using the data  CASE Tools – for designing database and applications (Computer-Aided Software Engineering)  User Interface – text and graphical displays to users  Repository – centralized storehouse of metadata  Data/Database Administrators – personnel responsible for maintaining the database  System Developers – personnel responsible for designing databases and database application programs  End Users – people who use the applications and databases 27

28. Chapter 1 © 2013 Pearson Education Enterprise Data Model  First step in the database development process  Specifies scope and general content of the databases  Overall picture ( 整體景象 ) of organizational data at high level of abstraction Contains  A high-level entity-relationship diagram () (Descriptions of relationships between entities)  Business-oriented ( 事務導向的 ) description of entity types () (Using business function-to-data entity matrix)  Business rules (How the business operates) 28

29. 29 FIGURE 1-6 Example : Business function-to-data entity matrix 29 Chapter 1 © 2013 Pearson Education

30. Chapter 1 © 2013 Pearson Education TWO MAIN APPROACHES TO DATABASE DEVELOPMENT PROCESS  SDLC ( 系統開發生命週期法 )  System Development Life Cycle (SDLC)  Detailed, well-planned development process  Time-consuming, but comprehensive  Long development cycle  Prototyping ( 雛型開發法 )  One of RAD (Rapid Application Development) methods  Cursory ( 粗略的 ) attempt at conceptual data modeling  Define database during development of initial prototype  Repeat implementation and maintenance activities with new prototype versions (iterative development process) 30

31. Chapter 1 © 2013 Pearson Education SYSTEMS DEVELOPMENT LIFE CYCLE (SEE ALSO FIGURE 1-7) 31 Planning Analysis Physical Design Implementation Maintenance Logical Design Design Iterative nature of system development

32. Chapter 1 © 2013 Pearson Education 32 Planning Analysis Physical Design Implementation Maintenance Logical Design Planning : Purpose : preliminary understanding of a certain business need ( 事務需求 ) for database : Deliverable : request for study : Database activity : enterprise data modeling (early conceptual data modeling) SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Planning)

33. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Analysis – Conceptual Data Modeling) 33 Analysis Purpose : thorough data requirements analysis and structuring Deliverable : functional ( 功能性的 ) system specifications Database activity : thorough and integrated conceptual data modeling (project data modeling : entities, relationships, PK, FK, and attributes) matrix model

34. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 34 Logical Design Purpose : Converting the conceptual schema into a logical schema Deliverable : detailed design specifications (If relational model : tables, columns, PKs, FKs, constraints) Database activity : logical database design (I/O formats, transactions, reports, displays, inquiries, data integrity and security) SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Logical Database Design)

35. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 35 Physical Design Purpose : develop software/hardware and organizational specifications Deliverable : program/data structures, software/hardware purchases, organization redesigns Database activity : physical database design (define database to certain DBMS, physical data organization, database processing programs) SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Physical Database Design & Deifition)

36. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 36 Implementation Purpose : programming, testing, training, installation, documenting Deliverable : operational programs, documentation, training materials Database activity : database implementation, including coded programs, documentation, installation and conversion SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Implementation)

37. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 37 Maintenance Purpose : monitor, repair, enhance Deliverable : periodic audits ( 稽核報表 ) Database activity : database maintenance, performance analysis and tuning, error corrections SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Maintenance)

38. 38 Prototyping Database Methodology (Figure 1-8) Chapter 1 © 2013 Pearson Education

39. 39 Prototyping Database Methodology (Figure 1-8) (cont.) 39 Chapter 1 © 2013 Pearson Education

40. 40 Prototyping Database Methodology (Figure 1-8) (cont.) 40 Chapter 1 © 2013 Pearson Education

41. 41 Prototyping Database Methodology (Figure 1-8) (cont.)

42. 42 Prototyping Database Methodology (Figure 1-8) (cont.) 42 Chapter 1 © 2013 Pearson Education

43. Chapter 1 © 2013 Pearson Education Database Schema ( 概要、草圖 )  External Schema  User Views  Subsets of Conceptual Schema  Can be determined from business-function/data entity matrices  DBA determines schema for different users  Conceptual Schema  E-R models–covered in Chapters 2 and 3  Internal Schema  Logical structures–covered in Chapter 4  Physical structures–covered in Chapter 5 43 matrix

44. 44 Different people have different views of the database…these are the external schema The internal schema is the underlying design and implementation Figure 1-9 Three-schema architecture 44 Chapter 1 © 2013 Pearson Education

45. Chapter 1 © 2013 Pearson Education Managing Projects Database Development Project  Project : A planned undertaking ( 工作 ) of related activities to reach an objective that has a beginning and an end  Initiated and planned in planning stage of SDLC  Executed during analysis, design, and implementation  Closed at the end of implementation 45

46. Chapter 1 © 2013 Pearson Education Managing Projects: People Involved  Business analysts ( 事務分析師、作業分析師 )  Systems analysts  Database analysts and data modelers  Users  Programmers  Database architects  Data administrators  Project managers  Other technical experts 46

47. Chapter 1 © 2013 Pearson Education Evolution of Database Systems  Driven by four main objectives:  Need for program-data independence  reduced maintenance  Desire to manage more complex data types and structures  Ease of data access for less technical personnel  Need for more powerful decision support platforms 47

48. Chapter 1 © 2013 Pearson Education 48 Figure 1-10a Evolution of database technologies

49. Chapter 1 © 2013 Pearson Education 49 Figure 1-10b Database architectures

50. Chapter 1 © 2013 Pearson Education 50 Figure 1-10b Database architectures (cont.)

51. Chapter 1 © 2013 Pearson Education 51 Figure 1-10b Database architectures (cont.)

52. Chapter 1 © 2013 Pearson Education The Range of Database Applications  Personal databases  Two-tier and N-tier Client/Server databases  Enterprise applications  Enterprise resource planning (ERP) systems  Data warehousing implementations 52

53. 53 Figure 1-11 Two-tier database with local area network 53 Chapter 1 © 2013 Pearson Education

54. 54 Figure 1-12 Three-tiered client/server database architecture 54 Chapter 1 © 2013 Pearson Education

55. Chapter 1 © 2013 Pearson Education Enterprise Database Applications  Enterprise Resource Planning (ERP)  Integrate all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources)  Data Warehouse  Integrated decision support system derived from various operational databases ( 營運的 資料庫 ) 55

56. 56 FIGURE 1-13 Computer System for Pine Valley Furniture Company 56 Chapter 1 © 2013 Pearson Education

57. 57 Copyright © 2013 Pearson Education