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  紀錄上下班時間 ( 以前 : 打卡，現在 : ?)  月初薪資發放  在便利商店或零售商店購買東西之後結帳  店員使用什麼工具結帳？ 一個資料庫應用系統  應用程式 ( 結帳、日週月季年報表、 ? 、 ? 、 ?.... )  資料庫  資料庫管理系統  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 OBJECTIVES  Define terms  Explain limitations of conventional file processing  Explain 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 3

4. Chapter 1 © 2013 Pearson Education DEFINITIONS  Database: organized collection of logically related data  Data: stored facts concerning meaningful things, objects and events  Structured: such as name, address, telephone number  Consisting of numbers, text, dates  Stored in tabular form  Unstructured (multimedia): images, video clips, documents  Information: data processed to increase the knowledge of the persons using the data  Metadata ( 中介資料、資料的描述 ): data that describes the properties and context ( 情境 ) of user data (Data about data) 4

5. Chapter 1 © 2013 Pearson Education Examples of Basic Definitions  Data ( 資料 : 資訊的原料 )  raw facts about things, objects, events, etc.  陳春賢是一個華人姓名資訊，陳、春、賢是姓名的原料 ( 中文字 ) ( 陳是姓的原料，春與賢名字的原料 )  Information ( 資訊 )  processed data that has value for decision making  「陳春賢」是一個名字 ( 一份簡單的資訊 )  「資管系」是一個大學系所的名稱 ( 一份簡單的資訊 )  「長庚大學」是一個大學的名稱 ( 一份簡單的資訊 )  「老師」是一種職業的名稱 ( 一份簡單的資訊 )  「陳春賢現在是長庚大學 資管系的老師」是一筆複合的資訊 ( 複合資訊 : 可能由人、事、時、地、物等簡單資訊所組成 ) 5

6. Chapter 1 © 2013 Pearson Education Examples of 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 6

7. 7 Figure 1-1a Data in context Context helps users understand data 7 Chapter 1 © 2013 Pearson Education Converting Data to Information

8. 8 Graphical displays turn data into useful information that managers can use for decision making and interpretation Figure 1-1b Summarized data 8 Chapter 1 © 2013 Pearson Education Converting Data to Information

9. 9 Metadata for Class Roster : Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and data context 9 Chapter 1 © 2013 Pearson Education Metadata Example

10. 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  Lengthy Development Time  Programmers must design their own file formats  Excessive Program Maintenance  80% of information system budget 10

11. 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 ? 11

12. 12 Chapter 1 © 2013 Pearson Education How a network system improves the situation ? (Location 1) (Location 2) Duplicate Data DEF G

13. 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 ? 13

14. Chapter 1 © 2013 Pearson Education SOLUTION: THE DATABASE APPROACH  Central repository of shared data via a network system  Data is managed by a controlling agent  Stored in a standardized, convenient form 14 Requires a Database Management System (DBMS)

15. Chapter 1 © 2013 Pearson Education DATABASE MANAGEMENT YSTEM () DATABASE MANAGEMENT SYSTEM (DBMS) 15 Database application systems 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 Order Filing System Invoicing System Payroll System DBMS Central database Contains employee, order, inventory, pricing, and customer data Database management system Database

16. 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 16

17. 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)  Organizational conflict with the enforcement of data standards (Data definitions, formats, coding, ownership, rights to update) 17

18. 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, 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 to represent relationships 18 entity 1:M*3M:M PK, FK relationship

19. 19 Segment of an enterprise data model Segment of a project-level data model Figure 1-3 Comparison of enterprise and project-level data models 19 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

20. 20 One customer may place many orders, but each order is placed by a single customer 20 Chapter 1 © 2013 Pearson Education one-to-many relationship

21. 21 One order has many order lines; each order line is associated with a single order 21 Chapter 1 © 2013 Pearson Education one-to-many relationship

22. 22 One product can be in many order lines, each order line refers to a single product 22 Chapter 1 © 2013 Pearson Education one-to-many relationship Back

23. 23 Therefore, one order involves many products and one product is involved in many orders 23 Chapter 1 © 2013 Pearson Education many-to-many relationship

24. 24 Chapter 1 © 2013 Pearson Education ( 未交貨訂單 ) Figure 1-4 Enterprise model for Figure 1-2 segments Figure 1-2

25. Chapter 1 © 2013 Pearson Education 25 Figure 1-5 Components of the Database Environment 人員種類 軟體種類 metadata

26. 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 26

27. 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 of organizational data at high level of abstraction  Entity-relationship diagram  Business-oriented descriptions of entity types () (Business function-to-data entity matrix)  Descriptions of Relationships between entities  Business rules (How the business operates) 27

28. 28 FIGURE 1-6 Example : Business function-to-data entity matrix 28 Chapter 1 © 2013 Pearson Education

29. 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) 29

30. Chapter 1 © 2013 Pearson Education SYSTEMS DEVELOPMENT LIFE CYCLE (SEE ALSO FIGURE 1-7) 30 Planning Analysis Physical Design Implementation Maintenance Logical Design Design Iterative nature of system development

31. Chapter 1 © 2013 Pearson Education 31 Planning Analysis Physical Design Implementation Maintenance Logical Design Planning : Purpose : preliminary understanding of a certain business need for database : Deliverable : request for study : Database activity : enterprise data modeling (early conceptual data modeling) SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Planning)

32. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Analysis – Conceptual Data Modeling) 32 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, attributes, and business rules) matrix model

33. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 33 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)

34. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 34 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)

35. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 35 Implementation Purpose : programming, testing, training, installation, documenting Deliverable : operational programs, documentation, training materials Database activity : database implementation, including coded programs, installation, conversion, and documentation SYSTEMS DEVELOPMENT LIFE CYCLE (Step : Implementation)

36. Chapter 1 © 2013 Pearson Education Planning Analysis Physical Design Implementation Maintenance Logical Design 36 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)

37. 37 Prototyping Database Methodology (Figure 1-8) Chapter 1 © 2013 Pearson Education

38. 38 Prototyping Database Methodology (Figure 1-8) (cont.) 38 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.)

41. 41 Prototyping Database Methodology (Figure 1-8) (cont.) 41 Chapter 1 © 2013 Pearson Education

42. Chapter 1 © 2013 Pearson Education DATABASE SCHEMA  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 42

43. 43 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 43 Chapter 1 © 2013 Pearson Education

44. Chapter 1 © 2013 Pearson Education MANAGING PROJECTS  Mainly managing people, time, and cost.  Project A set of planned, 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 44

45. Chapter 1 © 2013 Pearson Education MANAGING PROJECTS ( PEOPLE INVOLVED)  Business analysts  Systems analysts  Database analysts and data modelers  Users  Programmers  Database architects  Data administrators  Project managers  Other technical experts 45

46. 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 46

47. Chapter 1 © 2013 Pearson Education 47 Evolution of Database Technologies (Figure 1-10a )

48. Chapter 1 © 2013 Pearson Education 48 Database Architectures (Figure 1-10b)

49. Chapter 1 © 2013 Pearson Education 49 Database Architectures (Figure 1-10b)

50. Chapter 1 © 2013 Pearson Education 50 Database Architectures (Figure 1-10b) : Database Architectures for Data Warehouse 3-dimensional model 6-dimensional model

51. 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 51

52. 52 Two-tier Database with Local Area Network (Figure 1-11) 52 Chapter 1 © 2013 Pearson Education 1 2

53. 53 Three-tiered Client/Server Database Architecture (Figure 1-12) 53 Chapter 1 © 2013 Pearson Education 應用程式 / 網頁伺服器 A/P : accounts payable A/R : account receivable 1 2 3

54. 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 54

55. 55 FIGURE 1-13 Computer System for Pine Valley Furniture Company 55 Chapter 1 © 2013 Pearson Education

56. 56 Copyright © 2013 Pearson Education