Database System Introduction to Database Environment October 31, 2009 Software Park, Bangkok Thailand Pree Thiengburanathum College of Arts and Media Chiang Mai University 1 Pree Thiengburanathum, CAMT, Chiang Mai University

About Instructor Pree Thiengburanathum Professional Background Full time lecturer at Chiang Mai University. Java and Web Programmer, TEC center, Fort Collins USA. Education Background PhD. Student Chiang Mai University/University Lyon2, France. M.S. Computer Science, University of Colorado, USA. B.S. Computer Science, Colorado State University, USA. Pree Thiengburanathum, CAMT, Chiang Mai University 2

References/Recommend books [1] G. Silberschatz, Korth, Database System Concept 5 edition [2] Jeffrey A. Hoffer, Marry B.,Modern Database Management 6 th Edition [3] Ramez Elmasri, Shamkant B. Navathe, Fundamentals of Database Systems 5th Edition Pree Thiengburanathum, CAMT, Chiang Mai University 3

4 Objectives Definition of terms Definition of terms Explain growth and importance of databases Explain growth and importance of databases Name limitations of conventional file processing Name limitations of conventional file processing Identify five categories of databases Identify five categories of databases Explain advantages of databases Explain advantages of databases Identify costs and risks of databases Identify costs and risks of databases List components of database environment List components of database environment Describe evolution of database systems Describe evolution of database systems Pree Thiengburanathum, CAMT, Chiang Mai University

5 Definitions Database: organized collection of logically related data Database: organized collection of logically related data Data: stored representations of meaningful objects and events Data: stored representations of meaningful objects and events – Structured: numbers, text, dates – Unstructured: images, video, documents Information: data processed to increase knowledge in the person using the data Information: data processed to increase knowledge in the person using the data Metadata: data that describes the properties and context of user data Metadata: data that describes the properties and context of user data Pree Thiengburanathum, CAMT, Chiang Mai University

6 Figure 1-1a Data in context Context helps users understand data Pree Thiengburanathum, CAMT, Chiang Mai University

7 Graphical displays turn data into useful information that managers can use for decision making and interpretation Figure 1-1b Summarized data Pree Thiengburanathum, CAMT, Chiang Mai University

8 Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and data context Pree Thiengburanathum, CAMT, Chiang Mai University

9 Disadvantages of File Processing Program-Data Dependence Program-Data Dependence – All programs maintain metadata for each file they use Duplication of Data Duplication of Data – Different systems/programs have separate copies of the same data Limited Data Sharing Limited Data Sharing – No centralized control of data Lengthy Development Times Lengthy Development Times – Programmers must design their own file formats Excessive Program Maintenance Excessive Program Maintenance – 80% of information systems budget Pree Thiengburanathum, CAMT, Chiang Mai University

10 Problems with Data Dependency Each application programmer must maintain his/her own data Each application programmer must maintain his/her own data Each application program needs to include code for the metadata of each file Each application program needs to include code for the metadata of each file Each application program must have its own processing routines for reading, inserting, updating, and deleting data Each application program must have its own processing routines for reading, inserting, updating, and deleting data Lack of coordination and central control Lack of coordination and central control Non-standard file formats Non-standard file formats Pree Thiengburanathum, CAMT, Chiang Mai University

11 Figure 1-3 Old file processing systems at Pine Valley Furniture Company Duplicate Data Pree Thiengburanathum, CAMT, Chiang Mai University

12 Problems with Data Redundancy Waste of space to have duplicate data Waste of space to have duplicate data Causes more maintenance headaches Causes more maintenance headaches The biggest problem: The biggest problem: – Data changes in one file could cause inconsistencies – Compromises in data integrity Pree Thiengburanathum, CAMT, Chiang Mai University

13 SOLUTION: The DATABASE Approach Central repository of shared data Central repository of shared data Data is managed by a controlling agent Data is managed by a controlling agent Stored in a standardized, convenient form Stored in a standardized, convenient form Requires a Database Management System (DBMS) Pree Thiengburanathum, CAMT, Chiang Mai University

14 Database Management System DBMS manages data resources like an operating system manages hardware resources A software system that is used to create, maintain, and provide controlled access to user databases Order Filing System Invoicing System Payroll System DBMS Central database Contains employee, order, inventory, pricing, and customer data Pree Thiengburanathum, CAMT, Chiang Mai University

15 Advantages of the Database Approach Program-data independence Program-data independence Planned data redundancy Planned data redundancy Improved data consistency Improved data consistency Improved data sharing Improved data sharing Increased application development productivity Increased application development productivity Enforcement of standards Enforcement of standards Improved data quality Improved data quality Improved data accessibility and responsiveness Improved data accessibility and responsiveness Reduced program maintenance Reduced program maintenance Improved decision support Improved decision support Pree Thiengburanathum, CAMT, Chiang Mai University

16 Costs and Risks of the Database Approach New, specialized personnel New, specialized personnel Installation and management cost and complexity Installation and management cost and complexity Conversion costs Conversion costs Need for explicit backup and recovery Need for explicit backup and recovery Organizational conflict Organizational conflict Pree Thiengburanathum, CAMT, Chiang Mai University

17 Elements of the Database Approach Data models Data models – Graphical system capturing nature and relationship of data – Enterprise Data Model–high-level entities and relationships for the organization – Project Data Model–more detailed view, matching data structure in database or data warehouse Relational Databases Relational Databases – Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships Use of Internet Technology Use of Internet Technology – Networks and telecommunications, distributed databases, client- server, and 3-tier architectures Database Applications Database Applications – Application programs used to perform database activities (create, read, update, and delete) for database users Pree Thiengburanathum, CAMT, Chiang Mai University

18 Segment of an Enterprise Data Model Segment of a Project-Level Data Model Pree Thiengburanathum, CAMT, Chiang Mai University

19 One customer may place many orders, but each order is placed by a single customer  One-to-many relationship Pree Thiengburanathum, CAMT, Chiang Mai University

20 One order has many order lines; each order line is associated with a single order  One-to-many relationship Pree Thiengburanathum, CAMT, Chiang Mai University

21 One product can be in many order lines, each order line refers to a single product  One-to-many relationship Pree Thiengburanathum, CAMT, Chiang Mai University

22 Therefore, one order involves many products and one product is involved in many orders  Many-to-many relationship Pree Thiengburanathum, CAMT, Chiang Mai University

23 Figure 1-4 Enterprise data model for Figure 1-3 segments Pree Thiengburanathum, CAMT, Chiang Mai University

24 Figure 1-5 Components of the Database Environment Pree Thiengburanathum, CAMT, Chiang Mai University

25 Components of the Database Environment CASE Tools – computer-aided software engineering CASE Tools – computer-aided software engineering Repository – centralized storehouse of metadata Repository – centralized storehouse of metadata Database Management System (DBMS) – software for managing the database Database Management System (DBMS) – software for managing the database Database – storehouse of the data Database – storehouse of the data Application Programs – software using the data Application Programs – software using the data User Interface – text and graphical displays to users User Interface – text and graphical displays to users Data/Database Administrators – personnel responsible for maintaining the database Data/Database Administrators – personnel responsible for maintaining the database System Developers – personnel responsible for designing databases and software System Developers – personnel responsible for designing databases and software End Users – people who use the applications and databases End Users – people who use the applications and databases Pree Thiengburanathum, CAMT, Chiang Mai University

26 The Range of Database Applications Personal databases Personal databases Workgroup databases Workgroup databases Departmental/divisional databases Departmental/divisional databases Enterprise database Enterprise database Pree Thiengburanathum, CAMT, Chiang Mai University

27 Pree Thiengburanathum, CAMT, Chiang Mai University

28 Figure 1-6 Typical data from a personal database Pree Thiengburanathum, CAMT, Chiang Mai University

29 Figure 1-7 Workgroup database with wireless local area network Pree Thiengburanathum, CAMT, Chiang Mai University

30 Enterprise Database Applications Enterprise Resource Planning (ERP) Enterprise Resource Planning (ERP) – Integrate all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources) Data Warehouse Data Warehouse – Integrated decision support system derived from various operational databases Pree Thiengburanathum, CAMT, Chiang Mai University

31 Figure 1-8 An enterprise data warehouse Pree Thiengburanathum, CAMT, Chiang Mai University

32 Evolution of DB Systems Pree Thiengburanathum, CAMT, Chiang Mai University