QM Chapter 1 Database Fundamentals Version 10 th Ed. Prepared by Dr Kamel Rouibah / Dept QM & IS

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1 QM Chapter 1 Database Fundamentals Version 10 th Ed Prepared by Dr Kamel Rouibah / Dept QM & IS Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 1

2 Objectives Define terms and review basic concepts related to database management Name 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 database system development life cycle Explain roles of individuals Describe evolution of database systems Introduce students to components of DBMS Explain the three-schema architecture for databases Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 2

3 Process view vs data view (Summary QM 331) Process view Concentrates both on flow, use and transformation of data Focuses on what the system is supposed to do Shows the sequence of steps (activities) Tracks data from source to final destination (output) But, does not specify the structure of data Data view Focuses on the data and its structure the system needs to operate Separates application programs and the data used by programs (e.g. students and students attributes) Approach is independent of where and how data are used in a system Data designed for the whole enterprise QM 433 will focus SOLELY on the data view Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 3

4 BASIC CONCEPTS AND DEFINITIONS Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 4

5 Data hierarchy: Basic definition: Bit, byte, field, record, file and database (summary of past MIS courses) Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 5

g. name, registration, student ID Date: 12 th of February 2013 Unstructured data: multimedia Documents, e.g. a PDF or Word document Maps (see.

6 Basic concepts and definitions: Two types of data Database: organized collection of logically related data Data: stored representations of meaningful objects and events that include structured and unstructured data Structured data Numeric; e.g Characters; e.g. name, registration, student ID Date: 12 th of February 2013 Unstructured data: multimedia Documents, e.g. a PDF or Word document Maps (see. Google Earth) Photographic image Sound Video Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 6

7 Metadata Basic concepts and definitions: Metadata Data that describes the properties or characteristics of end user data and the context of that data Separate data from its properties Metadata enables designers and users to understand: What data exist? What the data mean? What the fine distinctions are between similar data items? Example see MS Access (field properties) Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 7

8 Example of metadata Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 8

of information Data in context Summarized data We can easily recognized

9 Basic concepts and definitions: information Information: data that have been processed to increase knowledge and is useful in decision making Two types of information Data in context Summarized data We can easily recognized class Roster Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 9

10 TRADITIONAL FILE PROCESSING SYSTEMS Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 10

11 Disadvantages of traditional file management Similar disadvantages were seen in chapter 5 (QM 240) and chapter 1 (QM 331) File management a way of collecting and maintaining data in an organization Each functional area (department) creates and maintains its own data files and programs. Files allow the creation of a single database Only one file is accessed at a time Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 11

12 Example of file management: What problems are shown in this figure? Relation Are missing Data is redundant Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 12

13 Disadvantages of traditional file management (cont') Program-data dependence All programs maintain metadata for each file they use Close relationship exists between data stored in traditional files and the software programs that update and maintain those files. Data duplication (redundancy) The presence of duplicate data in multiple data files leads to data (عدم التوافق) inconsistency Waste of space high maintenance costs 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 must have its own processing routines for reading, inserting, updating, and deleting data Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 13

14 Disadvantages of traditional file management (cont') Limited data sharing Information is available in different files and different parts of the organization No centralized control of data; data or information cannot flow freely from one part to another in the organization Length development time Related to previous, there is a need for extra programming efforts to let users access other files not under their control Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 14

High Maintenance cost Excessive program maintenance or lack of flexibility 10% of time are devoted to debugging problems 10% are concerned with changes in data, files, reports, hardware, or system

15 High Maintenance cost Excessive program maintenance or lack of flexibility 10% of time are devoted to debugging problems 10% are concerned with changes in data, files, reports, hardware, or system software. Up to 80% of all maintenance work consists of making user enhancements, improving documentation, and recoding system components for greater processing efficiency. Consume 80% of information systems budget Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 15

The DATABASE Approach Data models Graphical

data See more in chapter 2 and 3 Entities

event, or concept Composed of attributes

binary, ternary) 1-to-1,one-to-many (1:M)

information that describe entities Dr K.

16 The DATABASE Approach Data models Graphical system capturing nature and relationship of data See more in chapter 2 and 3 Entities Noun describing a person, place, object, event, or concept Composed of attributes Relationships Between entities (Unary, binary, ternary) 1-to-1,one-to-many (1:M) or many-to-many (M:N) Attributes Pieces of information that describe entities Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 16

17 The DATABASE Approach Instances Elements that compose entities Types of data models Relational database model: establish relationship between entities using a common field Object model Database application is an application program (or set of related programs) that is used to perform a series of database activities (create, read, update, and delete) on behalf of database users Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 17

18 Database Management System (DBMS) Order Filing System Invoicing System Payroll System DBMS DBMS manages data resources like an operating system manages hardware resources Central database Contains employee, order, inventory, pricing, and customer data DBMS is a software system that is used to create, maintain, and provide controlled access to user database DBMS is used to connect three different database applications Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 18

) Increased application development productivity Enforcement of standards Improved data quality: poor data is a serious problem and

19 Advantages of the Database Approach 19 Program-data independence Planned data redundancy Improved data consistency Improved data sharing: different users views (e.g. students, doctors, etc.) Increased application development productivity Enforcement of standards Improved data quality: poor data is a serious problem and Estimation of TDWI (The Data Warehousing Institute) $600 billions/year Improved data accessibility and responsiveness: no need for programming experience Reduced program maintenance Improved decision support

20 Costs and Risks of the Database Approach New, specialized personnel Database designer, database administrator who needs continuous training Installation and management cost and complexity Software suite such as Oracle need installation, maintenance, upgrade, Conversion costs of legacy system is too high Legacy system are old systems (or databases) that have been in existence for long time ago and the conversion to new databases is too high Need for explicit backup and recovery Corporate databases are needed with almost zero downtime (e.g. Borsa) Organizational conflict Require consensus on issue such as data definition and ownership and 20 responsibilities need strong top management support

21 Components of the database environment Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 21

22 Components of the database environment Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 22

23 Component of the database environment Computer-Aided Software Engineering Tools CASE tools automate curtains design functions, e.g. generate ERD and the code (e.g. MS Visio) Repository Centralized storehouse of metadata, data relationship, screen and report formats, and other system components Include additional metadata to manage databases (see more in chapter 11 Administration) DBMS Used to create, maintain, and provide controlled access to user database Database Collection of data organized to service many applications at the same time by storing and managing data so that they appear to be in one location Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 23

24 Component of the database environment (cont ) Application Programs The software program (or set of related programs) that is used to perform a series of database activities (create, read, update, and delete) on behalf of database users User Interface Text and graphical displays to users Data and Data Administrators (see more in Chapter 11) Personnel responsible to maintain the database System Developers Personnel responsible to design the databases and software (e.g. system analysts and programmers) End Users People who use the applications and databases Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 24

25 The Range of Database Applications Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 25

26 The Range of Database Applications Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 26

27 Personal Database Standalone desktop database designed to support one user E.g. data bases developed by my students in QM 433 Example of key issue management Should the application be purchased from outside vendor or developed inhouse? What commercial DBMS product should be used for the application? Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 27

28 Two-tier A small DB to be used by Workgroup LAN for less than 25 users to share data Support the collaborative efforts of the team using computers connected to a LAN such as developer, system analyst, project manager DB is stored on a computer called database server Each user computer has a copy of a light application that provides him with user interface and business logic (e.g. algorithms that handle information) Example: DB used at our college to book a specific LAB for a specific instructor Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 28

29 Three-tiered database location architecture In large information systems, data may be stored in different computers locations (or tiers) Processing (application) of the data from a database may occur at different locations in order to take advantages of the processing speed, ease of use of programming on different computers platforms too Browser-based interface in conjunction with company database is increasingly used to ease transactions between the web browsers the back-end database Data could reside on a client server, on a application server, on a web server, and on a database server Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 29

30 Three-tiered client/server database architecture Store Applications Store Data related To different application Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 30

31 Enterprise Database Serve the entire organization (or several departments) Organization may have several enterprise DBs Databases used at a large scale (hundreds or thousands of users) It is based on WAN Two major development: ERP and data warehousing systems Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 31

Enterprise Resources Planning (ERP) systems Information systems that integrate and coordinate key internal processes of the firms, integrating data from different

32 Enterprise Resources Planning (ERP) systems Information systems that integrate and coordinate key internal processes of the firms, integrating data from different business functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources) Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 32

Data Warehouse Systems Is a database, with reporting and query tools, that stores current and historical data extracted from various operational systems, for

33 Data Warehouse Systems Is a database, with reporting and query tools, that stores current and historical data extracted from various operational systems, for the entire organization, and consolidated for management reporting and analyzing (e.g. CRM) Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 33

Internet, Intranet and extranet Internet: network of connected computer servers over the world Intranet: private company network accessed only by employees Extranet: Intranet with extended

34 Internet, Intranet and extranet Internet: network of connected computer servers over the world Intranet: private company network accessed only by employees Extranet: Intranet with extended authorization to suppliers and customer Business-to-consumer (B2C) Issues to consider Which technologies to use? Security/privacy protection Managing huge volumes of data from Internet transactions Maintaining data quality Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 34

35 Evolution of database technologies Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 35

36 Types of databases Network DBMS AND Hierarchical DBMS Used to develop first generation of DBMS Appeared in 1970 and several systems continue to be used up to now Difficult to access data, based navigational record-at-a-time procedure Legacy system is a system that has been in existence for a long time (in a mainframe) and that continues to be used to avoid the high cost of replacing or redesigning it (QM 240). Relational DBMS [1980] [General culture] Manage mainly structured data (text and numbers) Received wide commercial acceptance in 1980 Data are represented in tables Easy data access for non programmers through SQL, 4 th generation language Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 36

37 Types of database Object oriented DBMS AND Object relational DBMS (cont ) Used to develop the 3 rd generation of DBMS Appearance and important because of of client/server architecture, data warehousing, and internet applications Large use of structured data (e.g. accounting) and multimedia data and applications (sound, images and videos) Introduced in 1980, but largely accepted in 1990s See more in chapter 14 and 15 Because companies manage vast amount of structured and unstructured data, vendors are developing Object Relational DBMS Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 37

38 The database development process Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 38

System Development Life Cycle Project identification and selection Project initiation and planning Analysis SDLC: the traditional methodology used to develop,

39 System Development Life Cycle Project identification and selection Project initiation and planning Analysis SDLC: the traditional methodology used to develop, maintain, an replace information system Logical design & physical design Implementation Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process Maintenance 39

40 Database development process during SDLC Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 40

41 Enterprise modeling It is performed during the 1 st phase of SDLC Identification and selection Enterprise data model describes the entities in an organization and the relationship between these entities Analyze the current business and determine their needs in term of databases and information systems Review existing information systems and databases Identify what data is available and what other data need to be added to these systems Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 41

42 Enterprise modeling Use Planning Matrix (see next) that describe interrelationships between planning objects Business function to data entities IS-to-data entity IS-to-business objective Output: Select one project for database development Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 42

43 Example of data entity and business function Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 43

44 Exercise Question: Draw the enterprise modeling for CBA by generating the same table as before Remark: the model should include all entities in the present time and the future Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 44

45 Conceptual data modeling (2 nd phase of SDLC- Initiation an planning) System analyst will generate a conceptual data model It is also called conceptual schema or entity relationship diagram (see chapter 2 and 3) The E-R model project highlights only high level categories of data (entities) and major relationships that are useful only for the specific project (not for the enterprise) Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 45

46 Conceptual data modeling (3 rd phase of SDLC-Analysis) Two activities System analyst will specify the conceptual data model i(for the selected project) in term of Attributes of the entities Relationships between the identified entities Specify the rules that dictates the integrity of the data, It is also called conceptual schema Remark: But the E-R model is just a preliminary model since it will be subject of modifications based on subsequent SDLC activities Why: because of missing elements or errors when designing transactions, reports, display or inquiries (see more in the QM 471: project in IS) Conceptual data modeling is a top down process, i.e. it is driven from a general understanding of the business area, and not from specific information processing activities Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 46

47 Logical database design (4 rd phase of SDLC) Two important activities Transform the conceptual data model to a logical data model Logical data model describes the data in term of the data management technology that will be used to implement the database E.g. if a relational technology will be used the transformation process is called normalization (see chapter 4 and 5), i.e. it must be transformed into a relational data model but independent of any database technology Design each computer program in term of Input, output format, reports, display, and inquiries supported by the database Description is made independent from any particular database management system Remark This is a bottom-up analysis, i.e. system analyst verifies exactly what data are to be maintained in the DB and the nature of those data as needed for each transaction, reports, and so forth Logical model might lead to modification of the conceptual data model Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 47

48 Physical database design and definition (5 rd phase of SDLC) It is dependent of the DBMS that will be used to implement the database This task is carried based in coordination with all other aspects of the physical information systems Programs Computer hardware Operating systems Data communication networks System analyst will specify The organization of physical record Choice of file organization (see Three-Tiered database location) Use of indexes Where to store data centralized or decentralized Decision support reports Security, etc Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 48

49 Implementation of the Database (6 rd phase of SDLC) Write, test and install the programs that process the data There are many available programming languages, e.g. Visual Basic can be used to generate high complex MS Access database Produce effective display and reports Finalize the database users documentation Put the database in production Backup the database in order to ovoid losing data Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 49

50 Database maintenance (7 rd phase of SDLC) Modify (add, delete, change) the structure of database Modification is carried out for three reasons: Meet new business requirements Correct errors in the database design, Improve the processing speed of the database applications Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 50

51 Exercise: fill in this table by putting Yes or No / Four important data models in the database All entities? All attributes? Technology independent? DBMS independent? Record Layouts? Enterprise model Conceptual model Logical model Physical model Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 51

52 Alternative information system development approaches (see more in QM 240) SDLC has several disadvantages In house development Rapid Application Development (e.g. Prototyping, see figure 1.11) Prototyping: an iterative process of systems developments in which requirements are converted to a working system that is continually revised through close work between analysts and users Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 52

53 Alternative information system development approaches Agile software development: An approach to database development that emphasizes Individuals and interactions over processes and tools Working software over comprehensive documentation Customer collaboration over contract negotiations, and Response to change over the following a plan Other Alternative information system development approaches Application Software Package: e.g. Oracle Suite Outsourcing Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 53

Three schema architecture view of a manager or external user Different people have different views of the database these are the external schema The internal schema is the

54 Three schema architecture view of a manager or external user Different people have different views of the database these are the external schema The internal schema is the underlying design and implementation View of data architect or data administrator view of a database administrator Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 54

55 Three schema architecture Physical Schema Physical structures Will be covered in chapters 6 and 7 Conceptual Schema E-R models Will be covered in chapters 2 and 3 External Schema (in the lab with Heba) User Views Subsets of Conceptual Schema Can be determined from business-function/data entity matrices DBA determines schema for different users Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 55

56 Managing the People Involved in database development seen in previous courses (QM 240) and (QM 331) Business analyst Systems analysts Database analysts and data modelers End-users Programmers Database architect Data administrators Project managers Other technical experts (Network administrators, security, etc.) Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database development process 56

57 End of chapter 1 Dr K. Rouibah / dept QM & IS Chapter 1 (433) Database fundamentals 57

OBJECTIVES DEFINITIONS CHAPTER 1: THE DATABASE ENVIRONMENT AND DEVELOPMENT PROCESS. Figure 1-1a Data in context

OBJECTIVES DEFINITIONS CHAPTER 1: THE DATABASE ENVIRONMENT AND DEVELOPMENT PROCESS. Figure 1-1a Data in context OBJECTIVES CHAPTER 1: THE DATABASE ENVIRONMENT AND DEVELOPMENT PROCESS Modern Database Management 11 th Edition Jeffrey A. Hoffer, V. Ramesh, Heikki Topi! Define terms! Name limitations of conventional