1. Dr. Chen, Management Information Systems Chapter 5 Database Processing Jason C. H. Chen, Ph.D. Professor of MIS School of Business Administration Gonzaga University Spokane, WA 99258 chen@jepson.gonzaga.edu

2. Dr. Chen, Management Information Systems GearUp Scenarios Chapter 5: Database Processing GearUp does not have the easy access to data needed to analyze vendor quality and costs 2

3. Dr. Chen, Management Information Systems GearUp: “Can You Put the Data into Access?” GearUp needs operating data to analyze for cost- cutting decisions Need to extract and combine data from multiple systems Will use Access to create report In general, what does GearUp need for improving its decisions? Answer - Database processing

4. Dr. Chen, Management Information Systems Businesses of every size organize data records into collections called databases. At one extreme, small businesses use databases to keep track of customers; at the other extreme, huge corporations such as Dell and Amazon.com use databases to support complex sales, marketing, and operations activities. In between, we have businesses like FlexTime that use databases as a crucial part of their operations, but they don’t have a trained and experienced staff to manage and support the databases. To obtain answers to the one-of-a-kind queries he needs, Neil needs to be creative and adaptable in the way that he accesses and uses his database. This chapter discusses the why, what, and how of database processing. We begin by describing the purpose of databases and then explain the important components of database systems. We then overview the process of creating a database system and summarize your role as a future user of such systems. Users have a crucial role in the development of database applications. Specifically, the structure and content of the database depends entirely on how users view their business activity. To build the database, the developers will create a model of that view using a tool called the entity-relationship model. You need to understand how to interpret such models, because the development team might ask you to validate the correctness of such a model when building a system for your use. Finally, we describe the various database administration tasks. This chapter focuses on database technology. Here we consider the basic components of a database and their functions. You will learn about the use of database reporting and data mining in Chapter 9. Chapter Preview 4

5. Dr. Chen, Management Information Systems Study Questions Q1: What is the purpose of a database? Q2: What is a database? Q3: What are the components of a database application system? Q4: How do database applications make databases more useful? Q5: How are data models used for database development? Q6: How is a data model transformed into a database design? Q7: What is the users’ role in the development of databases? Q8: 2022?

6. Dr. Chen, Management Information Systems What is the most important computer resource on the Internet Search Engine (backend)? ?

7. Dr. Chen, Management Information Systems You will learn the following: –1) Database Concepts and –2) Conceptual Database Design (Data Model) Answer: Database

8. Dr. Chen, Management Information Systems Linking Internal Databases to the Web DATABASE TRENDS N 8 Server tier Database tier User tier

9. Dr. Chen, Management Information Systems Web-Based Client/Server Database Architecture Network Web server Database Server Web Browser 5. Retrieved data 4. Data query 7. Data-based Web page 8. Data-based Web page 1. Request for data-based Web page 6. Retrieved data 3. Data query 2. Request for data-based Web page Legend Communications Between Web browser And Web server Communications Between Web server And database server 9

10. Dr. Chen, Management Information Systems TWO TYPES OF DATA PROCESSING FILE-BASED DATA-BASED 10

11. Dr. Chen, Management Information Systems Figure: File-based Approach to Data Processing Checking Account Data Files Auto Loan Data Files Savings Account Data Files Checking Account Programs Savings Account Programs Auto Loan Programs 11

12. Dr. Chen, Management Information Systems Three file processing systems at a company Duplicate Data What is the main problem in the company’s processing systems?

13. Dr. Chen, Management Information Systems Disadvantages of File Processing Program-Data Dependence –All programs maintain metadata for each file they use Data Redundancy (Duplication of data) –Different systems/programs have separate copies of the same data Limited Data Sharing –No centralized control of data Lengthy Development Times –Programmers must design their own file formats Excessive Program Maintenance –80% of of information systems budget 13

14. Dr. Chen, Management Information Systems Questions Question-1: How to overcome most of the problems from File-based data processing? Answer: Data-based approach Question-2: Is MS/Access a database? Answer: No (Why?) Question-3: Then, what is it? You will learn all these concepts in the chapter.

15. Dr. Chen, Management Information Systems Database Management System ??? Database containing centralized shared data Application #1 Application #2 Application #3 15

16. Dr. Chen, Management Information Systems Database Management System DBMS manages data resources like an operating system manages hardware resources DBMS Database containing centralized shared data Application #1 Application #2 Application #3 16

17. Dr. Chen, Management Information Systems As a database user, you play a crucial role in developing database applications for your business or organization. Organize and keep track of things Keep track of multiple themes General rule:  Single theme store in a ____________  Multiple themes require a __________ Q1: What Is the Purpose of a Database? Fig 5-1 List of Student Grades, Presented in a Spreadsheet 17 database spreadsheet

18. Dr. Chen, Management Information Systems Student Data Form With Multiple Themes Fig 5-2 Student Data Shown in a Form, from a Database

19. Dr. Chen, Management Information Systems 5-19 Q2: What is a database? These are terms you’ll need to know when working with databases. –A database is a self-describing collection of integrated records –A database is an organized collection of logically related data files. (different from the text) –Bytes, characters of data, are grouped into columns which are also called fields. –The fields are grouped into rows which are also called records. –A table is a group of similar rows or records which is also called a file. Fig 5-3 Student Table (also called a file) 19

20. Dr. Chen, Management Information Systems Hierarchy of Data Elements Fig 5-4 Hierarchy of Data Elements This figure shows the hierarchy of data elements working from the smallest at the bottom to the largest at the top. 20

21. Dr. Chen, Management Information Systems Components of a Database: Metadata Describes Structure of Database Fig 5-5 Components of a Database A database is more than just a group of tables. It includes tables or files plus the relationships among rows in the tables and metadata that describes the database’s structure. 21

22. Dr. Chen, Management Information Systems 5-22 Metadata Fig 5-7 Sample Metadata (in Access) Metadata are data that describe data and makes databases easy to use. Metadata is always a part of a database. The Field Name, Data Type, and Description at the top of this diagram are part of the database’s metadata. The additional field properties at the bottom are also considered metadata.

23. Dr. Chen, Management Information Systems Fig. 5-6: Example of Relationships Among Rows This diagram shows relationships among rows of different tables. The Student Number value in the first row of the top table,1325, relates to the same Student Number value in a row in the second table. What Are Relationships Among Rows? 23

24. Dr. Chen, Management Information Systems Fig. 5-6: Example of Relationships Among Rows This diagram shows relationships among rows of different tables. The Student Number value in the first row of the top table,1325, relates to the same Student Number value in a row in the second table. Both that Student Number values and that of 4867 (and 1325) in the second table relate to those in the third. What Are Relationships Among Rows? 24

25. Dr. Chen, Management Information Systems Key  A column or group of columns that identifies a unique row in a table.  Student Number is the key of the Student table. Given a value of Student Number, you can determine one and only one row in Student. Only one student has the number 1325.  Every table must have a (primary) key.  Sometimes more than one column is needed to form a unique identifier. In a table called City, for example, the key would consist of combination of columns (City, State) – form a composite key.  Email_Num is the key of Email Table.  VisitID is the key of Office_Visit Table. Relationship Special Terms 25 pk

26. Dr. Chen, Management Information Systems Foreign keys –These are keys of a different (foreign) table than the table in which they reside. – A relational database carries data in the form of tables and uses foreign keys to represent relationships Relational databases  Relationships among tables are created by using foreign keys. Relation  Formal name for a table Relationship Special Terms 26 pk fk pk fk What is (are) the fk in this relation?

27. Dr. Chen, Management Information Systems Study Questions Q1: What is the purpose of a database? Q2: What is a database? Q3: What are the components of a database application system? Q4: How do database applications make databases more useful? Q5: How are data models used for database development? Q6: How is a data model transformed into a database design? Q7: What is the users’ role in the development of databases? Q8: 2022?

28. Dr. Chen, Management Information Systems Applications make database data more accessible and useful. Users employ a database application that consists of forms, formatted reports, queries, and application programs. Database management system (DBMS) processes database tables for applications. Q3: What Are the Components of a Database Application System? Fig 5-8 Components of a Database Application System 28

29. Dr. Chen, Management Information Systems What Is a Database Management System (DBMS)? Database developers use the DBMS to create or modify tables, relationships, and other structures in a database. A DBMS (database management system) program is used to create, process, and administer a database. Popular DBMS products include: Oracle from Oracle Corporation (World #1 Database company) DB2 from IBM Access from Microsoft (for personal computers) SQL Server from Microsoft (for large computer systems) MySQL, an open-source (it was acquired by Oracle) product that’s license-free Don’t confuse a DBMS, which is a software program, with a database, which is a collection of tables, relationships and metadata. But, they are two different concepts. 29

30. Dr. Chen, Management Information Systems Database developers use the DBMS to create and modify tables, relationships, and other structures in the database. Below, the developer has added a new column called Response?. This new column has data type Yes/No. Creating the Database and Its Structures 30 Fig 5-9 Adding a New Column to a Table (in Access)

31. Dr. Chen, Management Information Systems Four DBMS operations  Read,  _______,  modify,  _______ data Applications call DBMS in different ways  From a form, when the user enters new or changed data, a computer program behind the form calls the DBMS to make the necessary database changes.  From an application program, the program calls the DBMS directly to make the change. Processing the Database 31 insert delete

32. Dr. Chen, Management Information Systems SQL—“see-quell”  International standard language for creating databases and database structures, and processing databases Used by most popular DBMS Following SQL statement inserts a new row into the Student table: INSERT INTO Student ([Student Number], [Student Name], HW1, HW2, MidTerm) VALUES (1000, ’Franklin, Benjamin’, 90, 95, 100); Structured Query Language (SQL) 32

33. Dr. Chen, Management Information Systems DBMS provides tools to assist in administration of the database.DBMS Used to set up a security system involving user accounts, passwords, permissions, and limits for processing the database Backing up database data, adding structures to improve performance of database applications, removing data no longer wanted or needed, and similar tasks Most organizations dedicate one or more employees to the role of database administration (as database administrator – DBA) Administering the Database 33

34. Dr. Chen, Management Information Systems Major Responsibilities of Database Administration 34 Fig 5-10 Summary of Database Administration Tasks

35. Dr. Chen, Management Information Systems Study Questions Q1: What is the purpose of a database? Q2: What is a database? Q3: What are the components of a database application system? Q4: How do database applications make databases more useful? Q5: How are data models used for database development? Q6: How is a data model transformed into a database design? Q7: What is the users’ role in the development of databases? Q8: 2022?

36. Dr. Chen, Management Information Systems Multi-User Processing Problem A database application includes forms, reports, queries, and applications programs available to one or more users. This figure depicts multi-user database processing. The system must be managed properly to avoid the following problems (called concurrent problems): Potential update loss because two users update same data at the same time Potential locking problems Possible data conflicts How to avoid these problems? Fig 5-11 Use of Multiple Database Applications 36

37. Dr. Chen, Management Information Systems Multi-User Processing Problem

38. Dr. Chen, Management Information Systems Lost-update problem  Process A reads a customer record from a file containing account information, including the customer’s account balance and phone number.  Process B now reads the same record from the same file so it has its own copy.  Process A changes the account balance in its copy of the customer record and writes the record back to the file.  Process B—which still has the original stale value for the account balance in its copy of the customer record—updates the customer’s phone number and writes the customer record back to the file.  Process B has now written its stale account balance value to the file, causing the changes made by process A to be lost. (Source: http://en.wikipedia.org/wiki/File_locking) Multi-User Processing Problem (another example) 38

39. Dr. Chen, Management Information Systems What Are Forms, Reports, and Queries? Reports show data in a structured context. Data entry forms are used to read, insert, modify, and delete data. Reports are used to show data in a structured context as the example to the right shows. Fig 5-12 Example of a Student Report 39

40. Dr. Chen, Management Information Systems What Are Forms, Reports, and Queries? Sample query form used to enter phrase for search Sample query results of query operation A query form helps the user quickly find answers to questions. In this case, the words “barriers to entry” were found in Baker’s record. Fig 5-13 (a) & (b) Sample Query and Results 40

41. Dr. Chen, Management Information Systems Forms, reports, and queries work well for standard functions. However, most applications have unique requirements that a simple form, report, or query cannot meet. Application programs process logic that is specific to a given business need. Application programs serve as an intermediary between the Web server and database.  Responds to events, such as when a user presses a submit button; also reads, inserts, modifies, and deletes database data Why Are Database Application Programs Needed? 41

42. Dr. Chen, Management Information Systems Four Database Application Programs Running on a Web Server Computer Fig 5-14 Four Application Programs on a Web Server Computer 42 Database application programs process logic specific to a given business need. For example, a program could track backordered items and hold a customer order until the items are ready to ship. Application programs enable database processing over the Internet as the figure below shows. Users access the applications programs via a Web server, which in turn accesses a single DBMS and database.

43. Dr. Chen, Management Information Systems Enterprise DBMS  Process large organizational and workgroup databases  Support many, possibly thousands, of users and many different database applications  Support 24/7 operations and can manage databases that span dozens of different magnetic disks with hundreds of gigabytes or more of data  IBM’s DB2, Microsoft’s SQL Server, and Oracle’s Oracle are examples of enterprise DBMS products. Personal DBMS  Designed for smaller, simpler database applications  Used for personal or small workgroup applications that involve fewer than 100 users (normally fewer than 15), single user Enterprise DBMS vs. Personal DBMS 43

44. Dr. Chen, Management Information Systems Access: A DBMS and an Application Development Product Before building a database, developers construct a logical representation of database data called a data model to describe the data and relationships to be stored in database. Here’s a comparison of an Enterprise DBMS versus a Personal DBMS.  Enterprise DBMS Large organizational and workgroup databases Hundred to thousands of users Many different database applications 24/7 operations Oracle, DB2, SQL Server  Personal DBMS Smaller, simpler applications Personal or small workgroup applications 1 - 100 users Microsoft Access is both a DBMS and application development product as this figure depicts. 44 Fig 5-15 Personal Database System

45. Dr. Chen, Management Information Systems PART II

46. Dr. Chen, Management Information Systems Study Questions Q1: What is the purpose of a database? Q2: What is a database? Q3: What are the components of a database application system? Q4: How do database applications make databases more useful? Q5: How are data models used for database development? Q6: How is a data model transformed into a database design? Q7: What is the users’ role in the development of databases? Q8: 2022?

47. Dr. Chen, Management Information Systems How to Design a Database? Questions: –What tables to create? (e.g., GU database) –What attributes should be included in each table? –How those tables are related to each other? Data model: is a conceptual representation of data classes (data files) and their relationships. Relational database: data are organized as two-dimensional tables called relations, which are linked together by sharing the same field.

48. Dr. Chen, Management Information Systems Q5: How Are Data Models Used for Database Development? Database Development Process A data model is similar to blueprints for a house. It’s a logical representation of database data that describes data and their relationships. Fig 5-16 Database Development Process 48

49. Dr. Chen, Management Information Systems Steps of Database Development User view-1User view-2User view-3 … User view-N Conceptual Schema (Model) … … Logical Model (ERD or E/ERD) Implementation (w/Physical or Internal Model) User interview & Integrated Model 49

50. Dr. Chen, Management Information Systems How are data models used for database development? Conceptual Design –The process of preparing an abstract model of the database from business perspective, which describes the information needs of end users of the database –Entity-relationship approach => E-R Diagram (ERD) –Relational DBMS: Transform ERD to tables Normalization process (you will learn it later) Physical Design –Describe how data would be physically stored in the data storage –Depends on the DBMS

51. Dr. Chen, Management Information Systems Entity-relationship (E-R) data model  Entity is another term for Table File  A tool for constructing data models  Developers use it to describe the content of a data model by defining entities that will be stored in database and relationships among those entities  Unified Modeling Language (UML), less popular, tool for data modeling Unified Modeling Language (UML) What Is the Entity-Relationship Data Model? 51

52. Dr. Chen, Management Information Systems Some thing that the users want to track Examples of entities:  Order, Customer, Salesperson, and Item. Some entities represent a physical object, such as Item or Salesperson; others represent a logical construct or transaction, such as Order or Contract.  Entity names are always singular. Attributes  Describe characteristics of an entity.  Examples: order attributes are OrderNumber, OrderDate, SubTotal, Tax, Total, and so forth. Identifier (Key)  An attribute (or group of attributes) whose value is associated with one and only one entity instance. Entities (Table or File) 52

53. Dr. Chen, Management Information Systems How are data models used for database development? An entity-relationship (ER) data model helps developers define things (entities) that will be stored in the database as they are building a data model. It also defines relationships among those entities. Entities are things users want to track. It can be a physical object (inventory items) or a logical transaction (sales order). The names are always singular. Each entity has attributes that describe its characteristics. The entity “Order” has attributes like “OrderNumber” and “OrderDate”. An identifier (pk) is an attribute whose value is associated with one and only one entity instance. “OrderNumber” is the identifier for the “Order” entity because there should only be one number for each order. (see next slide)

54. Dr. Chen, Management Information Systems Segment of an Enterprise Data Model A Data Model on Customer and Order CUSTOMERORDER Q1. One CUSTOMER normally places ___ ORDER? Q2. One ORDER normally is placed by __ CUSTOMER? How about the relationship between ORDER and PRODUCT? (see next slide) 1 M

55. Dr. Chen, Management Information Systems Q3. One PRODUCT normally is contained in __ ORDER? ORDER ORDER_NUMBER (pk) Customer_ID Order_Date Q4. One ORDER normally contains __ PRODUCT? M M

56. Dr. Chen, Management Information Systems Q3. One PRODUCT normally is contained in __ ORDER? ORDER ORDER_NUMBER (pk) Customer_ID Order_Date Q4. One ORDER normally contains __ PRODUCT? M M

57. Dr. Chen, Management Information Systems (a) Segment of an Enterprise Data Model Comparison of enterprise and project level data models Q: what are two major differences between (a) & (b)? (b) Segment of a Project-Level Data Model

58. Dr. Chen, Management Information Systems Student Data Model Entities Fig 5-17 Student Data Model Entities Student, Department, Advisor, Email, and Office_Visit are the entity names in this model. The entity identifiers are StudentNumber, DeptName, and AdvisorName. Not all entities require an identifier. 58 pk pk? Email_Number Visit_ID

59. Dr. Chen, Management Information Systems Entities with Relationships Relationships join one entity to another entity –One-to-one – 1:1 –One-to-many – 1:N –Many-to-many – N:M This diagram shows that each Department Entity can have multiple Adviser Entities in a one- to-many relationship. Adviser Entities can have a many-to-many relationship with Student Entities. 59 Fig 5-18 Examples of Department Adviser, and Student Entities and Relationships 1:N M:N or N:M

60. Dr. Chen, Management Information Systems Entity symbols A special entity that is also a relationship Relationship symbols Basic E-R notation Attribute symbols 60 Relationship degrees specify number of entity types involved Relationship cardinalities specify how many of each entity type is allowed

61. Dr. Chen, Management Information Systems Fig 5-19 Sample Relationship (Version 1) Crow ’s Feet 1:NN: M N:M = many-to-many relationships One adviser can have many students and one student can have many advisers. 1:N = one-to-many relationships One department can have many advisers, but an adviser has at most one department. 61

62. Dr. Chen, Management Information Systems Fig 5-20: Sample Relationships (Version 2) Advisers may advise in more than one department, but a student may have only one adviser, representing a policy that students may not have multiple majors. 62 What is the main difference between V1 and V2

63. Dr. Chen, Management Information Systems 5-63 Crow’s-Foot Diagram Version Fig 5-21 Sample Relationships Showing Maximum/Minimum Cardinality Maximum cardinality represents the maximum number of entities that can be involved in a relationship. Minimum cardinality represents the minimum number of entities that can be involved in a relationship. The vertical bar below indicates that at least one entity is required between Department and Adviser and between Adviser and Student. The oval below indicates that an entity is optional and doesn’t require a relationship. 63 mandatory optional

64. Dr. Chen, Management Information Systems Study Questions Q1: What is the purpose of a database? Q2: What is a database? Q3: What are the components of a database application system? Q4: How do database applications make databases more useful? Q5: How are data models used for database development? Q6: How is a data model transformed into a database design? Q7: What is the users’ role in the development of databases? Q8: 2022?

65. Dr. Chen, Management Information Systems Database design is the process of converting a data model into tables, relationships, and data constraints. Database design team transforms entities into tables and expresses relationships by defining foreign keys. Two important database design concepts: normalization and the representation of two kinds of relationships. Normalization is a foundation of database design. Representation of relationships will help you understand important design considerations. Database Design 65

66. Dr. Chen, Management Information Systems How is a data model transformed into a database design? Fig 5-22: Poorly Designed Employee Table Converting a poorly structured table into two or more well-structured tables is called normalization ( Normalization Normalization The table below is poorly designed because it includes the DeptName as part of the Employee record, making it difficult to update. It also creates data integrity problems because the DeptName is not consistent throughout the table after the data were updated. Question: What happen if “Smith” is laid off and the record is deleted? 66

67. Dr. Chen, Management Information Systems Steps of Database Development User view-1User view-2User view-3 … User view-N Conceptual Schema (Model) … … Logical Model (ERD or E/ERD) Implementation (w/Physical Model) ??? 67

68. Dr. Chen, Management Information Systems Steps of Database Development User view-1User view-2User view-3 … User view-N Conceptual Schema (Model) … … Logical Model (ERD or E/ERD) Implementation (w/Physical Model) NORMALIZATION (up to 3NF) (more tables created) User interview & Integrated Model 68

69. Dr. Chen, Management Information Systems In the right figures, some rows show Dept. 100 is “Accounting and Finance” and others show Dept. 100 is “Accounting.” Which one is correct? A table with data integrity problems will produce incorrect results and inconsistent information. Data integrity problems happen when data are duplicated. Users will lose confidence in the information, and system will develop a poor reputation. Information systems with poor reputations become serious burdens to the organizations that use them. Data Integrity Problems 69

70. Dr. Chen, Management Information Systems Normalizing for Data Integrity Normalized tables eliminate data duplication, but they can be slower to process. General goal of normalization is to construct tables such that every table has a single topic or theme so that the database will be more reliable and stable for a long period of time without further changes or redesign.normalization 70

71. Dr. Chen, Management Information Systems Normalizing the tables by splitting the Department data into a separate table, as shown below, allows each table to describe a single topic or theme. The tables have been transformed into a normal form. By eliminating the duplicate data, you eliminate data integrity problems. That’s called normalizing for data integrity. Now, the department name only needs to be updated in one place in the normalized tables. Normalizing for Data Integrity 71 Why it is in a better status? Question: What happen if “Smith” is laid off and the record is deleted? Fig 5-23: Two Normalized Tables

72. Dr. Chen, Management Information Systems Summary of Normalization: Representing Relationships 72 This chart shows the necessary steps to transform a data model into a relational database design. Fig 5-24 Transforming a Data Model into a Database Design will learn more in bmis441 (for MIS concentration)

73. Dr. Chen, Management Information Systems Database practitioners classify tables into various normal forms according to the kinds of problems they have. normal forms Transforming a table into a normal form to remove duplicated data and other problems is called normalizing the table. normalizing Normalization is just one criterion for evaluating database designs. Normalized designs can be slower to process, database designers sometimes choose to accept non-normalized tables. The best design depends on the users’ processing requirements. Summary of Normalization 73

74. Dr. Chen, Management Information Systems Steps for Transforming Data Model Into a Database Design 1.Construct Adviser table and Student tables with key fields (pk) 2.Represent relationships by adding foreign keys (fk) 3.Create new table for N:M relationships (only if the relationship is N:M)

75. Dr. Chen, Management Information Systems Q/A When using the relational model to represent data, one must ________. A) add a foreign key to one of the tables B) have more than ten tables in the model C) establish only N:M relationships between tables D) use metadata instead of foreign keys Answer:

76. Dr. Chen, Management Information Systems Transforming Data Model Into a Database Design – Step 1: Construct Tables with Key fields ‘pk’ The figure on the left represents the relationship (1:N) between tables. The figure on the right shows a normalized table for each entity. Figure 5-25 (a&b) Representing a 1:N Relationship 1. However, we should know that AdvserName is not a good pk as it may not be “unique”. 2. What should be a good one? pk

77. Dr. Chen, Management Information Systems From Figure 5-25 (c) Representing a 1:N Relationship Transforming Data Model Into a Database Design - Step 2: Adding fk pk fk pk

78. Dr. Chen, Management Information Systems 78 Fig 5-25: Representing a 1:N Relationship (in normalized form) 78 pk Step 1. Step 2. add foreign key (fk) fk Transforming a Data Model into a Database Design: 1:N Relationship

79. Dr. Chen, Management Information Systems Figure 5-26 (a&b) Incorrect Representation of N:M Relationship Transforming Data Model Into a Database Design - Step 3: Create new table for N:M relationships The previous relationship is 1:N, therefore, it does not need to create a new table Because it is not in Third Normal Form (3NF). How?

80. Dr. Chen, Management Information Systems AdviserName Email Adviser StudentNumber StudentName MidTerm Student AdviserName Email Adviser StudentNumber StudentName MidTerm Student AdviserName StudentNumber Adviser_Student How to solve the M:N problem? (intersection entity) What is the pk in the new Table (Adviser_Student)? Ans: AdviserName and StudentNumber together (cpk – composite key) General Rule: One M:N relationship will be broken down into Two 1:M relationships.

81. Dr. Chen, Management Information Systems How to solve the M:N problem? pk [1] [2] [3] Finally, three tables are produced for the normalized form. Therefore, two tables originally in the data model and three tables are produced after the normalization.

82. Dr. Chen, Management Information Systems How to solve the M:N problem? The Final Status pk What is the pk? cpk (composite key) [2] [3] [1]

83. Dr. Chen, Management Information Systems Fig 5-26: Representing an N:M Relationship 83 (intersection entity w/ cpk) Steps 1&2. Step 3. pk fk pk

84. Dr. Chen, Management Information Systems Users are the final judges of:  What data the database should contain,  How tables should be related. Users review data model to be sure it accurately reflects users’ view of the business.  Mistakes will come back to haunt you. Easiest time to change database structure is during data modeling stage. Changing a relationship from one-to-many to many-to-many in a data model is simply a matter of changing the 1:N notation to N:M. User review of the data model is crucial. Q7: What Is the Users’ Role in the Development of Databases? 84

85. Dr. Chen, Management Information Systems Users are the final judges of:  What data the database should contain,  How tables should be related. Users review data model to be sure it accurately reflects users’ view of the business.  Mistakes will come back to haunt you. Easiest time to change database structure is during data modeling stage. Changing a relationship from one-to-many to many-to-many in a data model is simply a matter of changing the 1:N notation to N:M. User review of the data model is crucial. Q7: What Is the Users’ Role in the Development of Databases? 85

86. Dr. Chen, Management Information Systems From Data to Knowledge: How Can Organization Gain Competitive Advantage? (Survive and Prosper in the Digital Economy) Data process Information Quality Information Accessible Organizational Knowledge Sharable Collaborative -As a product NOT byproduct -As core intellectual capital NOT merely a few smart employers Decision Making Available Reusable CRM Accounting Finance Operations Manufacturing External customers D. B. D.B.: Structured: R-DBMS Unstructured: Document Mgt. Systems context, experience automateinformateinnovate Useable K.B D.W

87. Dr. Chen, Management Information Systems Q8: 2022? Relational databases will look much different Use of non-relational data stores, called NoSQL will be more common Major DBMS vendors lose out to open-source products and shift focus to services supporting open source software like Bigtable, Dynamo, Cassandra? Database models will be very different

88. Dr. Chen, Management Information Systems VIDEO Video: Software as a Service overview (2m15s)- BMIS235 88

89. Dr. Chen, Management Information Systems End of Chapter 5