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BUSINESS DRIVEN TECHNOLOGY

Chapter Seven: Storing Organizational

Information - Databases

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LEARNING OUTCOMES

7.1 Define the fundamental concepts of the relational database model

7.2 Evaluate the advantages of the relational database model

7.3 Compare operational integrity constraints and business-critical integrity constraints

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LEARNING OUTCOMES

7.4 Describe the role and purpose of a database management system

7.5 List and describe the four components of a database management system

7.6 Describe the two primary methods for integrating information across multiple databases

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CHAPTER SEVEN OVERVIEW

• Information is everywhere in an organization

• Information is stored in databases– Database – maintains information about various types

of objects (inventory), events (transactions), people (employees), and places (warehouses)

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CHAPTER SEVEN OVERVIEW

Start

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RELATIONAL DATABASE FUNDAMENTALS

• There are numerous database models including:– Hierarchical database – stores related information in

terms of predefined categorical relationships in a “tree-like” fashion

– Network database – used by a network installation tool to allocate and track network resources

– Relational database model – stores information in the form of logically related two-dimensional tables

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Entities, Entity Classes, and Attributes

• Entity – a person, place, thing, transaction, or event about which information is stored– The rows in each table contain the entities– Figure 2.6 on page 63, CUSTOMER includes Dave’s

Sub Shop and Pizza Palace entities

• Entity class (table) – a collection of similar entities– Figure 2.6 on page 63 includes CUSTOMER, ORDER,

ORDER LINE, DISTRIBUTOR, and PRODUCT entity classes

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Entities, Entity Classes, and Attributes

• Attributes (fields, columns) – characteristics or properties of an entity class– The columns in each table contain the attributes– Figure 2.6 on page 63, attributes for CUSTOMER

include Customer ID, Customer Name, Contact Name, and Phone

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Keys and Relationships

• Primary keys and foreign keys identify the various entity classes (tables) in the database– Primary key – a field (or group of fields) that uniquely

identifies a given entity in a table– Foreign key – a primary key of one table that appears

an attribute in another table and acts to provide a logical relationship among the two tables

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Keys and Relationships

Start

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Keys and Relationships• Potential relational database for Coca-Cola

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RELATIONAL DATABASE ADVANTAGES

• Database advantages from a business perspective include– Increased flexibility– Increased scalability and performance– Reduced information redundancy– Increased information integrity (quality)– Increased information security

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Increased Flexibility

• A well-designed database should:– Handle changes quickly and easily– Provide users with different views– A database has only one physical view

• Physical view – deals with the physical storage of information on a storage device such as a hard disk

– A database can have multiple logical views• Logical view – focuses on how users logically access

information to meet particular business needs

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Increased Scalability and Performance

• A database must scale to meet increased demand, while maintaining acceptable performance levels– Scalability – refers to how well a system can adapt to

increased demands– Performance – measures how quickly a system

performs a certain process or transaction

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Reduced Information Redundancy

• Databases reduce information redundancy– Redundancy – the duplication of information or storing

the same information in multiple places

• Inconsistency is one of the primary problems with redundant information

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Increase Information Integrity (Quality)

• Information integrity – a measure of the quality of information

• Integrity constraints – rules that help ensure the quality of information– Operational integrity constraints – rules that enforce

basic and fundamental information-based constraints– Business-critical integrity constraints – rules that

enforce business rules vital to an organization’s success and often require more insight and knowledge than operational integrity constraints

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Increased Information Security

• Information is an organizational asset and must be protected

• Databases offer several security features including:– Passwords – provide authentication of the user– Access levels – determine who has access to the

different types of information – Access controls – Determine types of user access, such

as read-only access

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DATABASE MANAGEMENT SYSTEMS

• Database management systems (DBMS) – software through which users and application programs interact with a database

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DATABASE MANAGEMENT SYSTEMS

• Four components of a DBMS

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Data Definition Component

• Data definition component – helps create and maintain the data dictionary and the structure of the database

• The data definition component includes the data dictionary– Data dictionary – a file that stores definitions of

information types, identifies the primary and foreign keys, and maintains the relationships among the tables

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Data Definition Component

• The data dictionary essentially defines the logical properties of the information that the database contains

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Data Manipulation Component

• Data manipulation component – allows users to create, read, update, and delete information in a database

• A DBMS contains several data manipulation tools:– Views – Allows users to see, change, sort, and query the

database content– Report generators – users can define report formats – Query-by-example (QBE) – users can graphically design the

answers to specific questions– Structured query language (SQL) – query language

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Data Manipulation Component

• Sample report using Microsoft Access Report Generator

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Data Manipulation Component

• Sample report using Microsoft Access Query-By-Example (QBE) tool

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Data Manipulation Component

• Results from the query in Figure 2.11

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Data Manipulation Component

• SQL version of the QBE Query in Figure 2.11

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Application Generation and Data Administration Components

• Application generation component – includes tools for creating visually appealing and easy-to-use applications

• Data administration component – provides tools for managing the overall database environment by providing faculties for backup, recovery, security, and performance

• IT specialists primarily use these components

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INTEGRATING INFORMATION AMONG MULTIPLE DATABASES

• Organizations typically maintain multiple systems, each with its own database

• Integration – allows separate systems to communicate directly with each other

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INTEGRATING INFORMATION AMONG MULTIPLE DATABASES

• Forward integration – takes information entered into a given system and sends it automatically to all downstream systems and processes

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INTEGRATING INFORMATION AMONG MULTIPLE DATABASES

• Backward integration – takes information entered into a given system and sends it automatically to all upstream systems and processes

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INTEGRATING INFORMATION AMONG MULTIPLE DATABASES

• Building a central repository specifically for integrated information

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OPENING CASE STUDY QUESTIONSSearching for Revenue - Google

1. Identify the different types of entity classes that might be stored in Google’s indexing database

2. Explain why database technology is so important to Google’s business model

3. Explain the difference between logical and physical views and why logical views are important to Google’s employees

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CHAPTER SEVEN CASE Hotcourses Increases Revenues by 60 Percent

• Hotcourses is one of the hottest new e-businesses in London

• Offers a comprehensive online educational marketplace

• After two years of operation the company estimates revenues for 2003 between $100 and $500 million

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CHAPTER SEVEN CASE QUESTIONS

1. Identify the different types of entity classes and attributes potentially maintained in the Hotcourses database

2. Describe the two different ways that employees at Hotcourses might access the information in their databases

3. Create two questions that a manager at Hotcourses could turn into queries and run against a database to discover business intelligence