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BUSINESS DRIVEN TECHNOLOGY Chapter Seven: Storing Organizational Information - Databases. LEARNING OUTCOMES. 7.1 Define the fundamental concepts of the relational database model 7.2 Evaluate the advantages of the relational database model
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BUSINESS DRIVEN TECHNOLOGY Chapter Seven: Storing Organizational Information - Databases
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
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
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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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
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
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
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 • Potential relational database for Coca-Cola
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
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
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
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
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
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
DATABASE MANAGEMENT SYSTEMS • Database management systems (DBMS) – software through which users and application programs interact with a database
DATABASE MANAGEMENT SYSTEMS • Four components of a DBMS
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
Data Definition Component • The data dictionary essentially defines the logical properties of the information that the database contains
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 • Reportgenerators – users can define report formats • Query-by-example (QBE) – users can graphically design the answers to specific questions • Structured query language (SQL) – query language
Data Manipulation Component • Sample report using Microsoft Access Report Generator
Data Manipulation Component • Sample report using Microsoft Access Query-By-Example (QBE) tool
Data Manipulation Component • Results from the query in Figure 2.11
Data Manipulation Component • SQL version of the QBE Query in Figure 2.11
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
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
INTEGRATING INFORMATION AMONG MULTIPLE DATABASES • Forward integration – takes information entered into a given system and sends it automatically to all downstream systems and processes
INTEGRATING INFORMATION AMONG MULTIPLE DATABASES • Backward integration – takes information entered into a given system and sends it automatically to all upstream systems and processes
INTEGRATING INFORMATION AMONG MULTIPLE DATABASES • Building a central repository specifically for integrated information
OPENING CASE STUDY QUESTIONSSearching for Revenue - Google • Identify the different types of entity classes that might be stored in Google’s indexing database • Explain why database technology is so important to Google’s business model • Explain the difference between logical and physical views and why logical views are important to Google’s employees
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
CHAPTER SEVEN CASE QUESTIONS • Identify the different types of entity classes and attributes potentially maintained in the Hotcourses database • Describe the two different ways that employees at Hotcourses might access the information in their databases • Create two questions that a manager at Hotcourses could turn into queries and run against a database to discover business intelligence