Transcript chapter_07

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)
CHAPTER SEVEN OVERVIEW
RELATIONAL DATABASE FUNDAMENTALS
• There are numerous database models including:
– Hierarchical database – stores related information in
terms of predefined categorical relationships in a “treelike” 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
Coca-Cola Bottling Company of Egypt
• Over 7,400 employees, owns and operate 11
bottling plants, 29 sales and distribution centers
• Implemented an inventory-tracking database
– Improve order accuracy by 27%
– Decrease order response time by 66%
– Increase sales by 20%
• Traditionally, the company sent distribution trucks
to each customer’s premises to take orders and
deliver stock
Coca-Cola Bottling Company of Egypt (2)
• There were many problems associated with such
process:
– Numerous information entry errors, which caused orderfulfillment time to take an average of three days.
• To remedy the situation, Coca-Cola decided
– To create presales teams equipped with hand-held
devices to visit customers and take orders
electronically. On returning to the office, the teams
synchronized orders with the company’s inventorytracking database.
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
Keys and Relationships
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
• e.g. one person could perform a query to determine which
distributors delivered shipments to Pizza Palace last week, while
another person could perform some sort of statistical analysis to
determine the frequency at which Sprite and Diet Coke appear on
the same order.
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
• Some organizations must be able to support hundreds or thousands
of online users including employees, partners, customers and
suppliers, who all want to access and share information.
• Databases today scale to exceptional levels, allowing all types of
users and programs to perform information-processing and
information-searching tasks.
Reduced Information Redundancy
• Databases reduce information redundancy
– Redundancy – the duplication of information or storing the same
information in multiple places
– Redundant information occurs because organizations frequently
capture and store the same information in multiple locations.
• Inconsistency is one of the primary problems with
redundant information
– Which makes it difficult to determine which values are the most current
or most accurate
– Not having correct information is confusing and frustrating for
employees and disruptive to an organization.
• Eliminating information redundancy saves space, makes
performing information updates easier, and improves
information quality.
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 e.g. not allow to create an
order for nonexistent customer, provide a negative mark up
percentage, order zero pounds of raw materials
– 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 e.g. a supplier
might implement a constraint stating that no product returns are
accepted after 15 days past delivery.
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
• Various security features of databases can ensure
that individuals have only certain types of access to
certain type of information
An example: CLEAR
• Database can increase personal security as well as
information security. Since 1995, the Chicago
Police Department (CPD) has relied on a crimefighting system called Citizen and Law
Enforcement Analysis and Reporting (CLEAR).
• CLEAR electronically streamlines the way
detectives enter and access critical information to
help them solve crimes, analyze crime patterns,
and ultimately promote security in a proactive
manner. 650,000 new cases/500,00 new arrests
An example: HOMOLOGATION TIMING
• Ford’s European plant manufactures more than 5,000 vehicles a day
and sells them in over 100 countries worldwide.
• Every component of every model must conform to complex
European standards
– Passenger Safety, Pedestrian and Environmental
• These standards govern each stage of manufacturing process from
design to final production.
• The company needs to obtain many thousands of different
approvals each year to comply with the standards.
• Overlooking just one means the company cannot sell the finished
vehicle, which brings the production line to a standstill and could
potentially cost Ford up to 1 million Euros per day.
• So Homologation Timing System help Ford track and analyze these
standards and then finally help Ford substantially reduce its
compliance risk.
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
– Report generators – users can define report formats along with
the information they want to see
– 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-ByExample (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
e.g. SCM application with menu to enter supplier, order, and order
status
• Data administration component – provides tools for
managing the overall database environment by providing
faculties for backup, recovery, security, and performance
e.g. CPO direct the use of security component, implement policies
and procedures concerning who has an access to different types of
information
• 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
• Integrations are expensive and difficult to build and
maintain.
• Most organizations build only forward integration
e.g. sales through billing, implies that only a
change in the initial system will result in changes in
other systems.
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 QUESTIONS
Searching 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
CHAPTER SEVEN CASE
Hotcourses Increases Revenues by 60 Percent
•
Hotcourses is one of the hottest new ebusinesses 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
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