Download chapter3 - Blog Paul Sidarta

Chapter 3
Database Management
Information Systems Today
Leonard Jessup and Joseph Valacich
© 2003 Prentice Hall, Inc.
3-1
© 2003 Prentice Hall, Inc.
3-2
Chapter 3 Objectives
Understand why databases are important to
modern organizations
 Understand how databases work
 Understand how organizations can
maximize their strategic potential with
databases

© 2003 Prentice Hall, Inc.
3-3
Database Management for
Strategic Advantage
Database – a collection of related data
organized in a way to facilitate data
searches
 Use databases to:

Create a book
 Track book sales
 Set salaries and wages
 Pay employees

© 2003 Prentice Hall, Inc.
3-4
Database Management for
Strategic Advantage

The Database Approach: Foundational
Concepts
DBMS – Database Management Systems
 Use a DBMS software to create, store,
organize, and retrieve data from a single
database or several databases
 Example: Microsoft Access

© 2003 Prentice Hall, Inc.
3-5
Database Management for
Strategic Advantage

Advantages of the Database Approach









Program-data independence
Minimal data redundancy
Improved data consistency
Improved data sharing
Increased productivity of application development
Enforcement of standards
Improved data quality
Improved data accessibility
Reduced program maintenance
© 2003 Prentice Hall, Inc.
3-6
Database Management for
Strategic Advantage

Effective Management of Databases

The database administrator (DBA) :
 Works with programmers and analysts to
design and implement the database
 Works with users and managers to establish
database policies
 Implements security features and establishes
database permissions
© 2003 Prentice Hall, Inc.
3-7
Key Database Activities

Entering and Querying Data
Form
 Structured Query Language (SQL)
 Query by example (QBE)

© 2003 Prentice Hall, Inc.
3-8
Key Database Activities

Creating Database Reports
Report – a compilation of data that is organized
and produced in printed format
 Report Generators

© 2003 Prentice Hall, Inc.
3-9
Key Database Activities

Database Design
Must be organized
 Few or no redundancies
 Data model – a map of entity relationships
 Keys




Primary key
Combination primary key
Secondary key
© 2003 Prentice Hall, Inc.
3-10
© 2003 Prentice Hall, Inc.
3-11
Key Database Activities

Database Associations
One-to-one (teams to stadiums)
 One-to-many (player to team)
 Many-to-many (players to games)

© 2003 Prentice Hall, Inc.
3-12
Key Database Activities

Entity-Relationship Diagramming (ERD)
Commonly used when designing databases
 One draws entities (tables) as boxes and lines
between entities to show relationships

© 2003 Prentice Hall, Inc.
3-13
Key Database Activities

The Relational Model of Databases
Entities linked by a common key field
 Records = rows
 Fields = columns
 Other models exist




Hierarchical
Network
Object-oriented model
© 2003 Prentice Hall, Inc.
3-14
Key Database Activities

Normalization
A technique for making complex databases
more efficient and more easily handled by the
DBMS
 Eliminates data redundancy

© 2003 Prentice Hall, Inc.
3-15
© 2003 Prentice Hall, Inc.
3-16
© 2003 Prentice Hall, Inc.
3-17
Key Database Activities

Data Dictionary

A document that explains each piece of
information in the database




Field name
Data type
• Numeric, text, date/time
• Useful for sorting and allocating storage
Is this field a key field?
Business rules
• Update authority
• Valid data values
© 2003 Prentice Hall, Inc.
3-18
How Organizations Get the
Most from Their Data

Linking Web Sites to Databases

Example: Amazon
 2.5 million titles
 Managing online data effectively
© 2003 Prentice Hall, Inc.
3-19
How Organizations Get the
Most from Their Data

Data Mining
A method for better understanding data
 Information on customers, products, markets, etc.
 Drill down: from summary to more detailed data
 Sort and extract information
 Trends, correlations, forecasting, statistics

© 2003 Prentice Hall, Inc.
3-20
How Organizations Get the
Most from Their Data

Data Mining

Online Transaction Processing (OLTP)
 Immediate automated responses to user
requests
 Multiple concurrent transactions
 A big part of interactive Internet e-commerce
© 2003 Prentice Hall, Inc.
3-21
How Organizations Get the
Most from Their Data

Data Mining

Online Analytical Processing (OLAP)
 Graphical software tools that provide complex
analysis of data stored in a database
 Drills down to deeper levels of consolidation
 Time series and trend analysis
 “What if” and “why” questions
© 2003 Prentice Hall, Inc.
3-22
How Organizations Get the
Most from Their Data

Data Mining

Merging Transaction and Analytical Processing
 Real-time OLAP diminishes performance
because the database must be “locked” during
execution time
 Solution: replicate transactions on a 2nd
database server
© 2003 Prentice Hall, Inc.
3-23
How Organizations Get the
Most from Their Data

Data Mining

Merging Transaction and Analytical Processing
 Operational Systems
• Interact with customers and run a business
in real time
• Examples: Order processing, reservation
systems
 Informational Systems
• Support decision making based on stable
point-in-time or historical data
© 2003 Prentice Hall, Inc.
3-24
How Organizations Get the
Most from Their Data

Data Warehousing
Integrating multiple large databases into a
single repository
 Queries, analysis, and processing
 Purpose: put key business information into
the hands of decision makers
 Cost: millions

© 2003 Prentice Hall, Inc.
3-25
How Organizations Get the
Most from Their Data

Data Marts
Instead of one large data warehouse, many
organizations create multiple data marts
 Each contains a subset of the data
 Example: finance, inventory, personnel
 Each data mart is customized for particular
DSS applications
 Cost: typically less than $1 million

© 2003 Prentice Hall, Inc.
3-26