Transcript Informational Systems - Carl Rebman Associate Professor of

Chapter 3
Database Management
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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
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Database Management for
Strategic Advantage
Database – a collection of related data
organized in a way to facilitate data
searches
 Use databases to:
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Create a book
Track book sales
Set salaries and wages
Pay employees
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Database Management for
Strategic Advantage
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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
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Database Management for
Strategic Advantage
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Advantages of the Database Approach
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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
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Database Management for
Strategic Advantage
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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
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Key Database Activities
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Entering and Querying Data
– Form
– Structured Query Language (SQL)
– Query by example (QBE)
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Key Database Activities
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Creating Database Reports
– Report – a compilation of data that is organized
and produced in printed format
– Report Generators
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Key Database Activities
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Database Design
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Must be organized
Few or no redundancies
Data model – a map of entity relationships
Keys
• Primary key
• Combination primary key
• Secondary key
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Key Database Activities
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Database Associations
– One-to-one (teams to stadiums)
– One-to-many (player to team)
– Many-to-many (players to games)
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Key Database Activities
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Entity-Relationship Diagramming (ERD)
– Commonly used when designing databases
– One draws entities (tables) as boxes and lines
between entities to show relationships
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Key Database Activities
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The Relational Model of Databases
– Entities linked by a common key field
• Records = rows
• Fields = columns
– Other models exist
• Hierarchical
• Network
• Object-oriented model
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Key Database Activities
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Normalization
– A technique for making complex databases more
efficient and more easily handled by the DBMS
– Eliminates data redundancy
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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
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How Organizations Get the
Most from Their Data
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Linking Web Sites to Databases
– Example: Amazon
• 2.5 million titles
• Managing online data effectively
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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
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How Organizations Get the
Most from Their Data
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Data Mining
– Online Transaction Processing (OLTP)
• Immediate automated responses to user requests
• Multiple concurrent transactions
• A big part of interactive Internet e-commerce
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How Organizations Get the
Most from Their Data
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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
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How Organizations Get the
Most from Their Data
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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
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How Organizations Get the
Most from Their Data
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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
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How Organizations Get the
Most from Their Data
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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
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How Organizations Get the
Most from Their Data
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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
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