6' Databases and Information Management

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Chapter 6 Roadmap
1. ORGANIZING DATA IN A TRADITIONAL FILE
ENVIRNOMENT File Organization Concepts Problems
with the Traditional File Environment 2. THE
DATABASE APPROACH TO DATA MANAGEMENT Database
Management Systems Capabilities of Database
Management Systems Designing Databases 3. USING
DATABASES TO IMPROVE BUSINESS PERFORMANCE AND
DECISION MAKING Data Warehouses Business
Intelligence, Multidimensional Data Analysis, and
Data Mining Databases and the Web 4. MANAGING
DATA RESOURCES Establishing an Information
Policy Ensuring Data Quality
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MANAGEMENT CHALLENGES

• Organizational obstacles to a database
  environment
• Challenges existing power structure, requires
  organizational restructure
• Integrating data and ensuring quality
• Legacy data, enterprise-wide systems
• Cost/Benefit Considerations
• Large initial costs, delayed benefits

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ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT
File Organization Terms and Concepts

• Database Group of related files
• Entity Person, place, thing, event about which
  information is maintained
• Attribute Description of a particular entity
• Key field Identifier field used to retrieve,
  update, sort a record

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Problems with the Traditional File Environment

• Data redundancy
• Program-Data dependence
• Lack of flexibility
• Poor security
• Lack of data-sharing and availability

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Database Management System (DBMS)
THE DATABASE APPROACH TO DATA MANAGEMENT

• Software for creating and maintaining databases
• Permits firms to rationally manage data for the
  entire firm
• Acts as interface between application programs
  and physical data files
• Separates logical and design views of data
• Solves many problems of the traditional data file
  approach

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THE DATABASE APPROACH TO DATA MANAGEMENT
Components of DBMS

• Data definition language Specifies content and
  structure of database and defines each data
  element
• Data manipulation language
• Manipulates data in a database
• Data dictionary Stores definitions of data
  elements, and data characteristics

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THE DATABASE APPROACH TO DATA MANAGEMENT
Types of Databases

• Relational DBMS
• Hierarchical and Network DBMS
• Object-Oriented Databases
• Each handles relationships differently.

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TYPES OF RELATIONSHIPS
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THE DATABASE APPROACH TO DATA MANAGEMENT
Relational DBMS

• Represents data as two-dimensional tables called
  relations
• Relates data across tables based on common data
  element
• Examples DB2, Oracle, MS SQL Server

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Hierarchical and Network DBMS

• Hierarchical DBMS
• Organizes data in a tree-like structure
• Supports one-to-many parent-child relationships
• Prevalent in large legacy systems

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Hierarchical and Network DBMS

• Network DBMS
• Depicts data logically as many-to-many
  relationships

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Hierarchical and Network DBMS

• Disadvantages
• Outdated
• Less flexible compared to RDBMS
• Lack support for ad-hoc and English language-like
  queries

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Object-Oriented Databases

• Object-oriented DBMS
• Stores data and procedures as objects that can be
  retrieved and shared automatically
• Handles graphics (CAD), multimedia and Java
• Object-relational DBMS
• Provides capabilities of both object-oriented and
  relational DBMS
• Faster processing than OODBMS by themselves

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CREATING A DATABASECONCEPTUAL DESIGN

• ABSTRACT MODEL, BUSINESS PERSPECTIVE
• HOW WILL DATA BE GROUPED?
• RELATIONSHIPS AMONG ELEMENTS
• ESTABLISH END-USER NEEDS

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CREATING A DATABASEPHYSICAL DESIGN

• DETAILED MODEL BY DATABASE SPECIALISTS
• ENTITY-RELATIONSHIP DIAGRAM
• NORMALIZATION
• HARDWARE / SOFTWARE SPECIFIC

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Designing Databases

• Entity-relationship diagram Methodology for
  documenting databases illustrating relationships
  between database entities
• Normalization Process of creating small stable
  data structures from complex groups of data

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Distributing Databases

• Centralized database
• Used by single central processor or multiple
  processors in client/server network
• There are advantages and disadvantages to having
  all corporate data in one location.
• Security is higher in central environments, risks
  lower.
• If data demands are highly decentralized, then a
  decentralized design is less costly, and more
  flexible.

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Distributing Databases

• Distributed database
• Stored in more than one physical location
• Partitioned database
• Duplicated database
• Regardless of which method is chosen, data
  administrators and business managers need to
  understand how the data in different databases
  will be coordinated and how business processes
  might be effected by the decentralization.

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DATABASE TRENDS

• Multidimensional Data Analysis
• On-line analytical processing (OLAP)
• Multidimensional data analysis
• Supports manipulation and analysis of large
  volumes of data from multiple dimensions/perspecti
  ves

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Data Warehousing and Datamining

• Data warehouse
• Supports reporting and query tools
• Stores current and historical data
• Consolidates data for management analysis and
  decision making

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Data Warehousing and Datamining

• Data mart
• Subset of data warehouse
• Contains summarized or highly focused portion of
  data for a specified function or group of users

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Data Warehousing and Datamining

• Datamining
• Tools for analyzing large pools of data
• Find hidden patterns and infer rules to predict
  trends

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Benefits of Data Warehouses

• Improved and easy accessibility to information
• Ability to model and remodel the data
• Helpful with DSS and ESS

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Databases and the Web

• Database server
• Computer in a client/server environment runs a
  DBMS to process SQL statements and perform
  database management tasks
• Application server
• Software handling all application operations

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MANAGEMENT OPPORTUNITIES, CHALLENGES, AND
SOLUTIONS
Management Opportunities
Business firms have exceptional opportunities to
exploit modern relational database technologies
to improve decision making, and to increase the
efficiency of their business processes.
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MANAGEMENT OPPORTUNITIES, CHALLENGES, AND
SOLUTIONS
Management Challenges

• Organizational obstacles to a database
  environment Need for cooperation in developing
  corporate-wide data administration
• Cost/benefit considerations
• Bringing about significant change in the
  database environment of a firm can be very
  expensive and time consuming.

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MANAGEMENT OPPORTUNITIES, CHALLENGES, AND
SOLUTIONS
Solution Guidelines
The critical elements for creating a database
environment are

• Data administration
• Data-planning and modeling methodology
• Database technology and management
• Users

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Querying Databases Elements of SQL

• Basic SQL Commands
• SELECT Specifies columns (field)
• FROM Identifies tables or views
• WHERE Specifies conditions

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So What?

• Managers need to evaluate DBMS needs,
  capabilities, software packages
• Data model should reflect business processes and
  decision making requirements
• Use the appropriate technology to fit the task,
  hardware, and operating systems