Transcript Chapter 3

Fundamentals of Information
Systems, Fifth Edition
Chapter 3
Database Systems and Business
Intelligence
Principles and Learning Objectives
• Data management and modeling are key aspects
of organizing data and information
– Define general data management concepts and
terms, highlighting the advantages of the database
approach to data management
– Describe the relational database model and outline
its basic features
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Principles and Learning Objectives
(continued)
• A well-designed and well-managed database is an
extremely valuable tool in supporting decision
making
– Identify the common functions performed by all
database management systems, and identify
popular database management systems
• The number and types of database applications will
continue to evolve and yield real business benefits
– Identify and briefly discuss current database
applications
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Data Management
• Without data and the ability to process it an
organization could not successfully complete most
business activities
• For data to be transformed into useful information,
it must first be organized in a meaningful way
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The Hierarchy of Data
• Bit
– Circuit that is either on or off
– Eight bits = one byte
• Character
– Basic building block of information
• Field
– Name, number, or combination of characters that
describes an aspect of a business object or activity
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The Hierarchy of Data (continued)
• Record
– Collection of related data fields
• File
– Collection of related records
• Database
– Collection of integrated and related files
• Hierarchy of data
– Bits, characters, fields, records, files, and databases
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The Hierarchy of Data (continued)
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Data Entities, Attributes, and Keys
• Entity
– Generalized class of people, places, or things for
which data is collected, stored, and maintained
• Attribute
– Characteristic of an entity
• Data item
– Value of an attribute
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Data Entities, Attributes, and Keys
(continued)
• Key
– Field or set of fields in a record that is used to
identify the record
• Primary key
– Field or set of fields that uniquely identifies the
record
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Data Entities, Attributes, and Keys
(continued)
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The Database Approach
• Traditional approach to database management
– Separate data files are created and stored for each
application program
• Database approach to database management
– Multiple application programs share a pool of related
data
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The Database Approach (continued)
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The Database Approach (continued)
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Data Modeling and Database
Characteristics
• When building a database, consider:
– Content: What data should be collected, at what
cost?
– Access: What data should be provided to which
users and when?
– Logical structure: How should data be arranged to
make sense to a given user?
– Physical organization: Where should data be
physically located?
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Data Modeling
• Building a database requires two types of designs
– Logical design
• Abstract model of how data should be structured and
arranged to meet an organization’s information needs
– Physical design
• Fine-tunes the logical database design for
performance and cost considerations
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Data Modeling (continued)
• Planned data redundancy
– Improves system performance
• Data model
– Diagram of data entities and their relationships
• Enterprise data modeling
– Data modeling done at the level of the entire
enterprise
• Entity-relationship (ER) diagrams
– Data models that use basic graphical symbols to
show the organization of and relationships between
data
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Data Modeling (continued)
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The Relational Database Model
• Relational model
– Describes data using a standard tabular format
– Data elements are placed in two-dimensional tables,
called relations, the logical equivalent of files
• Domain
– Allowable values for data attributes
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The Relational Database Model
(continued)
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Manipulating Data
• Selecting
– Eliminates rows according to criteria
• Projecting
– Eliminates columns in a table
• Joining
– Combines two or more tables
• Linking
– Combines two or more tables using common data
attributes
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Manipulating Data (continued)
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Manipulating Data (continued)
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Database Management Systems
(DBMS)
• Group of programs used as an interface between a
database and application programs or a database
and the user
• Used to manage all kinds of data for all kinds of
purposes
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Overview of Database Types
• Flat file
– Simple database program whose records have no
relationship to one another
• Single user
– Only one person can use the database at a time
• Multiple user
– Allows dozens or hundreds of people to access the
same database system at the same time
– Examples: Oracle, Sybase, and IBM
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Providing a User View
• Schema
– Logical and physical structure of the data and
relationships among the data in the database
– Can be part of the database or a separate schema
file
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Creating and Modifying the Database
• Data definition language (DDL)
– Collection of instructions/commands that define and
describe data and data relationships in a database
– Allows database creator to describe the data and the
data relationships that are to be contained in the
schema
• Data dictionary
– Detailed description of all the data used in the
database
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Creating and Modifying the Database
(continued)
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Creating and Modifying the Database
(continued)
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Storing and Retrieving Data
• One function of a DBMS is:
– To be an interface between an application program
and the database
• Concurrency control
– Method of dealing with a situation in which two or
more people need to access the same record in a
database at the same time
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Storing and Retrieving Data
(continued)
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Manipulating Data and Generating
Reports
• Query-by-example (QBE)
– Visual approach to developing database queries or
requests
• Data manipulation language (DML)
– Commands that manipulate the data in a database
• Structured Query Language (SQL)
– Standardized data manipulation language
– Lets programmers learn one powerful query
language and use it on systems ranging from PCs to
the largest mainframe computers
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Manipulating Data and Generating
Reports (continued)
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Database Administration
• Database administrator (DBA) should:
– Have a clear understanding of the fundamental
business of the organization
– Be proficient in the use of selected database
management systems
– Stay abreast of emerging technologies and new
design approaches
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Popular Database Management
Systems
• Popular DBMSs for end users
– Microsoft Access and FileMaker Pro
• Emerging software
– Database as a Service (DaaS) or Database 2.0
– Database administration is provided by the service
provider
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Special-Purpose Database Systems
• Specialized database packages
– Israeli Holocaust Database
– Morphbank
– iTunes Store music and video catalog
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Selecting a Database Management
System
• Important characteristics of databases:
–
–
–
–
–
–
Database size
Database cost
Concurrent users
Performance
Integration
Vendor
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Using Databases with Other Software
• Database management systems are often used
with other software packages or the Internet
• Front-end application
– Directly interacts with users
• Back-end application
– Interacts with applications
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Database Applications
• Manipulate content of a database to produce useful
information
• Common manipulations
– Searching, filtering, synthesizing, and assimilating
data
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Linking Databases to the Internet
• Semantic Web
– Developing a seamless integration of traditional
databases with the Internet
– Allows people to access and manipulate a number of
traditional databases at the same time through the
Internet
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Data Warehouses, Data Marts, and
Data Mining
• Data warehouse
– Holds business information from many sources in
the enterprise
• Data mart
– Subset of a data warehouse
• Data mining
– Information-analysis tool for discovering patterns
and relationships in a data warehouse
– Predictive analysis: Combines historical data with
assumptions about future conditions
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Data Warehouses, Data Marts, and
Data Mining (continued)
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Data Warehouses, Data Marts, and
Data Mining (continued)
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Business Intelligence
• Gathering the right information in a timely manner
and usable form and analyzing it to have a positive
impact on business
• Competitive intelligence
– Limited to information about competitors and the
ways that knowledge affects strategy, tactics, and
operations
• Counterintelligence
– Steps an organization takes to protect information
sought by “hostile” intelligence gatherers
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Distributed Databases
• Data may be spread across several smaller
databases connected via telecommunications
devices
• Give corporations and other organizations more
flexibility in how databases are organized and used
• Replicated database
– Holds a duplicate set of frequently used data
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Distributed Databases (continued)
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Online Analytical Processing (OLAP)
• Software that allows users to explore data from a
number of perspectives
• Provides top-down, query-driven data analysis
• Requires repetitive testing of user originated
theories
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Online Analytical Processing (OLAP)
(continued)
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Object-Relational Database
Management Systems
• Object-oriented database
– Database that stores both data and its processing
instructions
• Object-oriented database management system
(OODBMS)
– Programs that manipulate an object-oriented
database and provide a user interface and
connections to other application programs
• Object-relational database management system
(ORDBMS)
– Capable of manipulating audio, video, and graphical
data
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Visual, Audio, and Other Database
Systems
• Virtual database systems
– Allow different databases to work together as a
unified database system
• Spatial data technology
– Use of a database to store and access data
according to the locations it describes
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Summary
• Data
– Organized into a hierarchy that builds from the
smallest element to the largest
• Traditional file-oriented applications
– Often characterized by program-data dependence
• Data model
– Map or diagram of entities and their relationships
• DBMS
– Group of programs used as an interface between a
database and its users and other applications
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Summary (continued)
• After a DBMS has been installed
– It can be accessed, modified, and queried via a data
manipulation language
• Data warehouse
– Relational database management systems
specifically designed to support management
decision making
• Business intelligence
– Getting enough of the right information in a timely
manner and usable form
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