fundamentals of information systems, fifth edition chapter 3 database systems and business...
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Fundamentals of Information Systems, Fifth Edition
Chapter 3 Database Systems and Business
Intelligence
Fundamentals of Information Systems, Fifth Edition 2
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
Fundamentals of Information Systems, Fifth Edition 3
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
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)
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)
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?
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)
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
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)
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
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
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
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