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Chapter 5 Data
Resource Management
James A. O'Brien, and George Marakas.ManagementInformation Systems with MISource2007, 8thed. Boston, MA: McGraw-Hill, Inc.,2007. ISBN: 13 9780073323091
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Chapter 5 Data Resource ManagementChapter 5 2
Logical Data Elements
data may be logically organized into characters, fields, records,files, and databases
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Chapter 5 Data Resource ManagementChapter 5 3
Logical Data Elements Character
A single alphabetic, numeric, or other symbol Field or data item
Represents an attribute (characteristic or quality)of some entity (object, person, place, event) Example: salary, job title
Record Grouping of all the fields used to describe the attributes of an
entity Example: payroll record with name, SSN, pay rate
File or tableA group of related records
DatabaseAn integrated collection of logically related
data elements
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Chapter 5 Data Resource ManagementChapter 5 4
Electric Utility Database
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Chapter 5 Data Resource ManagementChapter 5 5
Database Structures
Common database structuresHierarchicalNetworkRelationalObject-orientedMulti-dimensional
Database management system (DBMS) packages aredesigned to use a specific data structure to provide endusers with quick, easy access to information stored indatabases.
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Hierarchical Structure
Early DBMS structure
Records arranged in tree-like structure
Relationships are one-to-many
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Network Structure
Used in some mainframe DBMS packagesMany-to-many relationships
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Relational Structure
Most widely used structure
Data elements are stored in tablesRow represents a record; column is a field Can relate data in one file with data in another,
if both files share a common data element
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Relational Operations
SelectCreate a subset of records that meet a stated
criterionExample: employees earning more than
$30,000 Join
Combine two or more tables temporarilyLooks like one big table
ProjectCreate a subset of columns in a table
Three basic operations can be performed on a relational database to
create useful sets of data.
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Multidimensional Structure Variation of relational modelUses multidimensional structures to
organize data and express the relationshipsbetween data
Data elements are viewed as being in cubes You can visualize multidimensional structures as cubes
of data and cubes within cubes of data. Each side of thecube is considered a dimension of the data
Popular for analytical databases that supportOnline Analytical Processing (OLAP) in whichfast answers to complex business queries areexpected.
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Multidimensional Model
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Object-Oriented Structure
Anobjectconsists ofData values describing the attributes of an
entity
Operations that can be performed on the data This encapsulation capability allows the object-
oriented model to handle complex types of data(graphics, pictures, voice, and text) more easily
than other database structures. InheritanceNew objects can be created by replicating
some or all of the characteristics of parent
objects
is considered one of the key technologies of a new generation of
multimedia Web-based applications.
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Object-Oriented Structure
Source: Adapted from Ivar Jacobsen, Maria Ericsson, and Ageneta Jacobsen, The ObjectAdvantage: Business Process Reengineering with Object Technology(New York: ACM Press,1995), p. 65.Copyright @ 1995, Association for Computing Machinery. By permission.
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Chapter 5 Data Resource ManagementChapter 5 14
Object-Oriented Structure
Used in object-oriented database managementsystems (OODBMS)
Supports complex data types more efficiently
than relational databasesExample: graphic images, video clips,
web pages Examples include multimedia object extensions to IBMs
DB2 and Oracles object-based cartridges for Oracle10g.
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Evaluation of Database Structures HierarchicalWorks for structured, routine transactionsCant handle many-to-many relationship
NetworkMore flexible than hierarchicalUnable to handle ad hoc requests
Relational
Easily responds to ad hoc requestsEasier to work with and maintainNot as efficient/quick as hierarchical or network
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The major limitation of the relational model is thatrelational database management systems cannotprocess large amounts of business transactions asquickly and efficiently as those based on the hierarchical
and network models
Chapter 5 Data Resource ManagementChapter 5 16
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Chapter 5 Data Resource ManagementChapter 5 17
Database Development
Database Administrator (DBA) In charge of enterprise database development Improves the integrity and security of
organizational databasesUses Data Definition Language (DDL) to
develop and specify data contents,relationships, and structure
Stores these specifications in a datadictionary or a metadata repository
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Data Dictionary
A data dictionaryContains data about data (metadata)Relies on specialized software component to
manage a database of data definitions It contains information on..The names and descriptions of all types of
data records and their interrelationships
Requirements for end users access and useof application programs
Database maintenanceSecurity
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Database Development
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Data Planning Process
Database development is a top-down processDevelop an enterprise model that defines the
basic business process of the enterprise
Define the information needs of end users ina business process Identify the key data elements that are
needed to perform specific business activities
(entity relationship diagrams)
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Entity Relationship Diagram
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Database Design Process
Data relationships are represented in a data model thatsupports a business process This model is the schemaor subschemaon which to
base The physical design of the database The development of application programs to support
business processes Logical Design
Schema - overall logical view of relationships
Subschema - logical view for specific end usersData models for DBMS
Physical Design How data are to be physically stored and
accessed on storage devices
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Chapter 5 Data Resource ManagementChapter 5 23
Logical and Physical Database Views
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Chapter 5 Data Resource ManagementChapter 5 24
Data Resource Management
Data resource management is a managerial activityUses data management, data warehousing,
and other IS technologiesManages data resources to meet the information
needs of business stakeholders Data stewards
Dedicated to establishing and maintaining thequality of data
Need business, technology, and diplomatic skillsFocus on data content
Judgment is a big part of the job
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Types of Databases
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Operational Databases
Stores detailed data needed to support businessprocesses and operationsAlso called subject area databases(SADB),
transaction databases, and productiondatabasesDatabase examples: customer, human
resource, inventory
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Distributed Databases Distributed databases are copies or parts of databases stored on
servers at multiple locations Improves database performance at worksites
Advantages Protection of valuable data Data can be distributed into smaller databases
Each location has control of its local data All locations can access any data, any where
Disadvantages Maintaining data accuracy
Replication Look at each distributed database and find changes
Apply changes to each distributed database Very complex
Duplication One database is master Duplicate the master after hours, in all locations
Easier to accomplish
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External Databases
Databases available for a fee from commercialonline services, or free from the WebExample: hypermedia databases, statistical
databases, bibliographic and full textdatabasesSearch engines like Google or Yahoo are
external databases
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Hypermedia Databases
A hypermedia database containsHyperlinked pages of multimedia Interrelated hypermedia page elements,
rather than interrelated data records
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Components of Web-Based
System
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Data Warehouses
Stores static data that has been extracted fromother databases in an organizationCentral source of data that has been cleaned,
transformed, and catalogedData is used for data mining, analytical
processing, analysis, research, decision support Data warehouses may be divided into data martsSubsets of data that focus on specific aspects
of a company (department or business process)
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Data Warehouse Components
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Applications and Data Marts
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Data Mining
Data in data warehouses are analyzed to revealhidden patterns and trendsMarket-basket analysis to identify new
product bundlesFind root cause of qualify or manufacturing
problemsPrevent customer attrition
Acquire new customersCross-sell to existing customersProfile customers with more accuracy
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Traditional File Processing
Data are organized, stored, and processed inindependent filesEach business application designed to use
specialized data files containing specifictypes of data records
ProblemsData redundancy
Lack of data integrationData dependence (files, storage devices,software)
Lack of data integrity or standardization
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Traditional File Processing
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Database Management
Approach The foundation of modern methods of managing
organizational dataConsolidates data records formerly in
separate files into databasesData can be accessed by many different
application programs
A database management system (DBMS) isthe software interface between users anddatabases
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Database Management
Approach
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Chapter 5 Data Resource ManagementChapter 5 39
Database Management System
In mainframe and server computer systems, asoftware package that is used toCreatenew databases and database
applicationsMaintainthe quality of the data in an
organizations databasesUsethe databases of an organization to
provide the information needed by end users
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Common DBMS Software
Components Database definitionLanguage and graphical tools to define
entities, relationships, integrity constraints,and authorization rights
Nonprocedural accessLanguage and graphical tools to access data
without complicated coding Application developmentGraphical tools to develop menus, data entry
forms, and reports
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Common DBMS Software
Components Procedural language interfaceLanguage that combines nonprocedural access
with full capabilities of a programming language Transaction processingControl mechanism prevents interference from
simultaneous users and recovers lost data after
a failure
Database tuningTools to monitor, improve database performance
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Chapter 5 Data Resource ManagementChapter 5 42
Database Management System
Database DevelopmentDefining and organizing the content,
relationships, and structure of the data neededto build a database
Database Application DevelopmentUsing DBMS to create prototypes of queries,
forms, reports, Web pages
Database MaintenanceUsing transaction processing systems and
other tools to add, delete, update, and correctdata
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DBMS Major Functions
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Database Interrogation
End users use a DBMS query feature or reportgenerator
Response is video display or printed report
No programming is required Query language
Immediate response to ad hoc data requests
Report generatorQuickly specify a format for information you
want to present as a report
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Database Interrogation
SQL QueriesStructured, international standard query
language found in many DBMS packages
Query form is SELECTFROMWHERE
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Database Interrogation
Boolean LogicDeveloped by George Boole in the mid-1800sUsed to refine searches to specific
informationHas three logical operators: AND, OR, NOT
ExampleCats OR felines AND NOT dogs OR
Broadway
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Database Interrogation
Graphical and Natural Queries It is difficult to correctly phrase SQL and other
database language search queries
Most DBMS packages offer easier-to-use,point-and-click methodsTranslates queries into SQL commandsNatural language query statements are similar
to conversational English
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Graphical Query Wizard
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Database Maintenance
Accomplished by transaction processingsystems and other applications, with the supportof the DBMS
Done to reflect new business transactions andother eventsUpdating and correcting data, such as
customer addresses
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Application Development
Use DBMS software development tools todevelop custom application programsNot necessary to develop detailed data-
handling procedures using conventionalprogramming languagesCan include data manipulation language
(DML) statements that call on the DBMS to
perform necessary data handling