Transcript Chapter 7

Lead Black Slide
Chapter 7
Information System
Data Management
© 2001 Business & Information Systems 2/e
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Our Agenda
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File Processing
Database Processing
Database Organization
Common Database Software
Using Database Software
Database Use in Information Systems
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Our Agenda (cont’d.)
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Data Warehouses
Multidimensional Databases
Database Administration
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Learning Objectives
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List advantages and disadvantages of
file processing.
Explain what a database is and what a
database management system does.
List advantages and disadvantages of
database processing.
Identify the main types of relationships
in database processing.
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Learning Objectives (cont’d.)
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Explain the organization of relational
databases.
Describe the differences between
database software for personal
computers, multiple-user computers
and networked computers.
Describe several ways of using
database software.
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Learning Objectives (cont’d.)
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Describe the use of databases in
different types of information systems.
Explain what a data warehouse is and
what is meant by data mining.
Describe multidimensional databases
and explain on-line analytical
processing.
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File Processing
Information System
Data Management
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File Processing
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Files consist of related records.
Records consist of related fields.
Fields consist of related characters.
Files must contain a key field – a field
where each record’s occurrence is
unique.
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File Organization
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A file can be organized in secondary
storage as a:
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Sequential file – records are organized one
after the other and each record must be
scanned to until the desired record is
located.
Direct or Random file – records are not
necessarily stored in sequence and can be
accessed directly.
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File Organization (cont’d.)
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A file can be organized in secondary
storage as a:
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Indexed file – records are stored in one file
and the organization of those records is
stored in a second file. To use an indexed
file both files, the data file and the index
file, must be used together.
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File Management
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Managing data files requires that the
data be kept up to date. To do so
requires:
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Modifying, or updating, records involves
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Adding records
Deleting records
Changing records
Data Validation – ensuring the data is
accurate and secure.
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Advantages and Disadvantages
of File Processing
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Advantages
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Simple to use.
Disadvantages
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Processing data in more than one related
file.
Difficult to access data from more than one
file at a time.
Dependency between programs and data.
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Database Processing
Information System
Data Management
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Database Processing
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To overcome some of the disadvantages
of file processing, database processing is
used instead.
The database software is called a
DataBase Management System (DBMS).
A database is a collection of data and
relationships between data stored in
secondary storage.
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Advantages and Disadvantages
of Database Processing
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Advantages
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Duplication of data is reduced.
Easier to process different groups of data.
Not dependent on the organization of data
in the database.
Disadvantages
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Expensive.
More vulnerable than file processing.
Can be complex to develop.
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Database Organization
Information System
Data Management
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Data Relationships
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One-to-one relationship
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One-to-many relationship
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One group of data is related on only one
other group of data.
One group of data is related to one or
more other groups of data.
Many-to-many relationship
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One or more groups of data is related to
one or more other groups of data.
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Types of Databases
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Hierarchical database
Network database
Relational database
Object-oriented database
Object-relational database
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Common Database Software
Information System
Data Management
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Common Database Software
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Personal Computer
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dBASE
Access
FoxPro
Approach
Fourth Dimension
Oracle
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Networked Systems
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© 2001 Business & Information Systems 2/e
Oracle
Sybase
SQL Server
Informix
GemStone
ObjectStore
Versant ODBMS
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Using Database Software
Information System
Data Management
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Using Database Software
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Query languages – allows a user to
query a database.
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SQL is a widely used query language.
Query-By-Example (QBE) – is a
graphical approach to query languages.
A host language is a programming
language for writing application
programs containing commands from a
query language.
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Database Use in Information
Systems
Information System
Data Management
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Types of Databases
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Personal databases are generally used
by only one person.
Shared databases are used by many
users at one time.
To prevent users from processing data
they do not need, the database is
divided into views.
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Data Warehouses
Information System
Data Management
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Data Warehouses
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A data warehouse is a collection of data
drawn from other databases used by
the business.
A data mart represents the specific data
from a data warehouse which a user
needs.
Data mining is the technique of
searching for patterns in the data.
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Multidimensional Databases
Information System
Data Management
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Multidimensional Databases
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A multidimensional database presents
the data to the user in several
dimensions. A three dimensional
database might present the information
by
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Sales Region
Season
Product Line
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On-Line Analytical Processing
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On-Line Analytical Processing (OLAP)
permits users to “slice and dice” large
amounts of data in databases, data
warehouses, and multidimensional
databases using a variety of techniques,
including statistical techniques.
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Database Administration
Information System
Data Management
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Database Administration
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An organization with large databases
often has a Database Administrator
(DBA) who is responsible for managing
the organization’s database.
The DBA designs the databases based
on the needs of the users.
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Information Systems Data
Management
Key Terms
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Key Terms
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Application Generator
Database
Database Administrator
(DBA)
Database Management
System (DBMS)
Data Mart
Data Mining
Data Warehouse
© 2001 Business & Information Systems 2/e
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Data Validation
Direct (Random) File
Distributed Database
Hierarchical Database
Host Language
Indexed File
Key Field
Many-to-Many
Relationship
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Key Terms (cont’d.)
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Multidimensional
Database
Network Database
Object-Oriented
Database
Object-Relational
Database
One-to-Many
Relationship
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One-to-One
Relationship
On-line Analytical
Processing (OLAP)
Personal Database
Primary Key
Query-by-Example
(QBE)
Query Language
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Key Terms (cont’d.)
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Relational Database
Relationship
Sequential File
Shared Database
SQL
View
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Summary
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File Processing
Database Processing
Database Organization
Common Database Software
Using Database Software
Database Use in Information Systems
© 2001 Business & Information Systems 2/e
37
Summary (cont’d.)
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Data Warehouses
Multidimensional Databases
Database Administration
© 2001 Business & Information Systems 2/e
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Final Black Slide