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Chapter 7
Information SystemData Management
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Our Agenda 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.) Data Warehouses Multidimensional Databases Database Administration
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Learning Objectives 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.) 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.) 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 SystemData Management
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File Processing 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 A file can be organized in
secondary storage as a: 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.) A file can be organized in
secondary storage as a: 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 Managing data files requires that
the data be kept up to date. To do so requires: Modifying, or updating, records
involves 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 Advantages
Simple to use. Disadvantages
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 SystemData Management
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Database Processing 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 Advantages
Duplication of data is reduced. Easier to process different groups of
data. Not dependent on the organization of
data in the database. Disadvantages
Expensive. More vulnerable than file processing. Can be complex to develop.
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Database Organization
Information SystemData Management
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Data Relationships One-to-one relationship
One group of data is related on only one other group of data.
One-to-many relationship One group of data is related to one or
more other groups of data. Many-to-many relationship
One or more groups of data is related to one or more other groups of data.
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Types of Databases Hierarchical database Network database Relational database Object-oriented database Object-relational database
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Common Database Software
Information SystemData Management
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Common Database Software Personal Computer
dBASE Access FoxPro Approach Fourth Dimension Oracle
Networked Systems Oracle Sybase SQL Server Informix GemStone ObjectStore Versant ODBMS
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Using Database Software
Information SystemData Management
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Using Database Software Query languages – allows a user to
query a database. 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 SystemData Management
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Types of Databases 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 SystemData Management
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Data Warehouses 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 SystemData Management
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Multidimensional Databases A multidimensional database
presents the data to the user in several dimensions. A three dimensional database might present the information by Sales Region Season Product Line
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On-Line Analytical Processing 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 SystemData Management
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Database Administration 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 Application Generator Database Database Administrator (DBA) Database Management System (DBMS) Data Mart Data Mining Data Warehouse
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.) Multidimensional Database Network Database Object-Oriented Database Object-Relational Database One-to-Many Relationship
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.) Relational Database Relationship Sequential File Shared Database SQL View
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Summary File Processing Database Processing Database Organization Common Database Software Using Database Software Database Use in Information
Systems
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Summary (cont’d.) Data Warehouses Multidimensional Databases Database Administration
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