Shelly Cashman Series Discovering Computers 2003

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CHAPTER 8
Database Management and Information System
Objectives

• File Processing system
• Database Management system
• Categories of Databases
• Information system
• Categories of Information system

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Data and Information

• How are data and information related?

• Computers process data into information
• Data is a collection of unprocessed items
• Information is data that is organized and
  meaningful

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File Processing System

• Each department or area has its own set of files
• Records in one file usually do not related to any
  records in other file

WEAKNESS
DATA REDUNDANCY same data stored in multiple
file ? waste of resources
ISOLATED DATA data stored in separate file ?
difficult to share and update
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File Processing Vs Database
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Database Approach

• Many programs and users can share data in
  database
• Secures data so only authorized users can access
  certain data items

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Database Approach

• What is a database?

Database software also called Database
Management System (DBMS)
Collection of data organized so you can access,
retrieve, and use it
Database software allows you to
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Database

• Data Integrity / Data Accuracy

Garbage in

• Degree to which data is correct
• Garbage in, garbage out (GIGO)computer phrase
  that means you cannot create correct information
  from incorrect data

Garbage out
Data integrity is lost
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Database

• Advantages of the database

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Database Organizations

• Defines how data are stored

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Database Organizations

• Flat-file database

• Contain only one table
• Problem duplicated values
• Suitable for simple telephone and mailing lists

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Database Organizations

• Hierarchical database

• Much alike the directory-management system.
• Structure starts with a main table called the
  root.
• A parent can have multiple children but a child
  can have only one parent in each hierarchy.
• Data access is sequential

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Database

• The hierarchy of data

• Database contains files
• File contains records
• Record contains fields
• Field contains characters

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Database Organizations

• Network database

• An improvement of the hierarchical database
• Efficiently deal with data involving repeating
  groups
• Characteristic of Network Database
• Child record is referred to as member
• Parent record is called an owner

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Database Organizations

• Network database

• Weakness
• For adding and deleting a record ? needs to
  update both data and pointers
• Pointer ? is a value that specifies the location
  of a record in a file or in memory.

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Database Organizations

• Relational database

• Stores data in tables that consist of rows and
  columns
• Rows called tuples / records
• Columns called attributes / fields.
• Each column has unique name
• Each row has primary key
• Used terminology called relations

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Database Organizations

• Relational database

attributes/ fields
Primary key
records/ tuples
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Database Organizations

• Relational database

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Database Organizations

• Relational database

• Structured Query Language (SQL)

• Allows you to manage, update, and retrieve data
• Has special keywords and rules included in SQL
  statements

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Database Organizations

• Relational database

SQL statement
SELECT Jersey, PlayerNm, BirthPlace WHERE
SponsorID 1
SQL statement results
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Database Organizations

• Object-oriented database/ ODBMS

Object is item that contains data, as well as
actions that read or process data

• Can store more types of data
• Can access data faster

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• Object-oriented database/ ODBMS

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Information System

• Set of hardware, software, data, people, and
  procedures that work together to produce
  information

hardware
people

• Procedures are instructions users follow to
  accomplish activities

procedures
data
software
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Information System

• Office Information System

Sometimes called office automation
Enables employees to perform tasks using
computers and other electronic devices instead of
manual methods.
Users create graphics and documents, send
messages, schedule appointments, and browse the
Web
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Information System

• Transaction Processing System (TPS)

• Keep track and process business activities
• Types of TPS
• Batch processing
• Transactions are collected into batch and
  processed at a time
• Has transaction files and master files
• Has no direct user interaction
• Online Transaction Processing (OLTP)
• Computer processes transactions as they are
  entered into the system
• Ensure that the data is up-to-date

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Information System

• Management Information System

• Generates accurate, timely, and organized
  information so managers can
• keep track the progress.
• make decisions
• solve problems
• supervise activities
• Provide user with report

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• Types of reports
• Detailed report
• Summary report
• Exception report

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Information System

• Decision Support System

• Designed to help user analyze data and make
  decision.
• Combination of DBMS and system software ? provide
  UI for interaction

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Information System

• Expert System

• captures and stores knowledge of human experts
• imitates human reasoning and decision making
  processes

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