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DBMS

ASSIGNMENT #1: (in a short coupon bond / computerized or handwritten)

1. Define the following terms:

a. Data

b. Information

c. Database

d. Structured data

e. Unstructured data

f. Metadata

g. Database Management System

h. Traditional File Processing System

i. Database Approach

j. Database Application

2. Range of Database Applications


Chapter 1: The Database Environment
Modern Database Management
9th Edition
Jeffrey A. Hoffer, Mary B. Prescott,

Definitions
•Database: organized collection of logically related data
•Data: stored representations of meaningful objects and events
–Structured: numbers, text, dates
–Unstructured: images, video, documents
•Information: data processed to increase knowledge in the person using the data
•Metadata: data that describes the properties and context of user data

Figure 1-1a Data in context

Context helps users understand data

Figure 1-1b Summarized data

Graphical displays turn data into useful information that managers can use for decision making and interpretation


Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and data context

Disadvantages of File Processing
•Program-Data Dependence
–All programs maintain metadata for each file they use
•Duplication of Data
–Different systems/programs have separate copies of the same data
•Limited Data Sharing
–No centralized control of data
•Lengthy Development Times
–Programmers must design their own file formats
•Excessive Program Maintenance
–80% of information systems budget

Problems with Data Dependency
•Each application programmer must maintain his/her own data
•Each application program needs to include code for the metadata of each file
•Each application program must have its own processing routines for reading, inserting, updating, and deleting data
•Lack of coordination and central control
•Non-standard file formats

Problems with Data Redundancy
•Waste of space to have duplicate data
•Causes more maintenance headaches
•The biggest problem:
–Data changes in one file could cause inconsistencies
–Compromises in data integrity

SOLUTION: The DATABASE Approach
•Central repository of shared data
•Data is managed by a controlling agent
•Stored in a standardized, convenient form
Requires a Database Management System (DBMS)

Database Management System
DBMS manages data resources like an operating system manages hardware resources
A software system that is used to create, maintain, and provide controlled access to user databases

Advantages of the Database Approach
•Program-data independence
•Planned data redundancy
•Improved data consistency
•Improved data sharing
•Increased application development productivity
•Enforcement of standards
•Improved data quality
•Improved data accessibility and responsiveness
•Reduced program maintenance
•Improved decision support

Costs and Risks of the Database Approach
•New, specialized personnel
•Installation and management cost and complexity
•Conversion costs
•Need for explicit backup and recovery
•Organizational conflict

Components of the Database Environment
•CASE Tools–computer-aided software engineering
•Repository–centralized storehouse of metadata
•Database Management System (DBMS) –software for managing the database
•Database–storehouse of the data
•Application Programs–software using the data
•User Interface–text and graphical displays to users
•Data/Database Administrators–personnel responsible for maintaining the database
•System Developers–personnel responsible for designing databases and software
•End Users–people who use the applications and databases

The Range of Database Applications
•Personal databases
•Workgroup databases
•Departmental/divisional databases
•Enterprise database
–Enterprise resource planning (ERP) systems
–Data warehousing implementations

Table 1-6 Summary of Database Applications