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IT 5433 LM1
Learning Objectives
• Understand key terms in database
• Explain file processing systems
• List parts of a database environment
• Explain types of database develop approaches
Database Management System
• A database management system is the software system that allows
users to define, create and maintain a database and provides controlled
access to the data.
• A Database Management System (DBMS) is basically a collection of
programs that enables users to store, modify, and extract information
from a database as per the requirements.
http://ecomputernotes.com/fundamental/what-is-adatabase/advantages-and-disadvantages-of-dbms
Traditional File Storage Method
The File Storage Method is a group of files storing data of
an organization.
http://ecomputernotes.com/fundamental/what-is-adatabase/traditional-file-processing-system
Important Characteristics of File
Processing System
• Each file is independent from one another.
• Each file is called a flat file.
• Each file contained and processed information for one specific function,
such as accounting or inventory.
• Files are designed by using programs written in programming languages
such as COBOL, C, C++.
• The physical implementation and access procedures are written into
database application; therefore, physical changes resulted in intensive
rework on the part of the programmer.
• As systems became more complex, file processing systems offered little
flexibility, presented many limitations, and were difficult to maintain.
http://ecomputernotes.com/fundamental/what-is-adatabase/traditional-file-processing-system
Limitations of the File Processing System I FileBased Approach
1. Separated and Isolated Data
6. Incompatible file formats
2. Duplication of data
7. Data Security
3. Data Dependence
8. Transactional Problems
4. Difficulty in representing data from the user's view
9. Concurrency problems
5. Data Inflexibility
10. Poor data modeling of real world
http://ecomputernotes.com/fundamental/what-is-adatabase/traditional-file-processing-system
Components of the Database System
Environment
There are five major components in the database system environment
• Hardware
• Software
• Data
• Users
• Procedures
http://ecomputernotes.com/fundamental/what-is-adatabase/advantages-and-disadvantages-of-dbms
Components in the Database System
Environment
• Hardware - the actual computer system used for keeping and
accessing the database.
• Software - the actual DBMS.
• Data - the most important component of DBMS environment from
the end users point of view
http://ecomputernotes.com/fundamental/what-is-adatabase/advantages-and-disadvantages-of-dbms
Components in the Database System
Environment
• Users – individuals who can access or retrieve data on demand using the applications and
interfaces provided by the DBMS. The users can be:
 Naive Users - users who need not be aware of the presence of the database system or any other system
supporting their usage.
 Online Users - those who may communicate with the database directly via an online terminal or indirectly via
a user interface and application program.
 Application Programmers - those who are responsible for developing application programs or user interface.
 Sophisticated Users - users who interact with the system without ,writing programs. Instead, they form their
requests in database query language.
 Data Base Administrator (DBA) - the person or group in charge for implementing the database system ,within
an organization.
• Procedures - the instructions and rules that govern the design and use of the database.
http://ecomputernotes.com/fundamental/what-is-adatabase/advantages-and-disadvantages-of-dbms
Type of Database Systems
On the basis of the number of users:
• Single-user DBMS
• Multi-user DBMS
On the basis of the site location
• Centralized DBMS
• Parallel DBMS
• Distributed DBMS
• Client/server DBMS
http://ecomputernotes.com/fundamental/what-is-adatabase/type-of-database-system
Users
• Single-user DBMS - the database resides on one computer and is only
accessed by one user at a time. This one user may design, maintain,
and write database programs.
• Multi-user DBMS - the data are both integrated and shared. A
database is integrated when the same information is not recorded in
two places.
http://ecomputernotes.com/fundamental/what-is-adatabase/type-of-database-system
Site Location
• The centralized database system consists of a single processor
together with its associated data storage devices and other
peripherals.
• Parallel database system architecture consists of a multiple Central
Processing Units (CPUs) and data storage disk in parallel.
http://ecomputernotes.com/fundamental/what-is-adatabase/type-of-database-system
Site Location
• A logically interrelated collection of shared data physically distributed over
a computer network is called a distributed database and the software
system that permits the management of the distributed database and
makes the distribution transparent to users is called a Distributed DBMS.
• Client/Server architecture of database system has two logical components
namely client, and server. Clients are generally personal computers or
workstations whereas server is large workstations, mini range computer
system or a mainframe computer system. The applications and tools of
DBMS run on one or more client platforms, while the DBMS soft wares
reside on the server. The server computer is caned backend and the client's
computer is called front end.
http://ecomputernotes.com/fundamental/what-is-adatabase/type-of-database-system