DBMS Basics & DBMS Vs File System

DBMS Basics

GUIDBM subject is nearly in all the computer related graduation field so i thought to share my knowledge in the subject as from last five years i am teaching the same subject.

First i will start with the DBMS latter i will cover GUI.

Lets Start with the basics:

Database Basics:

Databases and database systems have become an essential component of everyday life.Daily in our life, most of us encounter several activities that involve some interaction with a database. for example we are checking our account balance on the internet, booking online ticket, online railway,airplane reservation , taking admission at university though internet, checking the result on the net etc.
As the list illustrates you can yourself figure out, databases form an essential part of almost all enterprises today.

Definition:
"A database-management system (DBMS) is a collection of interrelated data and a
set of programs to access those data" (Korth volume 1)

"A database is a collection of related data (Note 1). By data, we mean known facts that can be recorded and that have implicit meaning" (Navathe 3rd Edition)

Note:both the definition i have taken from book mentioned in the bracket.

in the first definition the collection of data can be anything like information related to an enterprise or information related to an account etc. and data means consider the names, telephone numbers, and addresses of the people you know. You may have stored it on a personal computer and software such as ACCESS or EXCEL. This is a collection of related data with an implicit meaning and hence is a database.


After the database basics we must know the problem arise in traditional file system. One can say that database is invented to solve the problems of the file system.

Database Systems versus File Systems:

• Data redundancy and inconsistency
This is the major problem of file system.the same information may be duplicated in
several places (files).
• Difficulty in accessing data
File processing system not allowed the convenient way of data retrieval.
• Data isolation
In file processing system writing new application is very difficult because here data is scattered in different file.
• Integrity problems
Sometime constraint are require on the data item, example balance of account should be greater than 5000. Giving such type of constraint in the file system is very difficult.
• Atomicity problems
In file processing system it is very difficult to maintain the atomicity.
Atomicity means if transaction fails because of some reason all the file must be consistence.
• Concurrent-access anomalies
There is consistency problem in the file system if many user accessing the same file simultaneously.
• Security problems
In the file system every user have the access to other user file. So one user can easily delete or see the details of other user.