The DBMS (Database Management System)and the Internet

DBMS and the internet

Inroduction

Database management system and its implications on the internet is a very vast

subject . This essay tries to describe the genesis and evolution of database management

systems concept . The main theories underlying DBMS , the contributors to evolution and

development of DBMS , and finally examples of DBMS as a result of these contributions

Fast and accurate utilization , understanding , and interpretation of data and deriving

results from it is one of the most marvelous gifts of computer science to the mankind

As a

matter of fact it was the necessity to analyze data on census of USA which gave

birth to first computer on this world

Data is information gathered on a particular subject . A simple example is the

Information on the employees of a company . A software program is devised to generate

the salary of the employee , based on the data of each employee . This software is a

system , which manages the data to get the desired result i .e calculates the salary based on

the variables of the data on the employee , like , his designation , attendance , deduction

against advances , no . of years in service etc . In early days before the personal computers

arrived , data was fed into the computer by punched cards and the management was done

by batch processing . Since the personal computers arrived the way data is managed

has changed substantially , to get fast easy and accurate results

The idea of establishing relations amongst databases was first proposed by E . F . Codd

in 1970 . The tool he used was relational algebra to form a relational model . In mid

1970s Moche M Zloof developed the query by example , a language for

relational databases (QBE , 2006

E .F .Codd

Let us first examine the contribution of E . F . Codd in DBMS

He was a British scientist who created relational databases while working at the IBM (E .Codd

2006 ) The fundamental assumption of the relational model is that all data are represented

as n-ary relations , an n-ray being a subset of Cartesian product of n domains . In the

mathematical model reasoning about such data is done in two-valued predicated logic

meaning there are two possible evaluations for each proposition : either true or false ( The

model , 2006

The relational model of data permits the database designer to create a consistent

logical representation of information . Consistency is achieved by including declared

theory includes a process of database normalization , whereby a design with certain desirable

constraints in the database design , which is usually referred to as logical schema . The

properties can be s elected from set of logically equivalent alternatives . The access plans

and other implementation and operation details are handled by DBMS engine , and are not

reflected in the logical model . This is in contrast to the common practice for the SQL

DBMSs in which performance tuning often requires changes to logical model (The

model ,2006

The basic relation building block is domain or type . A tuple is an uned set of

Attribute values .An attribute is...