DATABASE THEORY

APA Introduction

Database is a term abbreviated as DB is a collection of information which is entered into the computer in an organized method to enable the computer to access to the data quickly . Each piece of information is stored as data with the terms named as fields , records and s . The collection of fields is called as record whereas the collection of records is called as . The entire set of data storage is called as electronic filing system . To enter , select or retrieve data from the database , a system of

Database Management System (DBMS ) is practiced which details how a particular set of data is to be accessed in an organized method from the computer . Another concept of database is called as Hypertext wherein a piece of graphic , text or picture can be stored in a systematic method which is increasingly useful in internet web designing . Each database is designed according to the type of facts required to be input into the fields , such of which is called as `schema . Schema describes the objects , representation and relation to the database . Further organization of schema is called as `database models

SQL and Oracle database models have been effective , efficient and user-friendly which is being used widely in the present tech-savvy working world . Apart from the facility of storing large volumes of data , these applications offer high performance and a greater degree of accuracy . Database models use application software which is called as Application Programming Interface (API ) to retrieve information stored in a database . The common platforms of APIs are JDBC (Java Database Connectivity ) and ODBC (Open Database Connectivity

DBMS is increasingly useful in maintenance of customer records in super-mar , patient records in hospitals [name , DOA , diagnosis prescription , results and response of the patient etc ,] , educational institutions , industrial and corporate sector [biotechnology , hotels airports , FMCG] to keep a track of stocks , inventory control and shareholders details . Almost every work area is entitled to draw the benefit of DBMS for a methodical way of storing and maintenance of records in its respective product . DBMS has proved to be an effective tool for storing data and also has reduced the labor of manual maintenance of records

Models of Database

For selection of a model of database , application area , structure degree of performance and limitations are the pre-requisites . Some of the database models are discussed as

Flat Model

This model consists of table where rows and columns [similar to spreadsheet] contain the data as well as the password for each individual user , while defining the type of data [character , integers floating numbers]

Hierarchical model

This model is widely used in desktop computer filing system . However , it is not considered for certain database operations

Network model

This model organizes data in records and sets as pre-set by CODASYL Records are maintained in hierarchical structure [COBOL] . This database can be simplified in such a way that there is one owner [one record] and many members [sets]

Relational model

In this model , mostly used...