Over view of DATABASE

File Processing System

Data stored in files used to represent information

Example of File management system is COBOL

But at 1960 C, C++ where not develop so COBOL was popular at that time, So Cobol is example (Common Business Oriented Language)

Files are used to transfer the data from one place to another place, but not use for storage Purpose.

Disadvantages

More Redundancy (duplication of data)

More inconsistency

If the customer address has been changed, so he informs to car loans but did not inform to Home Loan and Personal Loan so that is Inconsistency (Wrong Data)

Less security

Lengthy development

File management system takes more time for developing application. When development time increases, cost of the application also increases.

It does not support primary key, foreign key because duplicates values are accepted here

It will not support error handling

It will not support data type

To overcome this we have Data Base

It is a collection of meaningful information stored in one location

It is managed by DBMS

Types of DBMS

HDBMS (Hierarchical)

Developed in 1960

It organizes data in a tree structure

Data manipulation and retrieval is faster

This model supports one to many relations, But many to one relation is not possible, with this drawback Network Data Model came into existence.

Disadvantages

Data redundancy (duplication of Data)

This supports only one to many relationships

Network Data Model

It supports all types of relationships

Here data is represented in the form of Nodes. In this physical link is must to communicate the data. If there is any physical link missing total data will be lost.

Drawbacks:

Accessing data and data manipulation is difficult. If any value is Deleted then value dependency upon deletion value will not be rearranged with this drawback Relational Data Model came into existence.

Relational Database Model

This model is introduced by “E.F CODD”

He design some rules called CODD Rules

A database which satisfies all CODD Rules are called as RDBMS

Features:

 Provides high security

Supports error handling

No redundancy

Supports ACID properties

ORDBMS

Which stands for object Relational DBMS?

It is not a New System. It is an extension to RDBMS

User defined Types is introduced by ORDBMS

Addr

{ H.no

Street

City

State

}

OODBMS(OBJECT ORIENTED)

It is entirely based on OOPS

Here data is represented in the form of class and objects

Sql server

It is database server software

It is DBMS

It is back end tool

It is RDBMS and ORDBMS

It is Application Software

DDL

CREATE

ALTER

DROP

DML

     INSERT

     UPDATE

     DELETE

DRL

     SELECT

TCL

     SAVE TRANSACTION

     ROLLBACK

     COMMIT

DCL

     GRANT

     REVOKE

     DENY