CH.PRANAVICOMPUTER SCIENCE ENGG

PREVIOUS HISTORY OF DBMS Before the concept of DBMS, they used to store

the data (i.e information) in the form of written copies and store them....

This made the retrieve process very difficult.

It made wastage of paper, files, storage and precious time.

CONCEPT OF DBMS... In order to make the retrieving process easy,

the concept of was DBMS raised .

The introduction of term database coincided

from the mid-1960s onwards.

As computers grew in speed and capability, a number of general-purpose database systems emerged; by the mid-1960s a number of such systems had come into commercial use.

In 1971 the Database Task Group delivered their standard known as "CODASYL approach“.

Both concepts later became known as

NAVIGATIONAL DATABASES due tothe way data was accessed.

IBM also had their own DBMS in 1968, known as Information Management System (IMS).

• CHARLES BACHMAN, was awarded with

ACM TURING award in 1973, for his work on development of

“DATABASE MANAGEMENT SYSTEMS.”

BEFORE... AFTER...

What is DBMS???

A Database Management System (DBMS) is a software system designed to store, manage, and facilitate access to databases….

(or)

A database management system (DBMS) is a set of related software applications that provide end users and application programmers with a systematic way to create and manage databases.

IN GENERAL TERMS.....Data base management system is nothing but

storing of data which we can access whenever we will need.

Collection of inter-related data.

It provides an convenient environment for the efficient use.

Database touch all aspects of our day to day life.

In modern days business, data base management system can be never avoided.

APPLICATIONS OF DBMS....Banking: for transactions

Airlines: reservation and schedules

Tele communications: for retrieving data of user

Credit card: for transactions

Universities: registration, retrieving marks, applications, grades

Human resources: employee records, salaries, tax deductions,

RDBMS...• Most popular database system.

• Simple and sound theoretical basis.

• Developed by E F Codd in the early 1970's.

• The model is based on tables, rows and columns and the manipulation of data stored within.

• Relational database is a collection of these tables.

• First commercial system: MULTICS in 1978.

• Has overtaken Hierarchical and Network models.

• Main feature: Single database can be spread across several tables.

• Examples include: Oracle, IBM's DB2, Sybase, MySQL & Microsoft Access.

RDBMS Advantages • Increases the sharing of data and faster development of new applications

• Support a simple data structure, namely tables or relations

• Limit redundancy or replication of data

• Better integrity as data inconsistencies are avoided by storing data in one place

• Provide physical data independence so users do not have to be aware of underlying objects

• Offer logical database independence - data can be viewed in different ways by different users.

• Expandability is relatively easy to achieve by adding new views of the data as they are required.

• Support one off queries using SQL or other appropriate language.

• Better backup and recovery procedures

• Provides multiple interfaces

• Solves many problems created by other data models

• The ability to handle efficiently simple data types

• Multiple users can access which is not possible in DBMS

RDBMS Disadvantages

• Software is expensive

• Complex software means expensive hardware

• Requires skilled knowledge to implement

• Certain applications are slower processing

• Increased vulnerability

• More difficult to recover if data is lost

• Seen as a poor representation of the real world

• Difficult to represent hierarchies

• Difficult to represent complex data type.

DBMS

Data is stored in a single large table

Single record modification affects the whole database

RDBMS

Database is 'broken down' into smaller pieces

The changes will not affect the entire database

DATABASE LANGUAGE

SQL…The most basic Oracle Database utility

A Basic command-line interface

The first thing you work with it in Oracle DBMS

What is SQL?

– When a user wants to get some

information from a database file, he

can issue a query.

– A query is a user–request to retrieve

data or information with a certain

condition.

– SQL is a query language that allows

user to specify the conditions. (instead

of algorithms)

INTRODUCTION TO SQL…

Concept of SQL

– The user specifies a certain condition.

– The result of the query will then be

stored in form of a table.

– Statistical information of the data.

– The program will go through all the

records in the database file and

select those records that satisfy the

condition.(searching).

STRUCTURED QUERY LANGUAGE ...

Relational Database Management Systems use the language known as SQL

SQL is a simple programming language used for accessing and managing data in relational databases.

Developed by IBM in 1970 to support its various relational products.

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