A shared collection of logically related data, designed to meet the information needs of multiple users in an organization.

from above definition of database it is shared collection means all the data in the database is shared by all all the users of the database, logically related means all data is related ,some rules,constraint are implemented on the data so that data is retrieve as information so to meets information need of an organization.

Basic Terms







< h3>Data

Data is raw facts and figures, for example number of emplyees in an sales department of an organization but this give not clue about there salary ,age qualification,designation etc.

Information

Information is processes data after doing any calculation computation or any formal process, information is derived from data.for example if we take date of birth of any emplotee in sales department of an orgranization then we can easily find its age, or we also find its retirement date.

Schema

Schema or database schema is the overall structure if the database or how data is created,maintained and modified.For example defining a database of an emplyee we decide that name,age,salary and department number information is stored then schema definition is that name is stored in text,age and salary are stored in numbers and department number istored in text with number.

Instance

Instance is data ptrsent at particular moment in database.For example if we retrieve name and salary of an employee from database,the particular data comes from database is instance.

DBMS

DBMS or database maangement system is the set of tool or program that manage whole database whether it is creation of database ,storing of data,maintenance of data,give access and authentication to the different users.

Whenever name of DBMS comes it means two things.

Data maangement

Data maangement means creation of database,storing data in database,retrieving of data,deletion of data and also database,modification of data,backup and recovery of data .

User management

User maangement facility is provided by DBMS are creation of new users and deletion of old users,authentication and authorization,give different type of access to the user for creating,modifying and retrieval of data from database.

Database user

Application programmer

Application programmer are those user who write application program to provide access to database or write specific application using database.

End User

End User are those user that acess database for different purposes, they can either access database or modify it.

Native user









Native user are general user that uses database for simple operation or by accessing application program or even they generally does not know that they uses database for there purpose.

Sophisticated user

Sophisticated user are those users which access database through application program or they have speical rights to access internal structure of database, they generally top management person’s.

Database Administrator

Database Administratoror DBA is professional person or user that has given duty of maintenance of database at regular interval,It tasks are schema definition,user maangement ,authentication,authorization,backup and recovery.