What is Database Management System ?

  Data

Data is a Collection of facts, which is in unorganaized but they can be organized into useful form.

                    

 Data is tow types

1.         Row data: it is data which are collected form different sources and has no meannig.
2.           Derived Data:it is a data that are extracted form row data nad for getting useful information.

DataBase

              A Database is a collection of interrelated data.

•      A Database is designed, built and populated with data for a specific purpose.
•      A Database can be of any size and of varying complexity.

 
 Database Management System(DBMS)

            DBMS is a collection of programs that enables users to create and maintain a database. that enables users to create and maintain a database. The DBMS is hence a general- purpose software system that facilitates the process of definnig, constructing and manipulating database for varius applications.  

Database Characteristics

•  Represents complex relationship between data
• Controls data redundancy.
• Enforces user defined rules.
• Enforces data sharing .
• it has automatric and intelligent backup and recovery procedures.
• it has central dictionary to store information.
• Pertaining to data and its mainpulation .
• it has different interfaces via which user can manipulate the data.
• Enforces data access authorization.

 Componentes of database

    The figure given below shows the componentse of the database.

               

             

 

The importent components are

1. User
2. DBMS software
3. Database
4. Hardware
5. Database administrator

1. User

        Users or endusers are people who need data from the database for their applications. the user request the database for thier applicatrions. The user requests the DBMS software for data through query languages or application program such as visualbasic,java, etc., 

    2.Database administrator(DBA)

      Database administrator is a privileged user who is incharge of DBMS. The DBA has privilages that are not given to ordinary users.

       3.DBMS software

        This software acts as a middle man between user and the database. The following are the importent functions.

•    it gets the request form the users, translates into database request and give response to the uses.
•    it shares the database among multiple users. 

4.Database

        Database is defined as a collection of interrelated data stored in tables. there are tow types of data. they are,

• Enduser data
• Meta data

Enduser data are row facts of an user. Metadata are data about data. this includes data definition, datatypes,

relationship between data etc.

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