Objectives of database management system(DBMS)

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Objectives of database management system(DBMS)

PROBLEMS WITH FILE BASED SYSTEMS

If programs and files independently developed for each application in the organization, it leads to the following problems

• DATA REDUNDANCY-Some data may be duplicated in many files.

e.g.: Address of customer

• LACK OF DATA INTEGRITY- Duplicated data may be different in different files (New address in one file and old address in another file)

• DATA AVAILABILITY- May require search of number of files to access a specified data

• CONTROL BY MANAGEMENT-Difficult as data scattered across files.

All files should be accessed to find specified data

Aim of data base management systems is to reduce above problems

DATABASE AND DATABASE MANAGEMENT SYSTEM

DATA BASE is a collection of related data necessary to manage an organization (Excludes transient data).It models a data resource and is independent of applications

DATA BASE MANAGEMENT-is a set of procedures that manage the database and provides access to the database in the form required by the application program

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OBJECTIVES OF A DATABASE MANAGEMENT SYSTEM

•Data is an organizational resource. It should be collected, validated, protected, logically organized and stored with controlled redundancy. This is the organizational database

• One of the main objectives of DBMS is to facilitate sharing of a database by current and future applications

• DBMS must ensure data independence for programs

•Data independence to be provided to application programs

•Data independence allows

-Change of database without affecting application programs

-Change of hardware or system software without affecting application programs

-Sharing of data by different applications by providing views appropriate for the application

• Control of Redundancy - Avoid unnecessary duplication

• Relations between data items specified

• Data integrity - Preserve consistency of data values

• Data Security - Permit access to data to authorized users only

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