Database Management System and It's Objectives

A database management system (DBMS) consists of collection of interrelated data and a set of programs to access that data. It is software that is helpful in maintaining and utilizing a database.

A DBMS consists of:

1. A collection of interrelated and persistent data. This part of DBMS is referred to as database (DB).
2. A set of application programs used to access, update, and manage data. This part constitutes data management system (MS).
3. A DBMS is general-purpose software i.e., not application specific. The same DBMS (e.g., Oracle, Sybase, etc.) can be used in railway reservation system, library management, university, etc.
4. A DBMS takes care of storing and accessing data, leaving only application specific tasks to application programs.

DBMS is a complex system that allows a user to do many things to data as shown in below figure

From this figure, it is evident that DBMS allows user to input data, share the data, edit the data, manipulate the data, and display the data in the database. Because a DBMS allows more than one user to share the data; the complexity extends to its design and implementation.

Structure of DBMS

An overview of the structure of database management system is shown in below figure. A DBMS is a software package, which translates data from its logical representation to its physical representation and back. The DBMS uses an application specific database description to define this translation. The database description is generated by a database designer

from his or her conceptual view of the database, which is called the Conceptual Schema. The translation from the conceptual schema to the database description is performed using a data definition language (DDL) or a graphical or textual design interface.

Objectives of DBMS

The main objectives of database management system are data availability, data integrity, data security, and data independence.

1.Data Availability

Data availability refers to the fact that the data are made available to wide variety of users in a meaningful format at reasonable cost so that the users can easily access the data.

2. Data Integrity

Data integrity refers to the correctness of the data in the database. In other words, the data available in the database is a reliable data.

3 .Data Security

Data security refers to the fact that only authorized users can access the data. Data security can be enforced by passwords. If two separate users are accessing a particular data at the same time, the DBMS must not allow them to make conflicting changes.

4. Data Independence

DBMS allows the user to store, update, and retrieve data in an efficient manner. DBMS provides an “abstract view” of how the data is stored in the database.

In order to store the information efficiently, complex data structures are used to represent the data. The system hides certain details of how the data are stored and maintained.