#DBMS whatisdbms whatpurposetousedbms explaindbms

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DBMS

What is DBMS?

Database Management System (DBMS) is a software for storing and retrieving users’ data while considering appropriate security measures. It consists of a group of programs which manipulate the database. The DBMS accepts the request for data from an application and instructs the operating system to provide the specific data. In large systems, a DBMS helps users and other third-party software to store and retrieve data.

DBMS allows users to create their own databases as per their requirement. The term “DBMS” includes the user of the database and other application programs. It provides an interface between the data and the software application.

Example of a DBMS

Let us see a simple example of a university database. This database is maintaining information concerning students, courses, and grades in a university environment. The database is organized as five files:

The STUDENT file stores data of     each student

The COURSE file stores contain     data on each course.

The SECTION stores the     information about sections in a particular course.

The GRADE file stores the     grades which students receive in the various sections

The TUTOR file contains     information about each professor.

To define DBMS:

We need to specify the     structure of the records of each file by defining the different types of     data elements to be stored in each record.

We can also use a coding scheme     to represent the values of a data item.

Basically, your Database will     have 5 tables with a foreign key defined amongst the various tables.

History of DBMS

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Here, are the important landmarks from the history:

1960 – Charles Bachman designed     first DBMS system

1970 – Codd introduced IBM’S     Information Management System (IMS)

1976- Peter Chen coined and     defined the Entity-relationship model also know as the ER model

1980 – Relational Model becomes     a widely accepted database component

1985- Object-oriented DBMS     develops.

1990s- Incorporation of     object-orientation in relational DBMS.

1991- Microsoft ships MS     access, a personal DBMS and that displaces all other personal DBMS     products.

1995: First Internet database     applications

1997: XML applied to database     processing. Many vendors begin to integrate XML into DBMS products.

Characteristics of DBMS

Here are the characteristics and properties of Database Management System:

Provides security and removes     redundancy

Self-describing nature of a     database system

Insulation between programs and     data abstraction

Support of multiple views of     the data

Sharing of data and multiuser     transaction processing

Database Management Software allows     entities and relations among them to form tables.

It follows the ACID concept (     Atomicity, Consistency, Isolation, and Durability).

DBMS supports multi-user     environment that allows users to access and manipulate data in parallel.

Types of DBMS

Tha main Four Types of Database Management System are:

Hierarchical database

Network database

Relational database

Object-Oriented database

In a Hierarchical database, model data is organized in a tree-like structure. Data is Stored Hierarchically (top down or bottom up) format. Data is represented using a parent-child relationship. In Hierarchical DBMS parent may have many children, but children have only one parent.

The network database model allows each child to have multiple parents. It helps you to address the need to model more complex relationships like as the orders/parts many-to-many relationship. In this model, entities are organized in a graph which can be accessed through several paths.

Relational DBMS is the most widely used DBMS model because it is one of the easiest. This model is based on normalizing data in the rows and columns of the tables. Relational model stored in fixed structures and manipulated using SQL.

In Object-oriented Model data stored in the form of objects. The structure which is called classes which display data within it. It is one of the components of DBMS that defines a database as a collection of objects which stores both data members values and operations.

Advantages of DBMS

DBMS offers a variety of     techniques to store & retrieve data

DBMS serves as an efficient     handler to balance the needs of multiple applications using the same data

Uniform administration     procedures for data

Application programmers never     exposed to details of data representation and storage.

A DBMS uses various powerful     functions to store and retrieve data efficiently.

Offers Data Integrity and     Security

The DBMS implies integrity     constraints to get a high level of protection against prohibited access to     data.

A DBMS schedules concurrent     access to the data in such a manner that only one user can access the same     data at a time

Reduced Application Development     Time

Disadvantage of DBMS

DBMS may offer plenty of advantages but, it has certain flaws-

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Cost of Hardware and Software     of a DBMS is quite high which increases the budget of your organization.

Most database management     systems are often complex systems, so the training for users to use the     DBMS is required.

In some organizations, all data     is integrated into a single database which can be damaged because of     electric failure or database is corrupted on the storage media

Use of the same program at a     time by many users sometimes lead to the loss of some data.

DBMS can’t perform     sophisticated calculations

When not to use a DBMS system?

Although, DBMS system is useful. It is still not suited for specific task mentioned below:

Not recommended when you do not have the budget or the expertise to operate a DBMS. In such cases, Excel/CSV/Flat Files could do just fine.