Database Management System

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.

History of DBMS

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 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
• DBMS 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.

Popular DBMS Software

Here, is the list of some popular DBMS system:

• MySQL
• Microsoft Access
• Oracle
• PostgreSQL
• dBASE
• FoxPro
• SQLite
• IBM DB2
• LibreOffice Base
• MariaDB
• Microsoft SQL Server etc.

Types of DBMS

1. Hierarchical DBMS

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.

2. Network Model

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.

3. Relational Model

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.

4. Object-Oriented Model

In Object-oriented Model data stored in the form of objects. The structure which is called classes which display data within it. It 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

• 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.

Key Difference:

• A database is a collection of related data which represents some aspect of the real world.
• Database Management System (also known as DBMS) is a software for storing and retrieving users’ data by considering appropriate security measures.
• DBMS Provides security and removes redundancy.
• DBMS has many advantages over tradition Flat File management system.
• End-Users, Application Programmers, and Database Administrators are they type of users who access a DBMS.
• DMBS is widely used in Banking, Airlines, Telecommunication, Finance and other industries.
• Four Types of DBMS systems are 1) Hierarchical 2) Network 3) Relational 4) Object-Oriented DBMS.
• DBMS serves as an efficient handler to balance the needs of multiple applications using the same data.
• Cost of Hardware and Software of a DBMS is quite high which increases the budget of your organization.

Components of Data Base Management System

Organizations produce and gather data as they operate. Contained in a database, data is typically organized to model relevant aspects of reality in a way that supports processes requiring this information.

The database management system can be divided into five major components, they are:

• Hardware
• Software
• Data
• Procedures
• Database Access Language

Let’s have a simple diagram to see how they all fit together to form a database management system.

1. Hardware

When we say Hardware, we mean computer, hard disks, I/O channels for data, and any other physical component involved before any data is successfully stored into the memory.

When we run Oracle or MySQL on our personal computer, then our computer’s Hard Disk, our Keyboard using which we type in all the commands, our computer’s RAM, ROM all become a part of the DBMS hardware.

2. Software

This is the main component, as this is the program which controls everything. The DBMS software is more like a wrapper around the physical database, which provides us with an easy-to-use interface to store, access and update data.

The DBMS software is capable of understanding the Database Access Language and intrepret it into actual database commands to execute them on the DB.

3. Data

Data is that resource, for which DBMS was designed. The motive behind the creation of DBMS was to store and utilise data.

In a typical Database, the user saved Data is present and meta data is stored.

Metadata is data about the data. This is information stored by the DBMS to better understand the data stored in it.

For example: When I store my Name in a database, the DBMS will store when the name was stored in the database, what is the size of the name, is it stored as related data to some other data, or is it independent, all this information is metadata.

4. Procedures

Procedures refer to general instructions to use a database management system. This includes procedures to setup and install a DBMS, To login and logout of DBMS software, to manage databases, to take backups, generating reports etc.

5. Database Access Language

Database Access Language is a simple language designed to write commands to access, insert, update and delete data stored in any database.

A user can write commands in the Database Access Language and submit it to the DBMS for execution, which is then translated and executed by the DBMS.

User can create new databases, tables, insert data, fetch stored data, update data and delete the data using the access language.

Users

• Database Administrators: Database Administrator or DBA is the one who manages the complete database management system. DBA takes care of the security of the DBMS, it’s availability, managing the license keys, managing user accounts and access etc.
• Application Programmer or Software Developer: This user group is involved in developing and desiging the parts of DBMS.
• End User: These days all the modern applications, web or mobile, store user data. How do you think they do it? Yes, applications are programmed in such a way that they collect user data and store the data on DBMS systems running on their server. End users are the one who store, retrieve, update and delete data.