What is database?

Database

 Before we learn about a database, let us understand -

What is Data?

In simple words, data can be facts related to any object in consideration. For example, your name, age, height, weight, etc. are some data related to you. A picture, image, file, pdf, etc. can also be considered data.

What is a Database?

A database is a systematic collection of data. They support electronic storage and manipulation of data. Databases make data management easy.

Let us discuss a few examples: An online telephone directory uses a database to store data of people, phone numbers, other contact details. Your electricity service provider uses a database to manage billing, client-related issues, handle fault data, etc.

Let us also consider Facebook. It needs to store, manipulate, and present data related to members, their friends, member activities, messages, advertisements, and a lot more. We can provide a countless number of examples for the usage of databases.

What is SQL?

SQL is the standard language for dealing with Relational Databases. SQL can be used to insert, search, update, and delete database records. SQL can do lots of other operations, including optimizing and maintenance of databases. SQL stands for Structured Query language, pronounced as "S-Q-L" or sometimes as "See-Quel"... Relational databases like MySQL Database, Oracle, MS SQL Server, Sybase, etc. use ANSI SQL.

What is a Database Management System (DBMS)?

Database Management System (DBMS) is a collection of programs which enables its users to access database, manipulate data, reporting and representation of data. It also helps to control access to the database. Database Management Systems are not a new concept and as such, had been first implemented in the 1960s.

Charles Bachman's Integrated Data Store (IDS) is said to be the first DBMS in history. With time database technologies evolved a lot while usage and expected functionalities of databases have been increased immensely.

Types of DBMS

Let us see how the DBMS family got evolved with time. The following diagram shows the evolution of DBMS categories.

There are 4 major types of DBMS. Let us investigate them in detail.

• Hierarchical: This type of DBMS employs the "parent-child" relationship of storing data. This type of DBMS is rarely used nowadays. Its structure is like a tree with nodes representing records and branches representing fields. The windows registry used in Windows XP is an example of a hierarchical database. Configuration settings are stored as tree structures with nodes.
• Network DBMS: This type of DBMS supports many-to-many relations. It usually results in complex database structures. RDM Server is an example of a database management system that implements the network model.
• Relational DBMS: This type of DBMS defines database relationships in the form of tables, also known as relations. Unlike network DBMS, RDBMS does not support many to many relationships. Relational DBMS usually have pre-defined data types that they can support. It is the most popular DBMS type in the market. Examples of relational database management systems include MySQL, Oracle, and Microsoft SQL Server database.
• Object-Oriented Relation DBMS: This type supports the storage of new data types. The data to be stored is in the form of objects. The objects to be stored in the database have attributes (i.e., gender, ager) and methods that define what to do with the data. PostgreSQL is an example of an object-oriented relational DBMS.

What is NoSQL?

NoSQL is an upcoming category of Database Management Systems. Its main characteristic is its non-adherence to Relational Database Concepts. NoSQL means "Not only SQL". The concept of NoSQL databases grew with internet giants such as Google, Facebook, Amazon etc. who deal with gigantic volumes of data.

When you use a relational database for massive volumes of data, the system starts getting slow in terms of response time. To overcome this, we could "scale up" our systems by upgrading our existing hardware. The alternative to the above problem would be to distribute our database load on multiple hosts as the load increases. This is known as "scaling out".

NoSQL database is non-relational databases that scale-out better than relational databases and are designed with web applications in mind. They do not use SQL to query the data and do not follow strict schemas like relational models. With NoSQL, ACID (Atomicity, Consistency, Isolation, Durability) features are not guaranteed always.