MongoDB: An introduction

MongoDB is the most popular open-source, document-oriented NoSQL database, holding over 45% of the NoSQL market share. Unlike relational databases that rely on rigid tables, MongoDB stores data in a flexible BSON format (similar to JSON), enabling faster and more efficient storage and retrieval.

• SQL databases store data in tabular format. These data are stored in a predefined data model, which is not flexible for rapidly growing applications in today's real world.
  
• Modern applications are more social, interactive, and networked than ever. Applications store more and more data and access it at higher rates.
  
• Relational Database Management Systems are not the correct choice when it comes to handling big data by the virtue of their design, since they are not horizontally scalable. If the database runs on a single server, then it will reach a scaling limit.
  
• NoSQL databases are more scalable and provide superior performance. MongoDB scales by adding more and more servers and increases productivity with its flexible document model.

A simple MongoDB document Structure: 

{
  title: 'Geeksforgeeks',
  by: 'Mahima Bhardwaj,'
  url: 'https://www.geeksforgeeks.org/',
  type: 'NoSQL'
}

Note: Unlike relational databases, MongoDB does not require a fixed schema, make it easier to adapt to changing application needs.

Features of the MongoDB database

• Document Oriented: MongoDB stores the main subject in the minimal number of documents and not by breaking it into multiple relational structures like RDBMS. For example, it stores all the information of a computer in a single document called Computer and not in distinct relational structures like CPU, RAM, Hard disk, etc.
  
• Indexing: Without indexing, a database would have to scan every document of a collection to select those that match the query, which would be inefficient. So, for efficient searching, Indexing is a must, and MongoDB uses it to process huge volumes of data in very little time.
  
• Scalability: MongoDB scales horizontally using sharding (partitioning data across various servers). Data is partitioned into data chunks using the shard, and these data chunks are evenly distributed across shards that reside across many physical servers. Also, new machines can be added to a running database.
  
• Replication and High Availability: MongoDB increases data availability with multiple copies of data on different servers. By providing redundancy, it protects the database from hardware failures. If one server goes down, the data can be retrieved easily from other active servers that also have the data stored on them.
  
• Aggregation: Aggregation operations process data records and return the computed results. It is similar to the GROUPBY clause in SQL. A few aggregation expressions are sum, avg, min, max, etc.

Where do we use MongoDB?

MongoDB is preferred over RDBMS in the following scenarios:

• Big Data: If we have a huge amount of data to be stored in tables, think of MongoDB before RDBMS databases. MongoDB has a built-in solution for partitioning and sharding our database.
• Unstable Schema: Adding a new column in RDBMS is hard, whereas MongoDB is schema-less. Adding a new field does not affect old documents and will be very easy.
• Distributed data. Since multiple copies of data are stored across different servers, recovery of data is instant and safe even if there is a hardware failure
• IOT Applications: Collecting and processing sensor data.
• Content Management System: storing varied content structures.
• Real Time Analytics: Processing large datasts quickly
• E-commerce Platforms: Product catalogs with different attributes
• Social Media Applications: Handling user post, comments, likes etc.

Language Support by MongoDB

MongoDB currently provides official driver support for all popular programming languages like C, C++, Rust, C#, Java, Node.js, Perl, PHP, Python, Ruby, Scala, Go and Erlang.

How to Install MongoDB

Just go to https://www.mongodb.com/try and select your operating system out of Windows, Linux, Mac OS X and Solaris. A detailed explanation about the installation is provided.

For Windows, a few options for the 64-bit operating systems drops down. When you are running on Windows 7, 8 or newer versions, select Windows 64-bit 2008 R2+. When you are using Windows XP or Vista then select Windows 64-bit 2008 R2+ legacy.