What is MongoDB

What is MongoDB:

MongoGB is a free and open source cross-platform document-oriented program.

Classified as a NoSQL Database Program, MongoDB uses JSON-like documents with schema. MongoDB is developed by MongoDB Inc.

{

  "_id": "5cf0029caff5056591b0ce7d",

  "firstname": "Sudipt",

  "lastname": "Sahu",

  "address": {

                              "street": "VIP Road",

                              "city": "kolkata",

                              "state": "WB",

                              "zip": "700091"

                   },

  "hobbies": ["surfing", "coding"]

}

MongoDB stores data in flexible, JSON-like documents, meaning fields can vary from document to document and data structure can be changed over time MongoDB is a distributed database at its core, so high availability, horizontal scaling, and geographic distribution are built in and easy to use

Ad hoc queries, indexing, and real time aggregation provide powerful ways to access and analyze your data

What is JSON

JavaScript Object Notation (JSON) is an open, human and machine-readable standard that facilitates data interchange, and along with XML is the main format for data interchange used on the modern web. JSON supports all the basic data types you’d expect: numbers, strings, and Boolean values, as well as arrays and hashes.

Document databases such as MongoDB use JSON documents in order to store records, just as tables and rows store records in a relational database. 

What Is BSON

The name “BSON” is based on the term JSON and stands for “Binary JSON”. MongoDB represents JSON documents in binary-encoded format called BSON behind the scenes

Programming Language for MongoDB

MongoDB has official drivers for major programming languages and development environments.

Ø  PHP

Ø  Python

Ø  Java

Ø  Node.Js – Not a PL , it’s a run time environment for Java Script

Ø  C++

Ø  C#

Software used

The primary interface to the database has been the mongo shell. Since MongoDB 3.2, MongoDB Compass is introduced as the native GUI. There are products and third-party projects that offer user interfaces for administration and data viewing

Ø  mongoDb community server Database

Ø  Robo 3T (RoboMongo) – GUI Tool to operate MongoDB

3 versions available for MongoDB

1. MongoDB Atlas - MongoDB is also available as an on-demand fully managed service. MongoDB Atlas runs on AWS, Microsoft Azure, and Google Cloud Platform
2. MongoDB Enterprise Server - MongoDB Enterprise Server is the commercial edition of MongoDB, available as part of the MongoDB Enterprise Advanced subscription
3. MongoDB Community Server - The MongoDB Community Edition is free and available for Windows, Linux, and OS X

 

Difference between MongoDB & RDBMS

Below are some of the key term differences between MongoDB and RDBMS

Database – Database is a physical container for collections. Each database gets its own set of file system. A single MongoDB server typically has multiple databases.

Collection – collection is a group of MongoDB documents. It is the equivalent of an RDBMS table. A collection exists within a single database. Collection do not enforce schema. Documents within a collection can have different fields. Typically, all documents in a collection are of similar or related purpose.

RDBMS	Definition	MongoDB	Definition
Database		Database
Table	Table contains the columns and rows which are used to store the data	Collection	collection is a group of MongoDB documents. It is the equivalent of an RDBMS table. A collection exists within a single database. Collection do not enforce schema. Documents within a collection can have different fields. all documents in a collection are of similar or related purpose
Row		Document	A document is a set of key-value pair. Documents have dynamic schema. Collection do not need to have the same set of fields or structure, and common fields  in a collection documents may hold different types of data.
Column		Field	Key in MongoDB.
Join	To get the data from different tables sometimes we need to perform Joins	Embedded Document, $lookup	No any concept of Join in MongoDB. In MongoDB, the data is normally stored in a single collection, but separated by using Embedded documents
Index		Index
Primary key	Specify any unique column or column combination as primary key.	Primary key	In MongoDB, the primary key is automatically set to the _id field.

RDBMS (Structure) VS. MongoDB (Structure)

How MongoDB Makes it Easy

·        Documents. Using MongoDB’s document model, you can incorporate any type of data, no matter what it looks like or where it comes from. JSON documents support all the basic data types you’d expect (e.g., numbers, strings, binary data, arrays) without requiring you to define or enforce a schema.

·        Dynamic Schemas. Schemas in MongoDB are self-describing. Iterate on the schema without having to rethink it entirely. Pull in new data when you need to. MongoDB documents can also vary in structure, which means documents from one system don’t need to have all the same fields as documents from another.

·        MongoDB’s expressive query language, indexing, and aggregation capabilities make it possible to find and filter the data, no matter how the business needs to access it.

Main Features of MongoDB?

Ø  Ad hoc queries - MongoDB supports field, range query, and regular expression searches

Ø  Indexing - Fields in a MongoDB document can be indexed with primary and secondary indices. Indexes support the efficient execution of queries in MongoDB. Without indexes, MongoDB must perform a collection scan, i.e. scan every document in a collection, to select those documents that match the query statement.

Ø  Replication - MongoDB provides high availability with replica sets. A replica set consists of two or more copies of the data. Each replica set member may act in the role of primary or secondary replica at any time. All writes and reads are done on the primary replica by default. Secondary replicas maintain a copy of the data of the primary using built-in replication. When a primary replica fails, the replica set automatically conducts an election process to determine which secondary should become the primary. Secondaries can optionally serve read operations, but that data is only eventually consistent by default.

Ø  Load balancing - MongoDB uses the concept of sharding to scale horizontally by splitting data across multiple MongoDB instances. MongoDB can run over multiple servers, balancing the load and/or duplicating data to keep the system up and running in case of hardware failure.

Ø  File storage - MongoDB can be used as a file system, called GridFS, with load balancing and data replication features over multiple machines for storing files.

Ø  Aggregation - MongoDB provides three ways to perform aggregation: the aggregation pipeline, the map-reduce function, and single-purpose aggregation methods.