Know your MongoDB

Hi All,

From past many weeks I had this eagerness to know what MongoDB is? & how it actually works. Brainstorming and learning lead to an inference that configuration is simple & easy, just follow some steps and start your journey in the new world.

So follow the trail to know what it actually is...


What is Mongo DB
A document based Database that stores Data in JSON Format. The fields can vary from document to document & YES its FREE and OPEN SOURCE.


Pros

• Dynamic : There is no defined schema so your collection and its document can be of user's choice,  style & need.
• No Joins required that makes it simple and easy to use
• Flexible : Fields addition, updation is super easy and has less/no impact on he Application
• Easy Integration & Configuration
• It is document based & highly powerful
• Cloud storage and distribution is key feature
• High performance

Cons

• Not perfectly ACID compliant
• No stored procedure.
• No auto-increment default option however can be achieved using Javascript code logic

Configuration

• Download from https://www.mongodb.com/download-center
• Alternative way to install using Homebrew as $ brew install mongodb 
• You can configure  on local as well as remote machine
• From 3.6 version of mongodb both mongod and mongos binaries are by default bind to LocalHost
• Open your terminal
• Unzip the downloaded TAR in a folder named Mongo
• $ cd Mongo
• $ tar-zxvf mongodb-osx-ssl-x86_64-4.0.3.tgz
• Move
• $ sudo mv mongodb-osx-ssl-x86_64-4.0.3 /usr/local/mongodb
• Create a folder where Mongodb can store/write data, by default location is /data/db which needs to be created manually with proper permissions
• $ sudo mkdir -p /data/db
• $ sudo chown [LOGGED_IN_USER] /data/db
• The default location can also be changed using 
• $ mongod --dbpath /your_directory
• To access mongodb commands you have to create a ~/.bash_profile file & assign /usr/local/mongodb/bin to $PATH environment variable
• $ cd ~
• $ pwd /users/[LOGGED_IN_USER]
• $ touch .bash_profile
• $ open .bash_profile 
• Above command opens a text editor, paste below 2 commands in there and save
• export MONGO_PATH=/usr/local/mongodb
• export PATH=$PATH:$MONGO_PATH/bin
• Restart the terminal 
• $ mongo -version
• $ mongod 
• above command start the mongo daemon
• Open another terminal window
• $ mongo
• Now in this terminal window you will see 

      MongoDB server version: 4.0.3

      Welcome to the MongoDB shell

What is Mongo

• This is a JS shell interface for MongoDB which access the database

What is MongoD

• This is a daemon, a host process for the database which runs mongodb process in background.
• This has several default params associated with it
• It runs on port 27017
• Stores data in /data/db

What is bash profile & its usage in MongoDB

• Its a hidden file that loads before the Terminal loads the shell environment
• It contains shell configurations and preferences.
• MongoDB paths are set in this file

Difference between SQL and Mongodb

Sql Server	MongoDB
Database	Database
Table	Collection
Index	Index
Row	Document
Column	Field
Joins	Link
Partition	Range Partition