MongoDB - NOSQL Database

MongoDB is a document-oriented NoSQL database used for high-volume data storage. Instead of using tables and rows as in relational databases, MongoDB uses collections and documents.

Key Features of MongoDB

1. Schema-less – No fixed structure, allowing flexibility.

2. Scalability – Horizontally scalable using sharding.

3. High Performance – Fast read and write operations.

4. Replication – Provides high availability using replica sets.

5. Indexing – Supports different types of indexes to improve query performance.

6. Aggregation Framework – Enables complex data transformations.

MongoDB Architecture

MongoDB follows a distributed architecture with multiple components:

1. Client – Applications interact with MongoDB using drivers.

2. MongoDB Server – Stores and manages the data.

3. Replica Set – Ensures fault tolerance and high availability.

4. Sharded Cluster – Enables horizontal scaling for large datasets.

5. Config Servers – Store metadata for sharded clusters.

6. Mongos Router – Distributes queries across shards.

Basic MongoDB Operations

1. Creating a Database

use myDatabase;

1. Creating a Collection

db.createCollection("users");

1. Inserting a Document

db.users.insertOne({
    name: "John Doe",
    email: "[e-mail]",
    age: 28,
    created_at: new Date()
});

1. Finding Documents

db.users.find({ age: { $gt: 25 } });

1. Updating a Document

db.users.updateOne(
    { email: "[e-mail]" },
    { $set: { age: 30 } }
);

1. Deleting a Document

db.users.deleteOne({ email: "[e-mail]" });

MongoDB Use Cases

• Big Data Applications

• Real-time Analytics

• Internet of Things (IoT)

• Content Management Systems

• Mobile and Web Apps