NoSQL Databases Overview

Study Notes

NoSQL (non-relational databases) are designed for storing, retrieving, and managing non-tabular data.
They have a schema-less or flexible schema.
They handle various data types: structured, semi-structured (JSON), and unstructured (text, images, logs).
They are horizontally scalable.

When scalability is needed (easily handle large data volumes).
When flexibility is needed (dynamic schema design allows for quick iterations and changes).
When performance is important (optimized for specific data models and access patterns).
For Big Data and Real-Time Applications.

Used for content management systems (e.g., storing website documents).
Documents within a collection can have different fields/structures.
No strict schema enforcement, allowing diverse data formats.
Useful when storing products with varying attributes based on categories.
Example use case: A news website uses MongoDB to store articles with fields like title, body, author, tags, and publication date.
Flexible schema allows for adding new fields (e.g., multimedia content) without altering existing documents.
Can handle millions of users by distributing load across multiple servers.

Used for caching mechanisms, session management, and real-time bidding.
Example use case: Online shopping platform uses Redis to manage user sessions.
Each user session is stored with a unique session ID (key) and session data (cart contents, etc) as its value
Fast access and updates to session information.

Designed to efficiently store, manage, and query highly interconnected data.
Data are modeled as nodes (entities) connected by relationships (edges).
Particularly suitable for scenarios where relationships between data points are important.
Examples of usage include: social networks, recommendation systems, network and IT operations, and fraud detection.
Use case: social media platform uses Neo4j to manage and analyze social graphs; users as nodes, connections as edges.
Efficient for querying/analyzing connections, recommend friends, identifying influencers, and detecting fraud.

Neo4j Database: core product in community and enterprise versions.
Suitable for modeling, storing and querying interconnected data efficiently.
Neo4j Aura: fully managed cloud service for deploying and running Neo4j databases.
Offers scalability, security, and reliability in the cloud.
Other products may include desktop applications (like Neo4j Desktop) for development, or graph visualization tools (like Neo4j Bloom).

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