RDBMS(SQL) Vs NOSQL

Gaining knowledge in both Relational Database Management Systems (RDBMS) and NoSQL databases requires a structured approach that balances theory with hands-on practice. Here's a roadmap to help you:

1. Learn the Fundamentals

RDBMS Concepts: ACID properties, normalization, SQL queries, indexing, transactions.
NoSQL Concepts: BASE properties, CAP theorem, eventual consistency, different NoSQL types (document, key-value, column-family, graph).

Resources:
Courses: Udemy, Coursera, Khan Academy, or YouTube tutorials on databases.
Official Documentation: PostgreSQL, MySQL, MongoDB, etc.

2. Learn RDBMS First (SQL Databases)

Start with at least one RDBMS, preferably PostgreSQL or MySQL, as they are widely used and open-source.

Practice SQL:
Create tables, relationships, and indexes.
Perform CRUD operations (SELECT, INSERT, UPDATE, DELETE).
Write complex queries with JOIN, GROUP BY, HAVING, CTEs.
Learn stored procedures and triggers.

Hands-on Practice:
Set up PostgreSQL/MySQL on your system or use cloud-based databases like AWS RDS, Google Cloud SQL.
Use DBMS tools like pgAdmin, MySQL Workbench.
Solve SQL problems on platforms like LeetCode, HackerRank, Mode Analytics.

3. Explore NoSQL Databases

Since NoSQL has multiple types, focus on one from each category:

NoSQL Type Example Databases Best For   Document MongoDB, CouchDB JSON-like data, flexible schema  Key-Value Redis, DynamoDB Caching, real-time analytics  Column-Family Cassandra, HBase Big Data, distributed storage  Graph Neo4j, ArangoDB Social networks, relationship-heavy data

Practice:
Learn MongoDB first (document database) by creating collections, inserting documents, and querying with the aggregation pipeline.
Set up Redis for caching and session storage.
Work with Cassandra or Neo4j if you're dealing with large-scale data or graph-based applications.

Resources:
MongoDB University (Free Courses).
Redis tutorials on their official website.
Neo4j Graph Academy for graph databases.

4. Compare RDBMS vs NoSQL with Real-World Scenarios

Work on real projects where you can use both databases:
Use PostgreSQL for transactional data and MongoDB for unstructured product catalogs.
Store user sessions in Redis while keeping relational user data in MySQL.
Implement a recommendation system using Neo4j.

5. Work on Hands-on Projects

Building projects will solidify your knowledge. Try these:
E-commerce App: PostgreSQL (orders) + MongoDB (product catalog) + Redis (session cache).
Chat Application: Firebase (real-time messaging) + PostgreSQL (user profiles).
Log Analysis: Store logs in Cassandra for high availability and run analytics on them.

6. Learn Database Optimization & Scaling

Indexing and Query Optimization (EXPLAIN ANALYZE in PostgreSQL).
Database Partitioning and Sharding (Cassandra, MongoDB, MySQL).
Replication and High Availability (Master-Slave, Read Replicas).
Use Docker and Kubernetes for database containerization and orchestration.