Types of Databases

There are several types of databases, each with its strengths and weaknesses. Some common types include:

• Relational databases (e.g. MySQL, PostgreSQL) - These databases store data in tables with rows and columns and use SQL (Structured Query Language) for querying and manipulating the data. They are best for structured data and are commonly used for transactional systems and online applications. Here are some of the resources to get started with RDBMS, https://sqlbolt.com/, https://www.w3schools.com/sql/default.asp, https://mode.com/sql-tutorial/
• NoSQL databases (e.g. MongoDB, Cassandra) - These databases do not use a fixed schema and can handle unstructured and semi-structured data. They are best for high scalability and performance and are often used for big data and real-time web applications. https://learn.mongodb.com/ has free resources to get started with MongoDB.
• Graph databases (e.g. Neo4j) - These databases are optimized for storing and querying data with complex relationships. They are best for data with many-to-many relationships and are often used in recommendation systems and social networks. https://graphacademy.neo4j.com/, the official Graph database website, offer free tutorials on getting started with Graph databases, Cypher query language, and real-world use cases.
• Time-series databases (e.g. InfluxDB) are optimized for storing and querying time-series data, such as sensor data, financial data, and log data. They are best for monitoring and analytics use cases and IoT. https://www.influxdata.com/university/, the official website of Time-series databases, offers free tutorials on getting started with Time-series databases, InfluxQL, and real-world use cases.
• In-memory databases (e.g. Redis, Memcached) - These databases store data in RAM for fast access. They are best for real-time data processing and caching and are often used for sessions, leaderboards, and other performance-critical data. https://redis.io/docs/getting-started/ is an excellent resource to get started with Redis.

When you choose a database, it's essential to consider the specific needs of your application and the type of data you'll be working with. Relational databases are often the best choice for structured data, while NoSQL databases are better for unstructured data. Graph databases are well-suited for highly connected data, and in-memory databases are great for real-time data processing.