Almost all the data is stored in databases. Broadly databases are of two types:
- Relational (SQL): Structured data with predefined schemas (e.g., MySQL, PostgreSQL).
- NoSQL: Unstructured or semi-structured data (e.g., MongoDB, DynamoDB).
Choosing the correct database system is one of the most difficult task. We need to have an clear idea of what the requirements are today and what might be tomorrow. We need to fore see things. Migrating from one database system can be done but brings massive cost and risk.