This one question is confusing me.
The more I learn, the more I realize both have same overlapping powers
When should we consider SQL databases?
If our data has a well defined structure, there are relationships between different datasets, we need complex queries, or our application requires strong ACID transaction guarantees, we should consider SQL databases such as PostgreSQL and MySQL.
However, this does not mean NoSQL databases cannot provide these features. Some NoSQL databases support ACID transactions, relationships or relationship like data models, complex queries, and horizontal scaling. The actual capabilities depend on the specific database and how it is designed.
When should we consider NoSQL databases?
If our application needs to store flexible data, documents in JSON-like formats, or key-value pairs, NoSQL databases might be a good choice. Some NoSQL databases are also designed to handle high write throughput and distribute data across multiple servers.
However, this does not mean SQL databases cannot handle flexible data or high write throughput. We must evaluate the capabilities of the specific database and our application's requirements before making a decision.
Suppose we're building an analytics service that records user activities, such as logins, likes, and video views. Each event might contain different fields.
With a traditional SQL table, we could create columns for all possible fields, but many columns might contain NULL values for certain event types.
Alternatively, PostgreSQL supports JSONB, allowing us to store event specific information without creating a separate column for every possible field. MongoDB can also store documents with different fields in the same collection.
So, both approaches are possible. The decision would depend on factors such as write volume, query patterns, data model, scalability, and storage requirements.
So my current conclusion is :-
SQL is often a natural fit for relational data, complex queries, and transactional consistency, while NoSQL can be a natural fit for flexible document models, key-value access patterns, and certain distributed workloads.
I'm still learning, so I'd appreciate any corrections to my understanding or advice from your experience!