Which scenario is best suited for a NoSQL database?

• A. Highly structured data with complex SQL queries
• B. Very small datasets that fit in memory
• C. Large volumes of unstructured or rapidly changing data requiring horizontal scalability
• D. Systems requiring strict ACID transactions across many tables

Answer: (C)

NoSQL databases thrive when you’re dealing with very large volumes of unstructured or rapidly changing data and need to scale out across many machines. They use flexible, schema-less data models and distribute data across a cluster, which supports horizontal growth and high throughput. In this scenario, that combination fits perfectly because the data isn’t neatly structured and the workload benefits from adding more servers rather than upgrading a single machine.

The other options don’t fit as well: highly structured data with complex SQL queries is a strong match for relational databases that support joins and ACID transactions; very small datasets that fit in memory don’t require distributed, scalable storage; systems needing strict ACID across many tables align more with relational databases (or NewSQL) than with typical NoSQL setups.