Data Modelling Study Portal

TL;DR

"SQL or NoSQL" is the wrong framing, and answering it as a preference is the fastest way to look junior. The real question is what your access patterns are, because that determines everything: a relational database is the correct default because it lets you query data you did not anticipate, and you move away from it when a specific, known access pattern outgrows what one machine can serve. Indexes are the other half of the story — they are what make a query fast, they cost write throughput and storage, and the single most common production surprise is a query that ignores the index you built because of how the predicate was written.