I’m versed enough in SQL and RDBMS that I can put things in the third normal form with relative ease. But the meta seems to be NoSQL. Backends often don’t even provide a SQL interface.

So, as far as I know, NoSQL is essentially a collection of files, usually JSON, paired with some querying capacity.

1. What problem is it trying to solve?
2. What advantages over traditional RDBMS?
3. Where are its weaknesses?
4. Can I make queries with complex WHERE clauses?