Dian said it all.
I would like to add that after you designed your models, tables and relations and eventually used JSON for "non structured data" you might want to use full text search.
Consider PostgreSQL's own FTS before diving into elastic search or others: rachbelaid.com/postgres-full-text-...
Also since PostgreSQL 10 you have FTS on JSON columns: wiki.postgresql.org/wiki/New_in_po...
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.