> O(1) Primary key fetching will always be O(log n) due to how indexes are implemented. Access time complexity will never be independent of the item count in y

> O(1) Primary key fetching will always be O(log n) due to how indexes are implemented. Access time complexity will never be independent of the item count in your data store, relational or not. > PostgreSQL's JSON type is not relational. It is. In Postgres, you can join nested JSON structures' keys with normal, relational tables: https://dba.stackexchange.com/questions/83932/postgresql-joining-using-jsonb https://dba.stackexchange.com/questions/83932/postgresql-joi... My point is: Postgres offers you a document store and gives you the option to join, if you feel like it.