Flipkart interview | sde-2 | design relational database system like application | round3

hi folks,
i had given this Flipkart interview round -3 | system design round .

problem : design relational database like application for ex :- mysql, postgres.

please write down :-
function req.
non functional req
entities relationship
component design

mainly focus on efficient read and write operations.

please suggest solution, any resources , solution for the same.
thanks