Fwd: Want to acquire lock on tables where primary of one table is foreign key on othere

[Abhishek Tripathi <postforabhishek@xxxxxxxxx>]

---------- Forwarded message ---------
From: Abhishek Tripathi <postforabhishek@xxxxxxxxx>
Date: Thu, Oct 11, 2018 at 3:18 PM
Subject: Want to acquire lock on tables where primary of one table is foreign key on othere
To: <pgsql-bugs@xxxxxxxxxxxxxxxxxxxx>

Dear Concerned Person,

 I write this email to get the information about locking which I am not getting from anywhere.

Actually I have acquired a "Select for Update" on a table whose id is refrence as a foreign key on another table So I want those table won't update until there is lock. Is it possible? Becuase postgres is acquiring lock but AccessShare Lock which allow to write on those table How I restrict this.

Thanks and Regards 

Abhishek