a guy give me his ver.14 test database for learning purpose. he says he forgot the password. i restored the database. i tried below before asking here but failed to get success.  off course i have no idea how i can reset / modify the password to connect. 

sudo su postgres

psql

\c odb

You are now connected to database "odb" as user "postgres". 

\du -- this shows only default database users  not for odb to list the users which require to reset/modify password

select u.partner_id, p.name from res_users u, res_partner p where u.partner_id = p.id;

this sql also returns the default database's data (like above \du) as odb contains some other users too. 

this require to (also) modify a user's password in table res_users OR res_partner to login that app.

hope i have cleared all things and will have some experts reply and guidance.