restore compressed dump query in postgresql asks password
Find the postgresql installation folder containing pg_hba.conf. Edit the authentication chapter at the end of this file, adding 

local   all         all                               trust
host    all         all         127.0.0.1/32          trust
host    all         all         ::1/128               trust


and restart. After that postgresql should not ask for the password to authenticate into any account if this is done from the same machine where the postgresql server is running.

Afterwards, change passwords to be sure you know them. Finally, remove the added lines from pg_hba.conf for more security. You can only bypass authentication because you already have root rights on that computer.