Notes postgre :

Find the file pg_hba.conf - it may be located, for example in /etc/postgresql-9.1/pg_hba.conf.or ./data/pg_hba.conf
Back it up

cp pg_hba.conf pg_hba.conf-backup

Authorize local user to connect directly place the following line (as either the first uncommented line, or as the only one):

local  all   all   trust

Restart database

Connect to postgres schema : (you can now connect as any user). Connect as the superuser postgres (note, the superuser name may be different in your installation. In some systems it is called pgsql, for example.)

psql -U postgres 

#Note for AXA : psql -U aopuser postgres
#Note for HPA : psql -U hpa -p hpadb

Reset password ('replace my_user_name with postgres since you are resetting postgres user)

ALTER USER my_user_name with password 'my_secure_password';

Restore the old pg_hba.conf as it is very dangerous to keep around, restart?