resetting postgres database

a.rb

find the file pg_hba.conf - it may be located, for example in /etc/postgresql-9.1/pg_hba.conf.

cd /etc/postgresql-9.1/

Back it up

cp pg_hba.conf pg_hba.conf-backup

place the following line (as either the first uncommented line, or as the only one):

local  all   all   trust

restart your PostgreSQL server (e.g., on Linux:)

sudo /etc/init.d/postgresql restart

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

Reset password

ALTER USER my_user_name with password 'my_secure_password';

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

cp pg_hba.conf-backup pg_hba.conf

restart the server, in order to run with the safe pg_hba.conf

sudo /etc/init.d/postgresql restart

Further Reading about that pg_hba file: http://www.postgresql.org/docs/9.1/static/auth-pg-hba-conf.html