# Connect to a database with a username
psql <database_name> -U <user_name>

# List all databases
\l

# Connect to a database inside psql
\connect <database_name>

# List all tables in a database
\dt *.*

# Change username's password from psql# prompt after logging in
ALTER USER "<user_name>" WITH PASSWORD '<new_password>';

# Configure a jdbc connection from rubymine. Note: jdbc requires password
Host: localhost
Database: <database_name>
User: <user_name>
Password: <password>
Port: 5432