Backup PostgreSQL database to a local file and retrieve it

create.txt

# create a bakup:

sudo su - postgres
pg_dump postgres > postgres_db.bak

# options:
pg_dump -U user_name -h remote_host -p remote_port name_of_database > name_of_backup_file

retrieve.txt

# Retrieve a backup
psql empty_database < backup_file
# Note: this redirection operation does not create the database in question. 
# This must be done in a separate step prior to running the command.