.pgpass is a common way to store connection information in PostgreSQL instead of typing password every time your login to your database using psql.
host:port:db_name:user_name:password Example: localhost:5432:postgres:myadmin:Str0ngP@ssw0rd
`nano ~/.pgpass
127.0.0.1:5432:*:username:password
chmod 0600 ~/.pgpass`
##Crontab 55 2 * * * /home/ubuntu/backup/backup-postgres.sh >> /tmp/myjob.log 2>&1