touch `date +%F-%I-%M-%S`-filanme.sql
# Recommend
touch `date +%s`-filanme.sql
# Backup with postgres
pg_dump -U [user] [dbname] > ./postgresql/`date +%s`_backup_[dbname].sql
# example
pg_dump -U postgres demo > ./postgresql/`date +%s`_backup_demo.sql