Query: rds_db_instance_cost_per_month

select
  to_char(period_start, 'Mon-YY') as "Month",
  sum(unblended_cost_amount)::numeric as "Unblended Cost"
from
  aws_cost_by_service_usage_type_monthly
where
  service = 'Amazon Relational Database Service'
  and usage_type like '%Instance%'
group by
  period_start
order by
  period_start;