Forecast cashflow month over month based on historical trends by service

Postgres SQL, as run

select date_trunc('month', billing_period_start at time zone 'UTC') as billing_month,
       provider_name as provider_name,
       service_category as service_category,
       service_name as service_name,
       sum(billed_cost) as total_billed_cost
from focus.cost_and_usage
where billing_period_start >= $1::timestamptz
  and billing_period_end < $2::timestamptz
group by 1, 2, 3, 4
order by billing_month, total_billed_cost desc nulls last, provider_name, service_category nulls last, service_name nulls last
limit 500

Parameters: $1 = billing_period_start, $2 = billing_period_end

Original FOCUS SQL

SELECT
  MONTH(BillingPeriodStart),
  ProviderName,
  ServiceCategory,
  ServiceName,
  SUM(BilledCost) AS TotalBilledCost
FROM focus_data_table
WHERE BillingPeriodStart >= ? AND BillingPeriodEnd < ?
GROUP BY
  MONTH(BillingPeriodStart),
  ProviderName,
  ServiceCategory,
  ServiceName