It is good practice for Engineering to monitor cost and usage of services by availability zone for all regions to ensure:
SELECT ProviderName, RegionName, AvailabilityZone, BillingPeriodStart, SUM(EffectiveCost) AS TotalEffectiveCost FROM focus_data_table WHERE SubAccountId = ? AND ChargePeriodStart >= ? AND ChargePeriodEnd < ? GROUP BY ProviderName, RegionName, AvailabilityZone, BillingPeriodStart ORDER BY ProviderName, RegionName, AvailabilityZone, BillingPeriodStart