Write a query to find the top three most-used cloud services by region, utilizing window functions on Google Cloud usage data. Treat usage_units as the usage measure and sum it for each service within each non-null region. Include only services that match the service catalog.
region, service_name, total_usage, and usage_rank.| Column | Type | Description |
|---|---|---|
| service_idPK | INT | Unique identifier for a Google Cloud service |
| service_name | VARCHAR(100) | Google Cloud service name |
| Column | Type | Description |
|---|---|---|
| usage_idPK | INT | Unique usage record identifier |
| region | VARCHAR(50) | Google Cloud region where usage occurred |
| service_id | INT | Referenced Google Cloud service identifier |
| usage_units | BIGINT | Measured usage for the record |