Write a query to find the top 3 performing regions by sales volume.
Use the provided regions and sales tables. Treat sales volume as the number of rows with a sale_status of completed; exclude sales that do not map to a named region.
region_name and sales_volume| Column | Type | Description |
|---|---|---|
| region_idPK | INTEGER | Unique identifier for a region |
| region_name | VARCHAR(50) | Display name of the region |
| Column | Type | Description |
|---|---|---|
| sale_idPK | INTEGER | Unique identifier for a sale |
| region_id | INTEGER | Region associated with the sale |
| sale_status | VARCHAR(20) | Current status of the sale |
| sale_date | DATE | Date on which the sale was recorded |