How do you optimize a query on a very large database?
Assume the query must summarize completed vehicle sales from the supplied tables for calendar year 2025. Write PostgreSQL SQL that returns the requested result efficiently.
region, model_name, units_sold, and total_revenue.| Column | Type | Description |
|---|---|---|
| sale_idPK | INT | Unique sale identifier |
| dealer_id | INT | Dealer associated with the sale |
| model_id | INT | Vehicle model sold |
| sold_at | DATE | Sale date |
| sale_status | VARCHAR(20) | Sale lifecycle status |
| sale_price | NUMERIC(12,2) | Sale amount |
| Column | Type | Description |
|---|---|---|
| dealer_idPK | INT | Unique dealer identifier |
| dealer_name | VARCHAR(100) | Dealer name |
| region | VARCHAR(40) | Sales region |
| Column | Type | Description |
|---|---|---|
| model_idPK | INT | Unique model identifier |
| model_name | VARCHAR(80) | Vehicle model name |
| vehicle_type | VARCHAR(40) | Vehicle classification |