Optimize SQL query to select countries with GDP exceeding Europe's maximum

[Imran-imtiaz48]

The query optimizes the selection process by first determining Europe's maximum GDP in a subquery. This result (max_gdp) is then used to filter countries in the main query, ensuring that only countries with GDP values higher than Europe's highest GDP are returned. This approach avoids redundant calculations and improves query efficiency by leveraging a subquery result directly in the main query's filtering condition.