What does the following demonstrate about the EXISTS vs IN performance trade-off? — Query A: WHERE id IN (SELECT customer_id FROM orders WHERE total > 1000) — Query B: WHERE EXISTS (SELECT 1 FROM orders o WHERE o.customer_id = c.id AND o.total > 1000)

Key points

• EXISTS stops processing after finding a match, while IN evaluates the entire subquery.
• IN is generally slower when the subquery returns many rows.
• Understanding this trade-off is crucial for optimizing SQL queries.