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Level 6 - ExpertOptimization Questionsm2 performance schema

Optimization: EXISTS vs DISTINCT JOIN

Select the query that avoids duplicate explosion for existence check. Query A: SELECT DISTINCT c.id FROM customers c JOIN orders o ON c.id = o.customer_id WHERE o.status = 'PAID'; Query B: SELECT c.id FROM customers c WHERE EXISTS (SELECT 1 FROM orders o WHERE o.customer_id = c.id AND o.status = 'PAID');