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optimizer_hints_and_plans

🛠️ Guide the Planner with Hints and Analyze Plans​

When the optimizer misestimates, hints or plan guides can force desired execution paths. In SQL Server use OPTION (FORCE ORDER), or in Oracle use /*+ INDEX(table idx_name) */. Always validate with EXPLAIN.

-- SQL Server hint example
SELECT *
FROM orders o
JOIN customers c ON o.customer_id = c.id
OPTION (HASH JOIN, MAXDOP 1);

-- PostgreSQL plan analysis:
EXPLAIN (ANALYZE, VERBOSE)
SELECT * FROM orders WHERE status = 'pending';