Database optimizer chooses join order based on statistics. Usually optimal, but sometimes needs hints. Join order can dramatically affect performance.

Optimizer considers table sizes, indexes, statistics. Typically joins smaller tables first. You can influence with subqueries, CTEs, or hints. Always test with EXPLAIN.

Join order optimization is essential for performance tuning. Senior developers must understand query optimization and execution plans.

Complex reports with 5-10 table joins need optimization. Understanding join order helps debug slow queries. Critical for data warehouse and analytics queries.