Adding random indexes to a slow query rarely fixes the root cause and can increase write costs. Start with the actual execution plan, row estimates and wait events.
A useful index follows filtering and ordering patterns without carrying unnecessary columns. Oracle execution plans, AWR and lock waits should be evaluated alongside MySQL EXPLAIN ANALYZE, slow query logs and buffer usage.
Performance is continuous: monitor query latency, resource use and data growth, remove unused indexes and keep statistics current.
Correct Indexing for Database Performance
