When executing your SQL query, if you notice a performance issue, how will you address it?

When I notice a performance issue during query execution, I first run EXPLAIN to see the execution plan. I look for expensive operations like full scans or large shuffle joins. I then check if the tables are properly indexed or partitioned and whether the query can benefit from materialized views. If the query is join‑heavy, I consider rewriting it to use semi‑joins or broadcast joins. I also profile the query on a smaller dataset to isolate the slow part. After applying optimizations, I re‑run the query and compare the execution time. If performance is still sub‑optimal, I may involve the database administrator to tune configuration parameters or add hardware resources.