How do SQL developers optimize query performance for high-traffic applications?

SQL developers improve the performance of queries in heavy-traffic applications by honing queries, indexing with strategy, and minimizing the resource-costly operations. They use indexes to accelerate data retrieval but need to balance these so that they do not slow down the write operation. Query optimization includes rewriting huge and complex queries to reduce processing time and employing caching for frequently accessed data. They analyze the execution plans for bottlenecks and then make necessary adjustments to queries. SQL developers also ensure that databases do not collapse due to high volumes of traffic by taking measures such as partitioning large tables and creating efficient joins.