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How to Optimize Database Queries

Posted by Alice on Sep 16, 2025 • 42 views

Hello everyone,

I'm working on a legacy MySQL application and some queries have become painfully slow after recent data growth. I've tried adding indexes, but the performance is still not where it should be. Could anyone share strategies, tools, or best practices for profiling and optimizing complex queries?

Thanks in advance!

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Bob • Sep 16, 2025 at 11:05 AM

First, enable the slow_query_log and set long_query_time to something reasonable (e.g., 0.5s). This will give you the exact queries that need attention.

Cara • Sep 16, 2025 at 12:20 PM

Consider using EXPLAIN ANALYZE (MySQL 8+) to see the actual execution time for each step. It often reveals hidden bottlenecks like temporary tables or filesorts.