Senior Xiao Ying

Feb 22, 2026 · Databases

Why Is Your SQL Slow? Deep Dive into Common MySQL Slow Query Patterns and Optimizations

This guide explains how to configure MySQL's slow query log, use pt‑query‑digest to analyze logs, identifies common slow‑query patterns such as full table scans, large sorts, N+1 queries, implicit type conversion and bad joins, and provides concrete rewrite and indexing techniques to optimize each case.