원문 https://dzone.com/articles/how-to-optimize-mysql-queries-for-speed-and-perfor How to Optimize MySQL Queries for Speed and Performance on Alibaba Cloud ECS In this guide, we will take you through the steps of optimizing SQL queries and databases on your Alibaba Cloud ECS instance running Ubuntu 16.04. www.alibabacloud.com 1. Index All Columns Used in 'where', 'order by', and 'group by' Clauses..