IT/DBMS (1) 썸네일형 리스트형 mysql query 성능 1. explain extra 컬럼 using filesort ( https://www.percona.com/blog/2009/03/05/what-does-using-filesort-mean-in-mysql/ ) First of all, this is Using temporary econdly, temporary tables may go to disk if they are too big, but EXPLAIN doesn’t show that. using where. 이건 where 를 통해서 갯수가 제한되는 상황이면 보이는 것 같음 2. profiling SET profiling = 1; // 활성화 SET profiling = 0; // 비활성화 SHOW PROFILES; show profile all.. 이전 1 다음