mysql 慢查询调试
调试过程
- 开启慢查询配置
- 找到慢查询日志文件
- 测试
- 等抓到日志分析
-- /*查看慢查询时间 */
-- set global slow_query_log=ON;
show variables like "long_query_time";
-- show variables like 'slow%';
-- 测试慢查询
-- SELECT SLEEP(10);
-- 查看慢查询数量
-- show global status like '%slow%';
查看慢查询日志:
➜ ~ tail -f /usr/local/var/mysql/huoyinghuideMacBook-Pro-slow.log
/usr/local/Cellar/mysql/8.0.18_1/bin/mysqld, Version: 8.0.18 (Homebrew). started with:
Tcp port: 3306 Unix socket: /tmp/mysql.sock
Time Id Command Argument
# Time: 2020-07-23T10:07:06.562524Z
# User@Host: root[root] @ localhost [127.0.0.1] Id: 8
# Query_time: 10.000471 Lock_time: 0.000000 Rows_sent: 1 Rows_examined: 1
use db_sanqing;
SET timestamp=1595498816;
-- /*查看慢查询时间 */
-- set global slow_query_log=ON;
-- show variables like "long_query_time";
-- show variables like 'slow%';
SELECT SLEEP(10);
sql优化
- 加索引
- 优化sql