1. Home
  2. How To
  3. How to enable MySQL slow query log

How to enable MySQL slow query log

The slow query log consists of SQL statements that take more than long_query_time seconds to execute and require at least min_examined_row_limit rows to be examined.

The slow query log can be used to find queries that take a long time to execute and are therefore candidates for optimization.

Here are the steps to enable MySQL slow query log permanently:

Login to server and edit MySQL configuration file 

vi  /etc/my.cnf

Add the following:

#Slow Query Log
#Log file
log-slow-queries = /var/log/slow-queries-log
#Logs queries longer than 2 sec
long_query_time = 2
#Logs queries not using indexes
log-queries-not-using-indexes TRUE

Change ownership of the log file /var/log/slow-queries-log to mysql for user and group.

chown mysql.mysql /var/log/slow-queries-log

Restart mysql

/etc/init.d/mysql restart
Updated on May 31, 2019

Was this article helpful?

Related Articles