If you enable slow queries log of MySQL database server, you will notice that from the slow query log file contains only SQL statements and queries that took more than query_time of 10 seconds to execute or run. This is the default value or query time threshold for log_slow_queries function, which is 10 seconds. 10 seconds is way too long for a SQL query to complete, so the value may be too high to capture any meaningful data. You can alter or change the slow query time to lower value or number of seconds.

You can set a new long_query_time in the MySQL configuration file, namely my.cnf or my.ini, normally located in /etc directory. Simply add the following line to the configuration file:

long_query_time = 5

Above option will set the slow or long query limit as 5 seconds, which means MySQL will capture and log all SQL queries that took longer than 5 seconds to execute and finish running to the log file.