The Slow Query Log. If a query takes longer than the value specified this query will be recorded in the slow query log file. Slow_query_log1 long_query_time1 log_outputFILE slow_query_log_filevarlibmysqlslowlog.
The slow query log consists of SQL statements that took more than long_query_time seconds to execute required at least min_examined_row_limit rows to be examined and fulfilled other criteria specified by the slow query log. Slow query logs are disabled by default and can be enabled to assist with identifying performance bottlenecks during troubleshooting. This greatly simplifies the task of finding inefficient or time-consuming queries.
Configure slow query logging.
This allows you to find inefficient SQL queries that can be optimized to improve database performance. By identifying queries that are particularly slow in their execution you can address them by restructuring the application that triggers your queries. However in order to determine which queries require most urgent attention it is an advantage to summarize the slow query log. Slow_query_log 1 slow_query_log_file slow-querylog long_query_time 2.