问题
I'm having an issue where MySQL seems to be logging queries in the slow query log that are faster than the time specified. I've configured MySQL to log the following:
Server version: 5.1.54-1ubuntu4-log
+---------------------+-------------------------------+
| Variable_name | Value |
+---------------------+-------------------------------+
| log_slow_queries | ON |
| long_query_time | 2.000000 |
| slow_query_log | ON |
| slow_query_log_file | /var/log/mysql/mysql-slow.log |
+---------------------+-------------------------------+
4 rows in set (0.00 sec)
However, in my slow query log I can see that it's logging sub-second queries:
# Time: 121116 17:09:00
# User@Host: user[user] @ ip-10-x-x-x.ec2.internal [x.x.x.x]
# Query_time: 0.007098 Lock_time: 0.000075 Rows_sent: 50 Rows_examined: 2693
I've set the above variable dynamically using 'SET GLOBAL ...', but even before that the long_query_time was set to 1.000000 seconds.
Any idea why MySQL could be logging queries that are faster then what is specified?
回答1:
According to the documentation, there's another option that could cause queries to get logged in the slow query log:
log_queries_not_using_indexes
来源：https://stackoverflow.com/questions/13421266/mysql-slow-query-log-logging-fast-queries