所以，我试图找到不正确使用索引的联接，但是日志中充满了似乎有索引的查询。
我打开slow_query_log并打开log_queries_not_using_indexes并将long_query_time设置为10秒。
日志开始充斥着像这样的行......
Query_time: 0.320889 Lock_time: 0.000030 Rows_sent: 0 Rows_examined: 338336
SET timestamp=1422564398;
select * from fversions where author=155669 order by entryID desc limit 40;
查询时间低于10秒，根据此解释，它似乎使用主键作为索引。
为什么要记录此查询？我无法查看问题查询以向其添加索引。太吵了。
提前致谢！
PS。对此的答案似乎并不适用，因为我有一个＆＃39; where＆＃39;。 MySQL why logged as slow query/log-queries-not-using-indexes when have indexes?
mysql> explain select * from fversions where author=155669 order by entryID desc limit 40;
+----+-------------+-----------+-------+---------------+---------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-----------+-------+---------------+---------+---------+------+------
| 1 | SIMPLE | fversions | index | NULL | PRIMARY | 8 | NULL | 40 | Using where |
+----+-------------+-----------+-------+---------------+---------+---------+----
块引用
- + ------ 1行（0.00秒）
mysql> show variables like 'slow_query_log';
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| slow_query_log | ON |
mysql> show variables like 'long_query_time';
+-----------------+-----------+
| Variable_name | Value |
+-----------------+-----------+
| long_query_time | 10.000000 |
mysql> show variables like 'log_queries_not_using_indexes';
+-------------------------------+-------+
| Variable_name | Value |
+-------------------------------+-------+
| log_queries_not_using_indexes | ON |