mysql慢查詢的奇異事件

zlingyi發表於2017-12-11
MySql事件

開啟mysql慢查詢日誌，發現有很多sql查詢時間很短，明顯不到0.01s的sql竟然也在慢日誌查詢裡面，日誌詳細情況如下：
# User@Host: otterpro[otterpro] @  [172.22.53.122]  Id:  2061
# Schema: otter  Last_errno: 0  Killed: 0
# Query_time: 0.000559  Lock_time: 0.000080  Rows_sent: 3  Rows_examined: 327  Rows_affected: 0
# Bytes_sent: 755
SET timestamp=1512715920;
select   ID,NODE_ID,PIPELINE_ID,LOCATION,GMT_CREATE,GMT_MODIFIED     from PIPELINE_NODE_RELATION where NODE_ID = 74 ORDER BY ID DESC;
# Time: 171208 14:52:08
# User@Host: otterpro[otterpro] @  [172.22.53.122]  Id:  2061
# Schema: otter  Last_errno: 0  Killed: 0
# Query_time: 0.000214  Lock_time: 0.000110  Rows_sent: 2  Rows_examined: 2  Rows_affected: 0
# Bytes_sent: 821
SET timestamp=1512715928;
select   ID,CLUSTER_NAME,SERVER_LIST,DESCRIPTION,GMT_CREATE,GMT_MODIFIED   from AUTOKEEPER_CLUSTER    ORDER BY ID ASC;

有點懷疑再次檢視了引數：

mysql>  show global status like '%slow_queries%';
+---------------+---------+
| Variable_name | Value   |
+---------------+---------+
| Slow_queries  | 6055683 |
+---------------+---------+

mysql> show variables like '%slow_query_log%';
+------------------------------------+--------------------------------+
| Variable_name                      | Value                          |
+------------------------------------+--------------------------------+
| slow_query_log                     | ON                             |
| slow_query_log_always_write_time   | 10.000000                      |
| slow_query_log_file                | /data/mysql/13306/tmp/slow.log |
| slow_query_log_timestamp_always    | OFF                            |
| slow_query_log_timestamp_precision | second                         |
| slow_query_log_use_global_control  |                                |
+------------------------------------+--------------------------------+
6 rows in set (0.01 sec)
mysql> show variables like 'long_query_time';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 0.100000 |
+-----------------+----------+
1 row in set (0.00 sec)

mysql> show global variables like '%general%'; 
+------------------+--------------------------------+
| Variable_name    | Value                          |
+------------------+--------------------------------+
| general_log      | OFF                            |
| general_log_file | /data/mysql/13306/tmp/file.sql |
+------------------+--------------------------------+
2 rows in set (0.00 sec)



log-queries-not-using-indexes


如果執行的SQL語句沒有使用索引，則mysql資料庫同樣會將這條SQL語句記錄到慢查詢日誌檔案中。

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/28686045/viewspace-2148532/，如需轉載，請註明出處，否則將追究法律責任。

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