MySQL 分析

Question

MySQL 分析中可以使用 SET profiling = 1; 设置

查询SHOW PROFILES;显示每个查询所花费的时间。我想知道这个时间是否只包括服务器上的执行时间，还是还包括将结果发送到前端所需的时间。

谢谢

Answer 1

根据manual状态正在发送数据是将结果发送到客户端所需的时间。示例:

mysql> SHOW PROFILE FOR QUERY 1;
+--------------------------------+----------+
| Status                         | Duration |
+--------------------------------+----------+
| starting                       | 0.000024 |
| Waiting for query cache lock   | 0.000005 |
| checking query cache for query | 0.000051 |
| checking permissions           | 0.000010 |
| Opening tables                 | 0.000022 |
| System lock                    | 0.000012 |
| Waiting for query cache lock   | 0.000024 |
| init                           | 0.000043 |
| optimizing                     | 0.000008 |
| statistics                     | 0.000012 |
| preparing                      | 0.000011 |
| executing                      | 0.000004 |
| Sorting result                 | 0.125893 |
| Sending data                   | 0.000076 | -- here
| end                            | 0.000005 |
| query end                      | 0.000002 |
| closing tables                 | 0.000005 |
| freeing items                  | 0.000005 |
| Waiting for query cache lock   | 0.000001 |
| freeing items                  | 0.000012 |
| Waiting for query cache lock   | 0.000001 |
| freeing items                  | 0.000001 |
| storing result in query cache  | 0.000013 |
| logging slow query             | 0.000001 |
| cleaning up                    | 0.000002 |
+--------------------------------+----------+

更新:使用查询缓存时，状态可能是将缓存结果发送到客户端。