分析语句执行步骤并对排出耗时比较多的语句-白红宇

分析语句执行步骤并对排出耗时比较多的语句

阅读量：5338 次

发布时间：2019-06-15

本文共 1501 字，大约阅读时间需要 5 分钟。

mysql>set profiling=1;

mysql>show profiles;

mysql> set @query_id=6;

Query OK, 0 rows affected (0.00 sec)

mysql> select state,sum(duration) as total_R,round(100*sum(duration)/(select sum(duration) from information_schema.profiling where query_id=@query_id),2) as Pct_R,count(*) as Calls,sum(DURATION)/count(*) as "R/Call" from information_schema.profiling where query_id=@query_id group by state order by Total_R DESC;

+----------------------+----------+-------+-------+--------------+

+----------------------+----------+-------+-------+--------------+

| Sending data | 0.026548 | 44.76 | 1 | 0.0265480000 |

| init | 0.025457 | 42.92 | 1 | 0.0254570000 |

| System lock | 0.005633 | 9.50 | 1 | 0.0056330000 |

| query end | 0.001312 | 2.21 | 1 | 0.0013120000 |

| freeing items | 0.000155 | 0.26 | 1 | 0.0001550000 |

| starting | 0.000076 | 0.13 | 1 | 0.0000760000 |

| Opening tables | 0.000029 | 0.05 | 1 | 0.0000290000 |

| statistics | 0.000019 | 0.03 | 1 | 0.0000190000 |

| cleaning up | 0.000019 | 0.03 | 1 | 0.0000190000 |

| closing tables | 0.000017 | 0.03 | 1 | 0.0000170000 |

| end | 0.000015 | 0.03 | 1 | 0.0000150000 |

| preparing | 0.000012 | 0.02 | 1 | 0.0000120000 |

| optimizing | 0.000011 | 0.02 | 1 | 0.0000110000 |

| checking permissions | 0.000011 | 0.02 | 1 | 0.0000110000 |

| executing | 0.000002 | 0.00 | 1 | 0.0000020000 |

+----------------------+----------+-------+-------+--------------+

转载于:https://www.cnblogs.com/lehao/p/3928832.html

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