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profiling mysql_MySQL如何利用profiling分析SQL查询语句

时间:2022-12-01 09:54:36

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profiling mysql_MySQL如何利用profiling分析SQL查询语句

查看profiling是否开启:

mysql> select @@profiling;

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

| @@profiling |

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

|0 |

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

1 row in set (0.00 sec)

开启profiling:

mysql> set profiling=1;

Query OK, 0 rows affected (0.00 sec)

mysql> select @@profiling;

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

| @@profiling |

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

|1 |

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

1 row in set (0.00 sec)

执行若干条SQL查询:

mysql> use mysql

Database changed

mysql> select database();

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

| database() |

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

| mysql |

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

1 row in set (0.00 sec)

mysql> select host,user,Password from user limit 10;

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

| host | user| Password |

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

| localhost | root| *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| %| chenfeng | *716E7D76E850A91A8311F35B6BFB1213B751F230 |

| %| test@localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| %| sa@localhost | *4D0DD2673C1DE57138354E81A957460B774C4BC2 |

| %| admin@localhost | *4ACFE3202A5FF5CF467898FC58AAB1D615029441 |

| localhost | dsf | *AFED783E50FCEF7B1C89AC89C6E1A0405BD7F313 |

| localhost | dsf1| *98D1D8D997EA32BABDFEEC2EBB62BB6D010036C6 |

| %| dsf2| *0007B182797FAD2A8A37C3F73A011BBD36C49857 |

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

8 rows in set (0.00 sec)

查询上述语句的Profiling情况:

mysql> show profiles;

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

| Query_ID | Duration | Query|

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

| 1 | 0.00012600 | select @@profiling |

| 2 | 0.00018450 | SELECT DATABASE() |

| 3 | 0.00011950 | select database() |

| 4 | 0.11296025 | show columns from user |

| 5 | 0.00038725 | select host,user,Password from user limit 10 |

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

14 rows in set (0.00 sec)

查看Query_ID=5语句的I/O消耗情况:

mysql> show profile block io for query 5;

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

| Status | Duration | Block_ops_in | Block_ops_out |

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

| starting | 0.000018 |NULL |NULL |

| Waiting for query cache lock | 0.000003 |NULL |NULL |

| checking query cache for query | 0.000077 |NULL |NULL |

| checking permissions| 0.000009 |NULL |NULL |

| Opening tables | 0.000020 |NULL |NULL |

| System lock| 0.000014 |NULL |NULL |

| init | 0.000020 |NULL |NULL |

| optimizing | 0.000005 |NULL |NULL |

| statistics | 0.000011 |NULL |NULL |

| preparing | 0.000009 |NULL |NULL |

| executing | 0.000003 |NULL |NULL |

| Sending data| 0.000071 |NULL |NULL |

| end | 0.000004 |NULL |NULL |

| query end | 0.000002 |NULL |NULL |

| closing tables | 0.000011 |NULL |NULL |

| freeing items | 0.000101 |NULL |NULL |

| logging slow query | 0.000006 |NULL |NULL |

| cleaning up| 0.000004 |NULL |NULL |

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

18 rows in set (0.00 sec)

查看Query_ID=5语句的CPU消耗情况:

mysql> show profile cpu for query 5;

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

| Status | Duration | CPU_user | CPU_system |

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

| starting | 0.000018 | 0.000000 | 0.000000 |

| Waiting for query cache lock | 0.000003 | 0.000000 | 0.000000 |

| checking query cache for query | 0.000077 | 0.000000 | 0.000000 |

| checking permissions| 0.000009 | 0.000000 | 0.000000 |

| Opening tables | 0.000020 | 0.000000 | 0.000000 |

| System lock| 0.000014 | 0.000000 | 0.000000 |

| init | 0.000020 | 0.000000 | 0.000000 |

| optimizing | 0.000005 | 0.000000 | 0.000000 |

| statistics | 0.000011 | 0.000000 | 0.000000 |

| preparing | 0.000009 | 0.000000 | 0.000000 |

| executing | 0.000003 | 0.000000 | 0.000000 |

| Sending data| 0.000071 | 0.000000 | 0.000000 |

| end | 0.000004 | 0.000000 | 0.000000 |

| query end | 0.000002 | 0.000000 | 0.000000 |

| closing tables | 0.000011 | 0.000000 | 0.000000 |

| freeing items | 0.000101 | 0.000000 | 0.000000 |

| logging slow query | 0.000006 | 0.000000 | 0.000000 |

| cleaning up| 0.000004 | 0.000000 | 0.000000 |

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

18 rows in set (0.00 sec)

mysql>

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