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标题:
MySQL 性能跟踪语句
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作者:
itlinux
时间:
2008-02-28 14:54
标题:
MySQL 性能跟踪语句
MYSQL5.0家族提供的性能跟踪器确实很爽。
要注意两点。
1、不过版本要在5.0.37之后
手册上介绍：(SHOW PROFILES and SHOW PROFILE were added in MySQL 5.0.37. )ImportantPlease note that the SHOW PROFILE and SHOW PROFILES functionality is part of the MySQL 5.0 Community Server only.
2、变量profiling是用户变量，每次都得重新启用。
以下是我做的一些实验。数据很明显，就不多解释了。
mysql> use test
Database changed
mysql> set profiling=1;
Query OK, 0 rows affected (0.00 sec)
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| bag_item |
| bag_user |
| score |
| t |
+----------------+
4 rows in set (0.03 sec)
mysql> select count(*) from t;
+----------+
| count(*) |
+----------+
| 2097152 |
+----------+
1 row in set (0.74 sec)
mysql> show profiles;
+----------+------------+------------------------+
| Query_ID | Duration | Query |
+----------+------------+------------------------+
| 1 | 0.02717000 | show tables |
| 2 | 0.74770100 | select count(*) from t |
+----------+------------+------------------------+
2 rows in set (0.00 sec)
mysql> show profile for query 2;
+--------------------------------+----------+
| Status | Duration |
+--------------------------------+----------+
| (initialization) | 0.000004 |
| checking query cache for query | 0.000044 |
| Opening tables | 0.000012 |
| System lock | 0.000017 |
| Table lock | 0.00003 |
| init | 0.000013 |
| optimizing | 0.000008 |
| statistics | 0.000013 |
| preparing | 0.000011 |
| executing | 0.000006 |
| Sending data | 0.747313 |
| end | 0.000014 |
| query end | 0.000006 |
| storing result in query cache | 0.000006 |
| freeing items | 0.000012 |
| closing tables | 0.000009 |
| logging slow query | 0.000183 |
+--------------------------------+----------+
17 rows in set (0.00 sec)
mysql> show profile block io,cpu for query 2;
+--------------------------------+----------+----------+------------+--------------+---------------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out |
+--------------------------------+----------+----------+------------+--------------+---------------+
| (initialization) | 0.000004 | 0 | 0 | 0 | 0 |
| checking query cache for query | 0.000044 | 0 | 0 | 0 | 0 |
| Opening tables | 0.000012 | 0 | 0 | 0 | 0 |
| System lock | 0.000017 | 0 | 0 | 0 | 0 |
| Table lock | 0.00003 | 0 | 0 | 0 | 0 |
| init | 0.000013 | 0 | 0 | 0 | 0 |
| optimizing | 0.000008 | 0 | 0 | 0 | 0 |
| statistics | 0.000013 | 0 | 0 | 0 | 0 |
| preparing | 0.000011 | 0 | 0 | 0 | 0 |
| executing | 0.000006 | 0 | 0 | 0 | 0 |
| Sending data | 0.747313 | 0.746887 | 0 | 0 | 0 |
| end | 0.000014 | 0 | 0 | 0 | 0 |
| query end | 0.000006 | 0 | 0 | 0 | 0 |
| storing result in query cache | 0.000006 | 0 | 0 | 0 | 0 |
| freeing items | 0.000012 | 0 | 0 | 0 | 0 |
| closing tables | 0.000009 | 0 | 0 | 0 | 0 |
| logging slow query | 0.000183 | 0 | 0 | 0 | 0 |
+--------------------------------+----------+----------+------------+--------------+---------------+
17 rows in set (0.00 sec)
mysql> insert into t(username) select username from t;
Query OK, 2097152 rows affected (34.17 sec)
Records: 2097152 Duplicates: 0 Warnings: 0
mysql> show profiles;
+----------+-------------+------------------------------------------------+
| Query_ID | Duration | Query |
+----------+-------------+------------------------------------------------+
| 1 | 0.02717000 | show tables |
| 2 | 0.74770100 | select count(*) from t |
| 3 | 0.00004200 | show prifile for query 2 |
| 4 | 34.30410100 | insert into t(username) select username from t |
+----------+-------------+------------------------------------------------+
4 rows in set (0.00 sec)
mysql> show profile cpu,block io,memory,swaps for query 4;
+------------------------------+-----------+-----------+------------+--------------+---------------+-------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out | Swaps |
+------------------------------+-----------+-----------+------------+--------------+---------------+-------+
| (initialization) | 0.000038 | 0 | 0 | 0 | 0 | 0 |
| checking permissions | 0.000016 | 0 | 0 | 0 | 0 | 0 |
| Opening tables | 0.000014 | 0 | 0 | 0 | 0 | 0 |
| System lock | 0.000007 | 0 | 0 | 0 | 0 | 0 |
| Table lock | 0.000013 | 0 | 0 | 0 | 0 | 0 |
| init | 0.000015 | 0 | 0 | 0 | 0 | 0 |
| optimizing | 0.000006 | 0 | 0 | 0 | 0 | 0 |
| statistics | 0.000012 | 0 | 0 | 0 | 0 | 0 |
| preparing | 0.000011 | 0 | 0 | 0 | 0 | 0 |
| Creating tmp table | 0.000029 | 0 | 0 | 0 | 0 | 0 |
| executing | 0.000005 | 0 | 0 | 0 | 0 | 0 |
| Copying to tmp table | 1.262877 | 1.24981 | 0.012998 | 0 | 0 | 0 |
| converting HEAP to MyISAM | 0.384814 | 0.187971 | 0.19797 | 0 | 0 | 0 |
| Copying to tmp table on disk | 1.417069 | 1.203817 | 0.191971 | 0 | 0 | 0 |
| Sending data | 31.104185 | 13.965877 | 0.843872 | 0 | 0 | 0 |
| end | 0.000017 | 0 | 0 | 0 | 0 | 0 |
| removing tmp table | 0.134872 | 0 | 0.029995 | 0 | 0 | 0 |
| end | 0.000026 | 0 | 0 | 0 | 0 | 0 |
| query end | 0.000006 | 0 | 0 | 0 | 0 | 0 |
| freeing items | 0.000011 | 0 | 0 | 0 | 0 | 0 |
| closing tables | 0.000009 | 0 | 0 | 0 | 0 | 0 |
| logging slow query | 0.000049 | 0 | 0 | 0 | 0 | 0 |
+------------------------------+-----------+-----------+------------+--------------+---------------+-------+
22 rows in set (0.00 sec)
mysql> select count(*) from t;
+----------+
| count(*) |
+----------+
| 4194304 |
+----------+
1 row in set (1.51 sec)
mysql> show profiles;
+----------+-------------+------------------------------------------------+
| Query_ID | Duration | Query |
+----------+-------------+------------------------------------------------+
| 1 | 0.02717000 | show tables |
| 2 | 0.74770100 | select count(*) from t |
| 3 | 0.00004200 | show prifile for query 2 |
| 4 | 34.30410100 | insert into t(username) select username from t |
| 5 | 1.50563800 | select count(*) from t |
+----------+-------------+------------------------------------------------+
5 rows in set (0.00 sec)
mysql> show profile cpu,block io,memory,swaps,context switches,source for query 5;
+--------------------------------+----------+----------+------------+-------------------+---------------------+--------------+---------------+-------+---------------------------+---------------+-------------+
| Status | Duration | CPU_user | CPU_system | Context_voluntary | Context_involuntary | Block_ops_in | Block_ops_out | Swaps | Source_function | Source_file | Source_line |
+--------------------------------+----------+----------+------------+-------------------+---------------------+--------------+---------------+-------+---------------------------+---------------+-------------+
| (initialization) | 0.000004 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | send_result_to_client | sql_cache.cc | 1099 |
| checking query cache for query | 0.000048 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | open_tables | sql_base.cc | 2629 |
| Opening tables | 0.000011 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_lock_tables | lock.cc | 153 |
| System lock | 0.000007 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_lock_tables | lock.cc | 162 |
| Table lock | 0.000032 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_select | sql_select.cc | 2242 |
| init | 0.000013 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | optimize | sql_select.cc | 745 |
| optimizing | 0.000008 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | optimize | sql_select.cc | 904 |
| statistics | 0.000013 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | optimize | sql_select.cc | 914 |
| preparing | 0.000011 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | exec | sql_select.cc | 1565 |
| executing | 0.000006 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | exec | sql_select.cc | 2083 |
| Sending data | 1.505401 | 1.504771 | 0 | 3 | 5 | 0 | 0 | 0 | mysql_select | sql_select.cc | 2287 |
| end | 0.000015 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_execute_command | sql_parse.cc | 5122 |
| query end | 0.000005 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | query_cache_end_of_result | sql_cache.cc | 729 |
| storing result in query cache | 0.000007 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_parse | sql_parse.cc | 6116 |
| freeing items | 0.00001 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | dispatch_command | sql_parse.cc | 2146 |
| closing tables | 0.000009 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | log_slow_statement | sql_parse.cc | 2204 |
| logging slow query | 0.000038 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | dispatch_command | sql_parse.cc | 2169 |
+--------------------------------+----------+----------+------------+-------------------+---------------------+--------------+---------------+-------+---------------------------+---------------+-------------+
17 rows in set (0.00 sec)
mysql> update t set username = 'waill';
Query OK, 4194304 rows affected (44.82 sec)
Rows matched: 4194304 Changed: 4194304 Warnings: 0
mysql> show profiles;
+----------+-------------+------------------------------------------------+
| Query_ID | Duration | Query |
+----------+-------------+------------------------------------------------+
| 1 | 0.02717000 | show tables |
| 2 | 0.74770100 | select count(*) from t |
| 3 | 0.00004200 | show prifile for query 2 |
| 4 | 34.30410100 | insert into t(username) select username from t |
| 5 | 1.50563800 | select count(*) from t |
| 6 | 44.82054700 | update t set username = 'waill' |
+----------+-------------+------------------------------------------------+
6 rows in set (0.00 sec)
mysql> show profile cpu,block io,memory,swaps,context switches,source for query 6;
+----------------------+-----------+-----------+------------+-------------------+---------------------+--------------+---------------+-------+-----------------------+---------------+-------------+
| Status | Duration | CPU_user | CPU_system | Context_voluntary | Context_involuntary | Block_ops_in | Block_ops_out | Swaps | Source_function | Source_file | Source_line |
+----------------------+-----------+-----------+------------+-------------------+---------------------+--------------+---------------+-------+-----------------------+---------------+-------------+
| (initialization) | 0.000035 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | check_access | sql_parse.cc | 5306 |
| checking permissions | 0.000011 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | open_tables | sql_base.cc | 2629 |
| Opening tables | 0.000011 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_lock_tables | lock.cc | 153 |
| System lock | 0.000007 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_lock_tables | lock.cc | 162 |
| Table lock | 0.000008 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_update | sql_update.cc | 167 |
| init | 0.000021 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_update | sql_update.cc | 429 |
| Updating | 44.514679 | 27.976747 | 2.818571 | 9949 | 1584 | 0 | 0 | 0 | mysql_update | sql_update.cc | 560 |
| end | 0.305671 | 0.028996 | 0.023997 | 43 | 18 | 0 | 0 | 0 | mysql_execute_command | sql_parse.cc | 5122 |
| query end | 0.000026 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | mysql_parse | sql_parse.cc | 6116 |
| freeing items | 0.000016 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | dispatch_command | sql_parse.cc | 2146 |
| closing tables | 0.000012 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | log_slow_statement | sql_parse.cc | 2204 |
| logging slow query | 0.00005 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | dispatch_command | sql_parse.cc | 2169 |
+----------------------+-----------+-----------+------------+-------------------+---------------------+--------------+---------------+-------+-----------------------+---------------+-------------+
12 rows in set (0.00 sec)
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