- mysql8中测试
- 查看profiling 是否开启
select @@profiling;
show variables like 'profiling';
- profiling=0 代表关闭，我们需要把 profiling 打开，即设置为 1：
set profiling=1;
- 任意执行1条查询语句
MariaDB [jdbc]> select * from t_account;
+----+----------+-------+
| id | username | money |
+----+----------+-------+
| 1 | goudan | 900 |
| 2 | gousheng | 1100 |
+----+----------+-------+
2 rows in set (0.000 sec)
- 查看
MariaDB [jdbc]> show profiles;
+----------+------------+---------------------------------+
| Query_ID | Duration | Query |
+----------+------------+---------------------------------+
| 1 | 0.00133903 | show variables like 'profiling' |
| 2 | 0.00015757 | select @@profiling |
| 3 | 0.00007482 | select * from t_account |
| 4 | 0.00007830 | select * from t_account |
| 5 | 0.00006953 | select * from t_account |
| 6 | 0.00006093 | select * from t_account |
| 7 | 0.00006677 | select * from t_account |
| 8 | 0.00007320 | select * from t_account |
| 9 | 0.00007997 | select * from t_account |
| 10 | 0.00007702 | select * from t_account |
| 11 | 0.00006816 | select * from t_account |
+----------+------------+---------------------------------+
11 rows in set (0.000 sec)
MariaDB [jdbc]> show profile;
+--------------------------------+----------+
| Status | Duration |
+--------------------------------+----------+
| Starting | 0.000025 |
| Waiting for query cache lock | 0.000004 |
| Init | 0.000003 |
| Checking query cache for query | 0.000007 |
| Checking privileges on cached | 0.000004 |
| Checking permissions | 0.000008 |
| Sending cached result to clien | 0.000010 |
| Updating status | 0.000004 |
| Reset for next command | 0.000003 |
+--------------------------------+----------+
9 rows in set (0.002 sec)
- 查询指定的 Query ID
MariaDB [jdbc]> show profile for query 7;
+--------------------------------+----------+
| Status | Duration |
+--------------------------------+----------+
| Starting | 0.000026 |
| Waiting for query cache lock | 0.000004 |
| Init | 0.000003 |
| Checking query cache for query | 0.000006 |
| Checking privileges on cached | 0.000003 |
| Checking permissions | 0.000008 |
| Sending cached result to clien | 0.000010 |
| Updating status | 0.000004 |
| Reset for next command | 0.000003 |
+--------------------------------+----------+
9 rows in set (0.000 sec)
- 查询更多信息
MariaDB [jdbc]> show profile cpu,block io for query 6;
+--------------------------------+----------+----------+------------+--------------+---------------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out |
+--------------------------------+----------+----------+------------+--------------+---------------+
| Starting | 0.000023 | 0.000010 | 0.000012 | 0 | 0 |
| Waiting for query cache lock | 0.000003 | 0.000001 | 0.000002 | 0 | 0 |
| Init | 0.000002 | 0.000001 | 0.000001 | 0 | 0 |
| Checking query cache for query | 0.000005 | 0.000002 | 0.000003 | 0 | 0 |
| Checking privileges on cached | 0.000003 | 0.000001 | 0.000002 | 0 | 0 |
| Checking permissions | 0.000006 | 0.000003 | 0.000003 | 0 | 0 |
| Sending cached result to clien | 0.000012 | 0.000005 | 0.000007 | 0 | 0 |
| Updating status | 0.000004 | 0.000002 | 0.000002 | 0 | 0 |
| Reset for next command | 0.000003 | 0.000001 | 0.000002 | 0 | 0 |
+--------------------------------+----------+----------+------------+--------------+---------------+
9 rows in set (0.000 sec)
- mysql5中测试
# 在 /etc/my.cnf 中新增一行：开启查询缓存
query_cache_type=1
# 重启
systemctl restart mysqld
# 开启profiling
set profiling=1;
# 任意执行1条查询语句
select * from locations;
# 查看
show profile for query 1;
- sql语法顺序
