的autocommit（自动提交）默认是开启，其对mysql的性能有一定影响，举个例子来说，如果你插入了1000条数据，mysql会commit1000次的，如果我们把autocommit关闭掉，通过程序来控制，只要一次commit就可以了。
1,我们可以通过set来设置autocommit
- mysql> set global init_connect="set autocommit=0";
- ERROR 1227 (42000): Access denied; you need (at least one of) the SUPER privilege(s) for this operation
- mysql> set autocommit=0;
- Query OK, 0 rows affected (0.00 sec)
-
- mysql> select @@autocommit;
- +--------------+
- | @@autocommit |
- +--------------+
- | 0 |
- +--------------+
- 1 row in set (0.00 sec)
2,我们可以修改mysql的配置文件my.cnf来关闭autocommit
- [mysqld]
- init_connect='SET autocommit=0'
用第二种方法关，有一点要注意，连接mysql用户的权限不能大于启动mysql的用户的权限，不然init_connect='SET autocommit=0'根本不会启作用，也不会报任何错误，汗一个先。看以下实例
- zhangy@ubuntu:~$ mysql -umysql
- Welcome to the MySQL monitor. Commands end with ; or \g.
- Your MySQL connection id is 1
- Server version: 5.5.2-m2-log Source distribution
-
- Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
-
- mysql> select @@autocommit;
- +--------------+
- | @@autocommit |
- +--------------+
- | 0 |
- +--------------+
- 1 row in set (0.00 sec)
-
- mysql> Ctrl-C -- exit!
- Aborted
- zhangy@ubuntu:~$ mysql -uroot
- Welcome to the MySQL monitor. Commands end with ; or \g.
- Your MySQL connection id is 2
- Server version: 5.5.2-m2-log Source distribution
-
- Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
-
- mysql> select @@autocommit;
- +--------------+
- | @@autocommit |
- +--------------+
- | 1 |
- +--------------+
- 1 row in set (0.00 sec)
这个会不会是mysql的bug呢？我在网上找了找这方面的问题，还真有。部分内容如下：
If a user has SUPER privilege, init_connect will not execute
(otherwise if init_connect will a wrong query no one can connect to server).
Note, if init_connect is a wrong query, the connection is closing without any errors
and next command will clause 'lost connection' error.
里面有一点说的很清楚If a user has SUPER privilege, init_connect will not execute，如果用户有更高级的权限，init_connect根本不会执行。
http://blog.csdn.net/ying_593254979/article/details/12095169