select … into outfile 备份恢复（load data）以及mysqldump时间对比

select … into outfile 'path' 备份

此种方式恢复速度非常快，比insert的插入速度要快的多，他跟有备份功能丰富的mysqldump不同的是，他只能备份表中的数据，并不能包含表的结构。如果备份完成之后，表被drop,是无法实现恢复操作的（除非有表结构）。

mysql> select * from t1 into outfile '/mydata/mysql/mysql3307/data/t1.sql';

ERROR 1290 (HY000): The MySQL server is running with the --secure-file-priv option so it cannot execute this statement

mysql> show variables like '%secure%';

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

| Variable_name | Value |

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

| require_secure_transport | OFF |

| secure_auth | ON |

| secure_file_priv | NULL |

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

3 rows in set (0.00 sec)

mysql> set secure_file_priv='/tmp';

ERROR 1238 (HY000): Variable 'secure_file_priv' is a read only variable

mysql> set session secure_file_priv=='/tmp';

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '=='/tmp'' at line 1

mysql>

关闭MYSQL数据库，设置secure_file_priv 目录。

[root@mysql5 ~]# mysqladmin -S /tmp/mysql3307.sock -uroot -pmysql shutdown

mysqladmin: [Warning] Using a password on the command line interface can be insecure.

[root@mysql5 ~]#

[root@mysql5 ~]# ps -ef |grep mysql

root 3506 2071 0 01:24 pts/1 00:00:00 grep mysql

[root@mysql5 ~]#

vi /etc/my3307.cnf

[mysqld]里面加入

secure_file_priv=/tmp

启动后查看

mysql> show global variables like '%secu%';

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

| Variable_name | Value |

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

| require_secure_transport | OFF |

| secure_auth | ON |

| secure_file_priv | /tmp/ |

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

3 rows in set (0.01 sec)

select * from t1 into outfile '/tmp/t1_onlydata.sql';

mysql> select * from t1 into outfile '/tmp/t1_onlydata.sql';

Query OK, 972864 rows affected (1.12 sec)

mysql> desc t1;

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

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

| id | int(4) | YES | MUL | NULL | |

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

1 row in set (0.00 sec)

全是文本文件数据。

select … into outfile 'path' 恢复

清除t1表数据，并进行恢复

mysql> truncate table t1;

Query OK, 0 rows affected (0.04 sec)

mysql> desc t1;

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

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

| id | int(4) | YES | MUL | NULL | |

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

1 row in set (0.00 sec)

LOAD DATA恢复数据（只能恢复数据）

语法：

LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name'

[REPLACE | IGNORE]

INTO TABLE tbl_name

[PARTITION (partition_name [, partition_name] ...)]

[CHARACTER SET charset_name]

[{FIELDS | COLUMNS}

[TERMINATED BY 'string']

[[OPTIONALLY] ENCLOSED BY 'char']

[ESCAPED BY 'char']

]

[LINES

[STARTING BY 'string']

[TERMINATED BY 'string']

]

[IGNORE number {LINES | ROWS}]

[(col_name_or_user_var

[, col_name_or_user_var] ...)]

[SET col_name={expr | DEFAULT},

[, col_name={expr | DEFAULT}] ...]

load data INFILE '/tmp/t1_onlydata.sql' INTO TABLE test.t1;

查看表数据：

恢复成功。

load data 与insert的插入速度对比

于是，我猜想可以用mysqldump进行表结构的备份，用select …into outfile 备份数据，load data 恢复数据，测试两者速度。

创建一张表。

delimiter //

create procedure per2()

begin

declare i int;

set i=1;

while i <= 1000000 do

insert into test.L values(i,'aaaaa');

set i=i+1;

end while;

end

执行存储过程：

call per2();

查看数据（实际我只插入仅14万行数据）

mysqldump备份元数据文件

mysqldump -S /tmp/mysql3307.sock -uroot -pmysql --single-transaction --set-gtid-purged=OFF test L -d > /tmp/L_meta.sql

select … into outfile 'path' 备份

select * from test.L into outfile '/tmp/20180525test_Ldata.sql'

mysqldump备份整个表

mysqldump -S /tmp/mysql3307.sock -uroot -pmysql --single-transaction --set-gtid-purged=OFF test L > /tmp/L_table.sql

恢复时间对比

1、MYSQLdump先恢复表结构（或者直接建表）

先删除，恢复表结构。

恢复表结构：

这核时间很快，就是建一张表的时间，不计算进去对整体时间没有影响。

例如我建表：

建表时间0.03s。

2、load data恢复时间

load data INFILE '/tmp/20180525test_Ldata.sql' INTO TABLE test.L;

时间是1.59s。

3、MYSQLDUMP这种插入方式恢复

time mysql -S /tmp/mysql3307.sock -uroot -pmysql test < /tmp/L_table.sql

将近2s MYSQLDUMP恢复时间。

总结

元数据恢复+LOAD DATA时间一共

T1=0.03+1.59=1.62s

MYSQLDUMP恢复一共花了

T2=1.99s

对于14万数据，load data比mysqldump快了近1/4，对于大数据量，应该快更多，在允许的情况下，可以利用元数据（或者表结构），配合LOAD DATA恢复单表。