MySQL中的存储引擎及InnoDB简单介绍

+-------------------------+
|    连接/会话层          |
+-------------------------+
|    SQL解析/优化层       |
+-------------------------+
|    存储引擎接口层       |
+-------------------------+
| InnoDB | MyISAM | Memory | ... |
+-------------------------+

mysql> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| FEDERATED          | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
| MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
| MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
9 rows in set (0.00 sec)

mysql> select @@default_storage_engine;
+--------------------------+
| @@default_storage_engine |
+--------------------------+
| InnoDB                   |
+--------------------------+
1 row in set (0.00 sec)

show create table 表名;

# 修改配置文件，然后重启mysql即可
vim /etc/my.cnf
# 修改下面的配置 
[mysqld]
default_storage_engine=InnoDB

#创建表时设置
create table xxx (id int) engine=innodb charset=utf8mb4;
#创建表之后设置
alter table xxx engine=myisam;
alter table world.xxx engine=innodb;

#查看共享表空间
mysql> select @@innodb_data_file_path;
+-------------------------+
| @@innodb_data_file_path |
+-------------------------+
| ibdata1:12M:autoextend  |
+-------------------------+
1 row in set (0.00 sec)

#查看共享表空间默认扩展大小，默认每次扩展64M
mysql> select @@innodb_autoextend_increment;
+-------------------------------+
| @@innodb_autoextend_increment |
+-------------------------------+
|                            64 |
+-------------------------------+
1 row in set (0.00 sec)

# 编写数据库配置文件信息
vim /etc/my.cnf
[mysqld]
innodb_data_file_path=ibdata1:12M;ibdata2:100M;ibdata3:100M:autoextend
-- 需要注意的是ibdata1文件大小必须和实际数据库要存储的数据相匹配，否则会出现如下报错信息
 [ERROR] [MY-012264] [InnoDB] The innodb_system data file './ibdata1' is of a different size 768 pages (rounded down to MB) than the 4864 pages specified in the .cnf file!
-- 表示ibdate1指定大小超过了原有ibdata1实际的大小尺寸

# 初始化配置文件
root@master:~# vim /etc/my.cnf
[mysqld]
innodb_data_file_path=ibdata1:100M;ibdata2:100M;ibdata3:100M:autoextend
# 模拟初始化操作命令
root@master:~# mysqld --initialize-insecure --user=mysql --basedir=/usr/local/mysql --datadir=/data/3306/data
# 模拟初始化重启服务
root@master:~# /etc/init.d/mysqld start

#表示每个表就是一个独立文件，进行数据信息的独立存储，不建议进行修改，如果改为0就是所有数据统一存储在共享表空间
select @@innodb_file_per_table;
+---------------------------------+
| @@innodb_file_per_table |
+---------------------------------+
|                                 1 |
+---------------------------------+
#设置为0表示利用共享表空间存储用户数据 1表示利用独立表空间存储用户数据
set global innodb_file_per_table=0

# 步骤一：锁定源端t100w表
# 给t100w表加写数据锁
mysql > lock tables test.t100w write;
# 获取创建表结构数据信息
mysql > show create table test.t100w;
CREATE TABLE `t100w` (
  `id` int DEFAULT NULL,
  `num` int DEFAULT NULL,
  `k1` char(2) DEFAULT NULL,
  `k2` char(4) DEFAULT NULL,
  `dt` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  KEY `idx` (`k1`,`k2`,`num`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci |
#步骤二：目标端创建oldboy库和t100w空表
# 创建新的数据库
mysql> create database test;
# 创建新的数据表
mysql > CREATE TABLE `t100w` (
  `id` int DEFAULT NULL,
  `num` int DEFAULT NULL,
  `k1` char(2) DEFAULT NULL,
  `k2` char(4) DEFAULT NULL,
  `dt` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  KEY `idx` (`k1`,`k2`,`num`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
#步骤三：删除目标端空的表空间文件
# 删除t100w表的ibd数据文件信息，但是保留t100w的frm，ibdata1中关于t100w的系统数据
mysql> alter table test.t100w discard tablespace;
#操作步骤四：拷贝源端ibd文件到目标端目录，并设置权限
root@master: ~# cp /data/3306/data/test/t100w.ibd /data/3307/data/test/
root@master: ~# chown -R mysql.mysql /data/*
#操作步骤五：导入表空间
# 在目标端加载识别迁移过来的数据文件信息
mysql> alter table test.t100w import tablespace;
# 查看数据表中是否有迁移过来的数据信息
mysql> select count(*) from t100w;
+----------+
| count(*) |
+----------+
|  1000000 |
+----------+
1 row in set (0.04 sec)
#步骤六：解锁源端数据库
mysql> unlock tables;

# 设置undo表空间文件数量（默认2个文件）
mysql> select @@innodb_undo_tablespaces;
+---------------------------+
| @@innodb_undo_tablespaces |
+---------------------------+
|                         2 |
+---------------------------+
1 row in set (0.00 sec)
# 设置undo表空间文件大小（字节）
mysql> select @@innodb_max_undo_log_size;
+----------------------------+
| @@innodb_max_undo_log_size |
+----------------------------+
|                 1073741824 |
+----------------------------+
1 row in set (0.00 sec)
# 设置undo表空间回收机制（默认开启）
mysql> select @@innodb_undo_log_truncate;
+----------------------------+
| @@innodb_undo_log_truncate |
+----------------------------+
|                          1 |
+----------------------------+
1 row in set (0.00 sec)
# 设置undo表空间信息检测次数 （128次）
mysql> select @@innodb_purge_rseg_truncate_frequency; 
+----------------------------------------+
| @@innodb_purge_rseg_truncate_frequency |
+----------------------------------------+
|                                    128 |
+----------------------------------------+
1 row in set (0.00 sec)

# 关闭数据库服务程序，清理数据库服务数据目录
root@master:~# vim /etc/my.cnf
[mysqld]
innodb_undo_tablespaces=3
innodb_max_undo_log_size=128M
innodb_undo_log_truncate=ON
innodb_purge_rseg_truncate_frequency=32

mysql> select @@innodb_temp_data_file_path;
+------------------------------+
| @@innodb_temp_data_file_path |
+------------------------------+
| ibtmp1:12M:autoextend        |
+------------------------------+
1 row in set (0.00 sec)
mysql> select @@innodb_autoextend_increment;
+-------------------------------+
| @@innodb_autoextend_increment |
+-------------------------------+
|                            64 |
+-------------------------------+
1 row in set (0.00 sec)

vim /etc/my.cnf
[mysqld]
innodb_temp_data_file_path=ibtmp1:12M;ibtmp2:120M:autoextend:max:500M

mysql> show variables like '%innodb_log_file%';
+---------------------------+----------+
| Variable_name             | Value    |
+---------------------------+----------+
| innodb_log_file_size      | 50331648 |
| innodb_log_files_in_group | 2        |
+---------------------------+----------+
2 rows in set (0.01 sec)

# 编写数据库配置文件信息
vim /etc/my.cnf
[mysqld]
innodb_log_file_size=100M
innodb_log_files_in_group=3

+-------------------------+
| Buffer Pool（缓冲池）   |
|  - 数据页缓存           |
|  - 索引页缓存           |
|  - 自适应哈希索引       |
|  - 插入缓冲             |
|  - 锁信息、数据字典等   |
+-------------------------+
| Log Buffer（日志缓冲）  |
+-------------------------+

mysql> select @@innodb_buffer_pool_size;
+---------------------------+
| @@innodb_buffer_pool_size |
+---------------------------+
|                1073741824 |
+---------------------------+
1 row in set (0.00 sec)

# buffer pool默认内存空间大小为128M，生产建议大小可以设置为物理内存总量的50%~80%
方式一：
set global innodb_buffer_pool_size=268435456;
方式二：
vim /etc/my.cnf
[mysqld]
innodb_buffer_pool_size=256M

mysql> select @@innodb_log_buffer_size;
+--------------------------+
| @@innodb_log_buffer_size |
+--------------------------+
|                 16777216 |
+--------------------------+
1 row in set (0.00 sec)

方式一：
set global innodb_log_buffer_size=33554432;
方式二：
vim /etc/my.cnf
[mysqld]
innodb_log_buffer_size=32M