参考文档：
https://www.163.com/dy/article/GI4CH5N305319P76.html
https://learn.lianglianglee.com/专栏/MySQL实战宝典/06 表压缩：不仅仅是空间压缩.md
https://blog.csdn.net/zgaoq/article/details/120522590
https://dev.mysql.com/doc/refman/5.7/en/innodb-page-compression.html
https://dev.mysql.com/doc/refman/5.7/en/innodb-compression-background.html
网上关于这方面资料很多，尤其是姜老师写的最详细，
一、压缩分类
1、COMPRESS 页压缩
2、TPC 压缩
二、自建MySQL环境：
版本：5.7
建表语句：
CREATE TABLE `t1` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` text,
PRIMARY KEY (`id`)
) ENGINE=InnoDB
填充数据：
mysql> insert into t1 select null,repeat('a',200);
Query OK, 1 row affected (0.02 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> insert into t1 select null,repeat('a',200) from t1;
Query OK, 1 row affected (0.02 sec)
Records: 1 Duplicates: 0 Warnings: 0
... 重复执行
mysql> insert into t1 select null,repeat('a',200) from t1;
Query OK, 32768 rows affected (0.50 sec)
Records: 32768 Duplicates: 0 Warnings: 0
mysql> select count(*) from t1;
+----------+
| count(*) |
+----------+
| 65536 |
+----------+
1 row in set (0.04 sec)
三、实验 - COMPRESS页压缩
填充的测试数据几乎都是 'a' ，这种数据应该会有很好的压缩性。
COMPRESS 压缩方式主要针对 Innodb 页进行压缩，将一个 16k (innodb 页默认大小)的页面可压缩为8k、4k、2k、1k，如果不指定 key_block_size 大小，该值默认为页的一半大小，也就是8，默认会将一个 16k 的页面压缩为 8k ，这种场景理论上最多将数据压缩为之前的一半。
操作系统查看文件大小
[root@root ceshi]# du -sh *t1*
12K t1.frm
24M t1.ibd
数据库系统表查看文件大小,注意 FILE_SIZE 和 ALLOCATED_SIZE 字段值是一样的
MySQL [ceshi]> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%ceshi/t1%';
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| 832 | ceshi/t1 | 33 | Barracuda | Dynamic | 16384 | 0 | Single | 4096 | 24117248 | 24121344 |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
1 row in set (0.001 sec)
MySQL [ceshi]> select file_name,total_extents from information_schema.files where file_name like '%ceshi/t1%';
+----------------+---------------+
| file_name | total_extents |
+----------------+---------------+
| ./ceshi/t1.ibd | 23 |
+----------------+---------------+
1 row in set (0.001 sec)
修改 row_format 值，压缩表数据页,注意，默认 key_block_size=8
MySQL [ceshi]> alter table t1 ROW_FORMAT=compressed;
Query OK, 0 rows affected (1.230 sec)
Records: 0 Duplicates: 0 Warnings: 0
MySQL [ceshi]> show create table t1\G
*************************** 1. row ***************************
Table: t1
Create Table: CREATE TABLE `t1` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` text,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=131056 DEFAULT CHARSET=utf8 ROW_FORMAT=COMPRESSED
再次查看文件大小
[root@root ceshi]# du -sh *t1*
12K t1.frm
12M t1.ibd
使用 SQL 查询文件大小
MySQL [ceshi]> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%ceshi/t1%';
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| 833 | ceshi/t1 | 41 | Barracuda | Compressed | 16384 | 8192 | Single | 4096 | 11534336 | 11538432 |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
1 row in set (0.002 sec)
MySQL [ceshi]> select file_name,total_extents from information_schema.files where file_name like '%ceshi/t1%';
+----------------+---------------+
| file_name | total_extents |
+----------------+---------------+
| ./ceshi/t1.ibd | 11 |
+----------------+---------------+
1 row in set (0.001 sec)
从以上结果看，innodb 文件大小为之前的一半，只有 12MB 了。
修改 key_block_size 值为4、2、1 ，分别查看文件大小
MySQL [ceshi]> alter table t1 KEY_BLOCK_SIZE=4;
Query OK, 0 rows affected (1.464 sec)
Records: 0 Duplicates: 0 Warnings: 0
MySQL [ceshi]> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%ceshi/t1%';
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| 834 | ceshi/t1 | 39 | Barracuda | Compressed | 16384 | 4096 | Single | 4096 | 6291456 | 6295552 |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
1 row in set (0.001 sec)
MySQL [ceshi]> select file_name,total_extents from information_schema.files where file_name like '%ceshi/t1%';
+----------------+---------------+
| file_name | total_extents |
+----------------+---------------+
| ./ceshi/t1.ibd | 6 |
+----------------+---------------+
1 row in set (0.001 sec)
MySQL [ceshi]> alter table t1 KEY_BLOCK_SIZE=2;
Query OK, 0 rows affected (1.236 sec)
Records: 0 Duplicates: 0 Warnings: 0
MySQL [ceshi]> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%ceshi/t1%';
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| 835 | ceshi/t1 | 37 | Barracuda | Compressed | 16384 | 2048 | Single | 4096 | 3145728 | 3149824 |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
1 row in set (0.001 sec)
MySQL [ceshi]> select file_name,total_extents from information_schema.files where file_name like '%ceshi/t1%';
+----------------+---------------+
| file_name | total_extents |
+----------------+---------------+
| ./ceshi/t1.ibd | 3 |
+----------------+---------------+
1 row in set (0.001 sec)
MySQL [ceshi]> alter table t1 KEY_BLOCK_SIZE=1;
Query OK, 0 rows affected (2.009 sec)
Records: 0 Duplicates: 0 Warnings: 0
MySQL [ceshi]> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%ceshi/t1%';
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| 836 | ceshi/t1 | 35 | Barracuda | Compressed | 16384 | 1024 | Single | 4096 | 5242880 | 5242880 |
+-------+----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
1 row in set (0.001 sec)
MySQL [ceshi]> select file_name,total_extents from information_schema.files where file_name like '%ceshi/t1%';
+----------------+---------------+
| file_name | total_extents |
+----------------+---------------+
| ./ceshi/t1.ibd | 4 |
+----------------+---------------+
1 row in set (0.002 sec)
小结：
可见并不是 key_block_size 值越小越好。
| key_block_size 值 | 数据文件大小 |
|---|---|
| 不压缩 | 24M |
| 8 | 12M |
| 4 | 6M |
| 2 | 3M |
| 1 | 5M |
三、实验 - TPC表压缩
初始化实验环境，删除重新创建之前的 t1 表；
开始压缩表，并使用 optimize table 命令重建表。
MySQL [ceshi]> alter table t1 COMPRESSION='ZLIB';
Query OK, 0 rows affected (0.011 sec)
Records: 0 Duplicates: 0 Warnings: 0
MySQL [ceshi]> optimize table t1;
+----------+----------+----------+-------------------------------------------------------------------+
| Table | Op | Msg_type | Msg_text |
+----------+----------+----------+-------------------------------------------------------------------+
| ceshi.t1 | optimize | note | Table does not support optimize, doing recreate + analyze instead |
| ceshi.t1 | optimize | status | OK |
+----------+----------+----------+-------------------------------------------------------------------+
2 rows in set (0.604 sec)
操作系统查看文件大小
[root@root ceshi]# du -sh *t1*
12K t1.frm
12M t1.ibd
SQL 查看表大小
MySQL [ceshi]> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%t1%';
+-------+-----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+-----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
| 830 | ceshi/t1 | 33 | Barracuda | Dynamic | 16384 | 0 | Single | 4096 | 24117248 | 12066816 |
+-------+-----------+------+-------------+------------+-----------+---------------+------------+---------------+-----------+----------------+
3 rows in set (0.001 sec)
注意看这两个字段，
FILE_SIZE：文件的表面大小，即未压缩文件大小。(ls -l 结果值)
ALLOCATED_SIZE：文件的实际大小，即磁盘上的文件大小。
从结果看，文件缩小了一半，
还有一些压缩相关参数都是默认值，还没时间去做详细测试。
innodb_compression_level
四、实验 - TPC表压缩（aliyun-rds）
参考文章开头，在云上 RDS 初始化环境。
直接看测试结果吧，
mysql> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%t1%';
+-------+------------------------+------+-------------+------------+-----------+---------------+------------+---------------+------------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+------------------------+------+-------------+------------+-----------+---------------+------------+---------------+------------+----------------+
| 140 | test/t1 | 33 | Barracuda | Dynamic | 16384 | 0 | Single | 4096 | 25165824 | 25120768 |
+-------+------------------------+------+-------------+------------+-----------+---------------+------------+---------------+------------+----------------+
FILE_SIZE 值是24M
开始表级压缩
mysql> alter table t1 COMPRESSION='ZLIB';
Query OK, 0 rows affected (0.02 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> optimize table t1;
+---------+----------+----------+-------------------------------------------------------------------+
| Table | Op | Msg_type | Msg_text |
+---------+----------+----------+-------------------------------------------------------------------+
| test.t1 | optimize | note | Table does not support optimize, doing recreate + analyze instead |
| test.t1 | optimize | status | OK |
+---------+----------+----------+-------------------------------------------------------------------+
2 rows in set (0.37 sec)
mysql> select * from information_schema. INNODB_SYS_TABLESPACES where name like '%t1%';
+-------+------------------------+------+-------------+------------+-----------+---------------+------------+---------------+------------+----------------+
| SPACE | NAME | FLAG | FILE_FORMAT | ROW_FORMAT | PAGE_SIZE | ZIP_PAGE_SIZE | SPACE_TYPE | FS_BLOCK_SIZE | FILE_SIZE | ALLOCATED_SIZE |
+-------+------------------------+------+-------------+------------+-----------+---------------+------------+---------------+------------+----------------+
| 142 | test/t1 | 33 | Barracuda | Dynamic | 16384 | 0 | Single | 4096 | 25165824 | 25120768 |
+-------+------------------------+------+-------------+------------+-----------+---------------+------------+---------------+------------+----------------+
从 FILE_SIZE 结果看，还是24M , 表没有任何变化，如果相同的实验，我放在自建mysql，压缩后大约是12MB。
造成这个的原因也许云上底层文件系统或存储的 block 已经是16kb，这个功能就失去了意义。
标签：name,压缩,ceshi,t1,sec,FILE,mysql,SIZE,小记 From： https://www.cnblogs.com/nanxiang/p/17103240.html