INNODB 独享表空间包括
数据，索引，插入缓存，数据字典。共享表空间包括：Undo信息（不会回收<物理空间上>），双写缓存信息，事务信息等。
完整的innodb结构包括
段（segment）：组成表空间，有区组成。
区（extent）：有64个连续的页组成。每个页16K，总共1M。对于大的数据段，每次最后可申请4个区。
页（page）：是INNODB 磁盘管理的单位，有行组成。
行（row）：包括事务ID，回滚指针，列信息等。
建立测试表
CREATE TABLE `tt` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(10) DEFAULT NULL,
`age` int(11) DEFAULT NULL,
`address` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=823 DEFAULT CHARSET=utf8;
python py_innodb_page_info.py ../../run5724/data/t2/tt.ibd -v
page offset 00000000, page type <File Space Header>
page offset 00000001, page type <Insert Buffer Bitmap>
page offset 00000002, page type <File Segment inode>
page offset 00000003, page type <B-tree Node>, page level <0000>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
Total number of page: 6: //总共６个page
Freshly Allocated Page: 2 //两个空闲page
Insert Buffer Bitmap: 1
File Space Header: 1
B-tree Node: 1 //一个数据page
File Segment inode: 1
ls -lh tt.ibd
-rw-rw---- 1 mysql mysql 96K 2012-10-17 14:26 tt.ibd
得到的信息是表初始化大小为96K，他是有 Total number of page * 16 得来的。1个数据页，2个可用页面(Freshle Allocated Page)。
为什么没有申请区？
区是64个连续的页，大小1M。那么表大小也应该是至少1M。但是现在只有96K（默认）。原因是因为每个段开始的时候，
先有32个页大小的碎片页存放数据，使用完之后才是64页的连续申请，最多每次可以申请4个区，保证数据的顺序。
这里看出表大小增加是按照至少64页的大小的空间来增加的，即1M增加。
随便写点数据进去
insert into tt(name,age,address) values('aaa',23,'HZZZ');
编辑为sql文件，凑成大约五百行，然后进去执行source
ls -lht ../../run5724/data/t2/tt.ibd
-rw-r----- 1 liuzhuan liuzhuan 128K 3月 17 16:40 ../../run5724/data/t2/tt.ibd
超出了96k，看看发生了什么
python py_innodb_page_info.py ../../run5724/data/t2/tt.ibd -v
page offset 00000000, page type <File Space Header>
page offset 00000001, page type <Insert Buffer Bitmap>
page offset 00000002, page type <File Segment inode>
page offset 00000003, page type <B-tree Node>, page level <0001> //空闲page 1上的偏移位置
page offset 00000004, page type <B-tree Node>, page level <0000>
page offset 00000005, page type <B-tree Node>, page level <0000>
page offset 00000006, page type <B-tree Node>, page level <0000>
page offset 00000000, page type <Freshly Allocated Page> //还有另外一个空闲page
Total number of page: 8:
Freshly Allocated Page: 1
Insert Buffer Bitmap: 1
File Space Header: 1
B-tree Node: 4 //四个数据page
File Segment inode: 1
反复执行source sql文件
python py_innodb_page_info.py ../../run5724/data/t2/tt.ibd -v
page offset 00000000, page type <File Space Header>
page offset 00000001, page type <Insert Buffer Bitmap>
page offset 00000002, page type <File Segment inode>
page offset 00000003, page type <B-tree Node>, page level <0001>
page offset 00000004, page type <B-tree Node>, page level <0000>
page offset 00000005, page type <B-tree Node>, page level <0000>
page offset 00000006, page type <B-tree Node>, page level <0000>
page offset 00000007, page type <B-tree Node>, page level <0000>
page offset 00000008, page type <B-tree Node>, page level <0000>
page offset 00000009, page type <B-tree Node>, page level <0000>
page offset 0000000a, page type <B-tree Node>, page level <0000>
page offset 0000000b, page type <B-tree Node>, page level <0000>
page offset 0000000c, page type <B-tree Node>, page level <0000>
page offset 0000000d, page type <B-tree Node>, page level <0000>
page offset 00000000, page type <Freshly Allocated Page> //另外一个16k的空闲page
Total number of page: 15:
Freshly Allocated Page: 1
Insert Buffer Bitmap: 1
File Space Header: 1
B-tree Node: 11
File Segment inode: 1
page总数变为15个，11个数据page，另外一个16k的空闲page还没用到
反复执行source sql文件，填充满另外一个空闲page，让mysql开辟新的区（64个page，每个page 16k）
source /home/liuzhuan/wintrust23/tt.sql
ls -lht ../../run5724/data/t2/tt.ibd
-rw-r----- 1 liuzhuan liuzhuan 576K 3月 17 17:10 ../../run5724/data/t2/tt.ibd
liuzhuan@liuzhuan-simos:~/wintrust23/mysql-utils-tool/py_innodb_page_info$ python py_innodb_page_info.py ../../run5724/data/t2/tt.ibd -v
page offset 00000000, page type <File Space Header> //文件头空间页
page offset 00000001, page type <Insert Buffer Bitmap> //插入缓存位图页
page offset 00000002, page type <File Segment inode> //文件段节点
page offset 00000003, page type <B-tree Node>, page level <0001> //根page
page offset 00000004, page type <B-tree Node>, page level <0000>
page offset 00000005, page type <B-tree Node>, page level <0000>
page offset 00000006, page type <B-tree Node>, page level <0000>
page offset 00000007, page type <B-tree Node>, page level <0000>
page offset 00000008, page type <B-tree Node>, page level <0000>
page offset 00000009, page type <B-tree Node>, page level <0000>
page offset 0000000a, page type <B-tree Node>, page level <0000>
page offset 0000000b, page type <B-tree Node>, page level <0000>
page offset 0000000c, page type <B-tree Node>, page level <0000>
page offset 0000000d, page type <B-tree Node>, page level <0000>
page offset 0000000e, page type <B-tree Node>, page level <0000>
page offset 0000000f, page type <B-tree Node>, page level <0000>
page offset 00000010, page type <B-tree Node>, page level <0000>
page offset 00000011, page type <B-tree Node>, page level <0000>
page offset 00000012, page type <B-tree Node>, page level <0000>
page offset 00000013, page type <B-tree Node>, page level <0000>
page offset 00000014, page type <B-tree Node>, page level <0000>
page offset 00000015, page type <B-tree Node>, page level <0000>
page offset 00000016, page type <B-tree Node>, page level <0000>
page offset 00000017, page type <B-tree Node>, page level <0000>
page offset 00000018, page type <B-tree Node>, page level <0000>
page offset 00000019, page type <B-tree Node>, page level <0000>
page offset 0000001a, page type <B-tree Node>, page level <0000>
page offset 0000001b, page type <B-tree Node>, page level <0000>
page offset 0000001c, page type <B-tree Node>, page level <0000>
page offset 0000001d, page type <B-tree Node>, page level <0000>
page offset 0000001e, page type <B-tree Node>, page level <0000>
page offset 0000001f, page type <B-tree Node>, page level <0000>
page offset 00000020, page type <B-tree Node>, page level <0000>
page offset 00000021, page type <B-tree Node>, page level <0000>
page offset 00000022, page type <B-tree Node>, page level <0000>
page offset 00000000, page type <Freshly Allocated Page>
Total number of page: 36:
Freshly Allocated Page: 1
Insert Buffer Bitmap: 1
File Space Header: 1
B-tree Node: 32
File Segment inode: 1
一共36个page，36*16就是文件大小，符合576K的size设定，更细的换算就是[32(空闲page)*16=512K + 4(结构page)*16=64]
这里开始要是再插入的话，应该申请最少1M的页（64*16 新的区）
ls -lht ../../run5724/data/t2/tt.ibd
-rw-r----- 1 liuzhuan liuzhuan 2.0M 3月 17 17:15 ../../run5724/data/t2/tt.ibd
python py_innodb_page_info.py ../../run5724/data/t2/tt.ibd -v
page offset 00000000, page type <File Space Header>
page offset 00000001, page type <Insert Buffer Bitmap>
page offset 00000002, page type <File Segment inode>
page offset 00000003, page type <B-tree Node>, page level <0001>
page offset 00000004, page type <B-tree Node>, page level <0000>
page offset 00000005, page type <B-tree Node>, page level <0000>
page offset 00000006, page type <B-tree Node>, page level <0000>
page offset 00000007, page type <B-tree Node>, page level <0000>
page offset 00000008, page type <B-tree Node>, page level <0000>
page offset 00000009, page type <B-tree Node>, page level <0000>
page offset 0000000a, page type <B-tree Node>, page level <0000>
page offset 0000000b, page type <B-tree Node>, page level <0000>
page offset 0000000c, page type <B-tree Node>, page level <0000>
page offset 0000000d, page type <B-tree Node>, page level <0000>
page offset 0000000e, page type <B-tree Node>, page level <0000>
page offset 0000000f, page type <B-tree Node>, page level <0000>
page offset 00000010, page type <B-tree Node>, page level <0000>
page offset 00000011, page type <B-tree Node>, page level <0000>
page offset 00000012, page type <B-tree Node>, page level <0000>
page offset 00000013, page type <B-tree Node>, page level <0000>
page offset 00000014, page type <B-tree Node>, page level <0000>
page offset 00000015, page type <B-tree Node>, page level <0000>
page offset 00000016, page type <B-tree Node>, page level <0000>
page offset 00000017, page type <B-tree Node>, page level <0000>
page offset 00000018, page type <B-tree Node>, page level <0000>
page offset 00000019, page type <B-tree Node>, page level <0000>
page offset 0000001a, page type <B-tree Node>, page level <0000>
page offset 0000001b, page type <B-tree Node>, page level <0000>
page offset 0000001c, page type <B-tree Node>, page level <0000>
page offset 0000001d, page type <B-tree Node>, page level <0000>
page offset 0000001e, page type <B-tree Node>, page level <0000>
page offset 0000001f, page type <B-tree Node>, page level <0000>
page offset 00000020, page type <B-tree Node>, page level <0000>
page offset 00000021, page type <B-tree Node>, page level <0000>
page offset 00000022, page type <B-tree Node>, page level <0000>
page offset 00000023, page type <B-tree Node>, page level <0000>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000040, page type <B-tree Node>, page level <0000>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
page offset 00000000, page type <Freshly Allocated Page>
Total number of page: 128:
Freshly Allocated Page: 91
Insert Buffer Bitmap: 1
File Space Header: 1
B-tree Node: 34
File Segment inode: 1
page总数从36跳到了128，因为已经用完了32个碎片页，新的page会采用区的方式进行空间申请。信息中看到有很多空闲page(凑成了一个区)，正好说明这点