使用 innodb_ruby 探索 InnoDB 页面管理

[This post refers to innodb_ruby version 0.8.8 as of February 3, 2014.]

[此帖子是根据2014年2月3日的innodb_ruby版本0.8.8撰写的。]

In On learning InnoDB: A journey to the core I introduced a new library and command-line tool in the innodb_ruby project. Later on in A quick introduction to innodb_ruby I walked through installation and a few quick demos of the innodb_space command-line tool.

在学习InnoDB：一次到核心的旅程中，我介绍了innodb_ruby项目中的一个新库和命令行工具。稍后在innodb_ruby的快速介绍中，我介绍了安装和使用innodb_space命令行工具的一些快速演示。

In my last post, Page management in InnoDB space files, I described InnoDB’s extent, file segment, and free space management structures. Now I will provide a few demonstrations of using innodb_space to examine those structures in real tables.

在我上一篇文章中，InnoDB空间文件中的页面管理，我描述了InnoDB的范围、文件段和空闲空间管理结构。现在我将提供一些使用innodb_space来检查这些结构在实际表中的演示。

A minimal, empty table

一个最小的空表

I created an empty table (the schema doesn’t matter) to illustrate the “minimal” state of InnoDB’s page management structures. The space-page-type-regions mode will summarize the type of all contiguous regions of the same page type:

我创建了一个空表（模式无关紧要），以说明InnoDB页面管理结构的“最小”状态。空间-页面类型-区域模式将总结相同页面类型的所有连续区域的类型：

$ innodb_space -f test/e.ibd space-page-type-regions start end count type
0 0 1 FSP_HDR
1 1 1 IBUF_BITMAP
2 2 1 INODE
3 3 1 INDEX
4 5 2 FREE (ALLOCATED)

$ innodb_space -f test/e.ibd space-page-type-regions start end count type
0 0 1 FSP_HDR
1 1 1 IBUF_BITMAP
2 2 1 INODE
3 3 1 INDEX
4 5 2 FREE (ALLOCATED)

The table has allocated the standard pages for IBD space files: FSP_HDR, IBUF_BITMAP, INODE, and an INDEX page for the root of the (empty) index. There are also two FREE (ALLOCATED) pages which are unused.

该表已为IBD空间文件分配了标准页面：FSP_HDR、IBUF_BITMAP、INODE以及...