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mysql InnoDB数据页结构Page Header
by fyang 02 Mar 2015 08:17
| Bytes | Name | |
| 2 | PAGE_N_DIR_SLOTS | number of slots in page directory |
| 2 | PAGE_HEAP_TOP | pointer to record heap top |
| 2 | PAGE_N_HEAP | number of records in the heap |
| 2 | PAGE_FREE | pointer to start of page free record list |
| 2 | PAGE_GARBAGE | number of bytes in deleted records (delete flag 1) |
| 2 | PAGE_LAST_INSERT | pointer to the last inserted record |
| 2 | PAGE_DIRECTION | last insert direction: PAGE_LEFT, … |
| 2 | PAGE_N_DIRECTION | number of consecutive inserts to the direction |
| 2 | PAGE_N_RECS | number of user records on the page |
| //8 | PAGE_MAX_TRX_ID | highest id of a trx which may have modified |
| //0 | PAGE_HEADER_PRIV_END | end of private data structure of the page |
| 2 | PAGE_LEVEL | level of the node in an index tree, 0 means leaf |
| 8 | PAGE_INDEX_ID | index id where the page belongs. |
| 10 | PAGE_BTR_SEG_LEAF | only when root page, segment begin pointer |
| 10 | PAGE_BTR_SEG_TOP | only when root page, segment begin pointer |
| //10 | PAGE_BTR_IBUF_FREE_LIST | |
| //10 | PAGE_BTR_IBUF_FREE_LIST_NODE |
mysql InnoDB 文件数据页File Header结构
by fyang 02 Mar 2015 08:16
Fields
Bytes Name
4 FIL_PAGE_SPACE_OR_CHKSUM (in < MySQL-4.0.14 tablespace id, otherwise checksum)
4 FIL_PAGE_OFFSET (offset in tablespace)
4 FIL_PAGE_PREV
4 FIL_PAGE_NEXT
8 FIL_PAGE_LSN (lsn of the end of the newest modification)
2 FIL_PAGE_TYPE
8 FIL_PAGE_FILE_FLUSH_LSN
4 FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID
mysql InnoDB数据页结构
by fyang 21 Feb 2015 15:32
![[mysql-innodb]4-6-data-page-format.png](http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]4-6-data-page-format.png)
http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]4-6-data-page-format.png
mysql Char的存储
by fyang 21 Feb 2015 15:30
MySQL 4.1开始CHR(N)是字符长度
- 验证
- char_length(str)
- length(str)
- hex(str)
- 在可变长字符集中(gbk, utf8等)，char是作为可变长类型存储
mysql innodb redundant行格式
by fyang 21 Feb 2015 09:41
![[mysql-innodb]4-3-row-structure-format-compact.png](http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]4-3-row-structure-format-compact.png)
http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]4-3-row-structure-format-compact.png
mysql innodb compact行格式
by fyang 21 Feb 2015 09:27
![[mysql-innodb]4-2-row-structure-format-compact.png](http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]4-2-row-structure-format-compact.png)
http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]4-2-row-structure-format-compact.png
![[mysql-innodb]4-1-storage-logical-structure.png](http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]4-1-storage-logical-structure.png)
![[mysql-innodb]3-1-file-per-file.png](http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]3-1-file-per-file.png)
![[mysql-innodb]3-2-logroups.png](http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]3-2-logroups.png)
![[mysql-innodb]3-3-writing-redolog.png](http://7vzpyg.com1.z0.glb.clouddn.com/[mysql-innodb]3-3-writing-redolog.png)
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