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一、存储模型
MySQL
Each tablespace consists of database pages with a default size of 16KB. The pages are grouped into extents of size 1MB (64 consecutive pages). The “files” inside a tablespace are called segments in InnoDB.
Two segments are allocated for each index in InnoDB. One is for nonleaf nodes of the B-tree, the other is for the leaf nodes. Keeping the leaf nodes contiguous on disk enables better sequential I/O operations, because these leaf nodes contain the actual table data.
- 表空间Tablespace(ibd文件)
- 段Segment(一个索引2个段)
- 区Extent(1MB):64个Page
- 页Page(16KB):磁盘管理的最小单位
从示意图可以清晰的了解到MySQL的行数据Ro