23 lines
250 B
Markdown
23 lines
250 B
Markdown
|
# B+ Tree 索引
|
||
|
|
|
||
|
|
## 适用
|
||
|
|
|
||
|
|
- 主键索引
|
||
|
|
- 叶子结点存放具体数据
|
||
|
|
- 二级索引
|
||
|
|
- 叶子结点存放主键值
|
||
|
|
- 回表主键索引
|
||
|
|
|
||
|
|
## B+ vs B
|
||
|
|
|
||
|
|
- 基于范围
|
||
|
|
- 数据量小
|
||
|
|
|
||
|
|
## B+ vs 二叉
|
||
|
|
|
||
|
|
- 深度
|
||
|
|
|
||
|
|
## B+ vs Hash
|
||
|
|
|
||
|
|
- 等值查询
|