B tree and b+tree of MySQL

p Is a pointer , Purple numbers are clustered indexes ,data Is line record information

B tree The index values are stored as follows ：

B+tree Only leaf nodes are stored data data

summary ：

The size of a disk block is 16kb, Limited data stored , If saved data Data words , A disk block cannot store several pieces of data

B+tree The amount of data that can be stored is tens of millions （ Primary key id yes int In the case of self increasing ）

B+tree Usually as long as 3 to 4 layer