MySQL data interface why use B+ tree

Hsh table: The hash table cannot perform range lookup.

Balanced binary tree: Balanced binary tree can perform range query, but the greater the data volume, the greater the height of the tree, the query speed will also be reduced. Range queries also need to be repeated, the speed is very slow.

B tree: B tree can put two numbers together, which can solve the problem that the height of the balanced tree is too high, but there is still a roundabout problem

B + tree: B+ tree not only inherits the structure of B tree, but also orderly connects all trees through leaf nodes, which solves the problem of B tree cyclotron