mysql - how the mysql realize the multiple column index(union index)? what's the datastructure of the multiple column index

Question

yeah，we know that the mysql use the B+ tree to realize the index。 And, you can create union index(multiple column index) on the table.

I want to know how the MySql realize the multiple index, what the structure of the data?

Answer 1

一个 B+ 树，所有列值以适当的顺序连接到键中。