Mysql的索引是什么结构

Question

我在网上无数起看到文章说Mysql的索引采用B+树（当然还有别的我们这里只讨论B+树），但是我看Mysql的官方文当里面并没有用B+ tree而是用的B-tree我相信Mysql的权威文档不会犯如此低级的错误。所以网上说使用B+树的根据是什么？

附上官方文档mysql索引第二段

Most MySQL indexes (`PRIMARY KEY`, `UNIQUE`, `INDEX`, and `FULLTEXT`) are stored in [B-trees](https://dev.mysql.com/doc/refman/8.0/en/glossary.html#glos_b_tree "B-tree")

Answer 1

The use of the term B-tree is intended as a reference to the general class of index design. B-tree structures used by MySQL storage engines may be regarded as variants due to sophistications not present in a classic B-tree design.

我看文档上的解释，B-tree一词应该包含了题主所说的B+树和B-tree。