B+Tree
http://blog.codinglabs.org/articles/theory-of-mysql-index.html
https://www.cnblogs.com/nullzx/p/8729425.html
索引
https://juejin.im/post/5e6509fd518825490d1267eb
mysql b+树能存多少条数据？b+树每层有多少分支？
https://blog.csdn.net/csdnlijingran/article/details/102309593
InnoDB一棵B+树可以存放多少行数据？
https://www.cnblogs.com/leefreeman/p/8315844.html
终于有篇看的懂的B树文章了！
https://database.51cto.com/art/201911/605881.htm
理解InnoDB的聚集索引（译）
https://www.jianshu.com/p/2879225ba243
我以为我对Mysql索引很了解，直到我遇到了阿里的面试官
https://www.hollischuang.com/archives/3818
曾经，我以为我很懂MySQL索引...
https://www.modb.pro/db/29681
深入理解MySQL索引
https://www.infoq.cn/article/OJKWYykjoyc2YGB0Sj2c
一张图搞懂MySQL的索引失效
https://segmentfault.com/a/1190000021464570
联合索引在B+树上的存储结构及数据查找方式
https://blog.csdn.net/ibigboy/article/details/104571930?depth_1-
MySQL索引背后的数据结构及算法原理
http://blog.codinglabs.org/articles/theory-of-mysql-index.html
mysql b+树能存多少条数据？b+树每层有多少分支？
https://blog.csdn.net/csdnlijingran/article/details/102309593
MySQL Explain详解
https://www.cnblogs.com/xuanzhi201111/p/4175635.html
MySQL 性能优化神器 Explain 使用分析
https://segmentfault.com/a/1190000008131735
聚集索引
https://www.cnblogs.com/aspnethot/articles/1504082.html
https://www.jianshu.com/p/2879225ba243
覆盖索引
https://segmentfault.com/a/1190000021718016
MySql 索引优化
https://blog.csdn.net/codejas/article/details/78632876
MySQL如何利用索引优化ORDER BY排序语句
https://blog.csdn.net/ryb7899/article/details/5580624
MySql ORDER BY 索引优化
https://blog.csdn.net/codejas/article/details/78632901
MySQL 索引存储顺序和 order by 不一致，怎么办？
https://www.infoq.cn/article/fD5ZV2urHCuhqlYvXRd0
ORDER BY 优化
https://dev.mysql.com/doc/refman/8.0/en/order-by-optimization.html
https://www.docs4dev.com/docs/zh/mysql/5.7/reference/order-by-optimization.html
https://zhuanlan.zhihu.com/p/79026015
https://blog.csdn.net/hguisu/article/details/7161981
GROUP BY 优化
https://www.docs4dev.com/docs/zh/mysql/5.7/reference/group-by-optimization.html#group-by-%E4%BC%98%E5%8C%96
