Ññûëêè:
https://habr.com/ru/post/114154/
https://sqlhints.com/tag/index-b-tree-structure/
https://www.sqlshack.com/top-25-sql-interview-questions-and-answers-about-indexes/
https://www.sqlhammer.com/the-b-in-b-tree-indexing-sql-server/