Finally understand that MySQL index needs to use B+tree, and it is so fast

The mysql tutorial column introduces the B+tree for understanding indexes.

Tip : When there are two middle keywords, the left keyword is usually split up.

Delete

The delete operation will be more troublesome than the search and insert, because the keyword to be deleted may be on the leaf node, or It may not be there, and the deletion may cause the imbalance of the B-tree, and operations such as merging and rotation are required to maintain the balance of the whole tree.

Take a random tree (level 5) as an example

The above is the final understanding that the MySQL index uses B+tree, and it is so fast. For more details, please pay attention to other related articles on 1024programmer.com !