"The deeper the tree, the slower it is to look up elements. Thus, we want shallow trees for our databases!"
With composite indices in InnoDB it's even more important to keep the tree streamlined and let it fan out according to data cardinality: https://news.ycombinator.com/item?id=34404641
With composite indices in InnoDB it's even more important to keep the tree streamlined and let it fan out according to data cardinality: https://news.ycombinator.com/item?id=34404641