olemus
m-aarne puu muutuva, kuid sageli suure tipujärglaste arvuga
= a m-ary tree with a variable but often large number of children per node

ülevaateid
https://en.wikipedia.org/wiki/B%2B_tree
https://www.studytonight.com/advanced-data-structures/b-plus-trees-data-structure
https://medium.com/beuni/b-tree-and-b-tree-d27a9cd3630b