What is "m" in R-Tree height equation?

Question

I got confused with the "m" symbol of R-Tree height (h) equation. What does this "m" represent? Is it minimum entry or Maximum entry? Here is the equation:

where,

N = Number of data objects

h = Maximum value for R-Tree Height

Thanks!

Answer 1

R-trees, like B-trees, have a large branching factor that can be customized based on the block size of the disk or memory they're stored in. This branching factor is M, so the height of the tree is proportional to the base-M logarithm of N.

Hope this helps!

Answer 2

The number of entries of a node (except for the root) in the tree is between m and M, where m lies between [0, M/2]. Also, M is the maximum number of entries in a node, and it may differ for leaf and non-leaf nodes.