How about index reorganization?

Till now i haven’t seen a topic related to this.

My question is twofold.

How can we determine that an B*Tree index should be reorganized ?
and how it can be done ? About this the only way is to drop and recreate the index.

@JOEL_91907

What Lab or Lecture is this related to? If this is just a general question, this Forum is not the correct place to ask this. Instead post this on one of the MongoDB general forums or on StackOverflow.