Today in MongoDB we capture transaction metrics that allow us to understand the number of transactions that have occurred over a period of time for a given cluster. 

In addition to the counters it would be useful to understand how the transaction was used by capturing high level information on the documents and collections targeted by a given transaction.

Would be helpful to categorize the transaction "shape" be capturing counters for how often different transaction shapes are used:

• Single Document Transaction
  • Single Document Read-Only
  • Single Document Write
• Multiple Documents within the Same Collection
  • Multi-Document Read-Only within the Same Collection
  • Multi-Document Write Single Document within the Same Collection
  • Multi-Document Write Multiple Documents within the Same Collection
• Multiple Documents within the Different Collection 
  • Multi-Document Read-Only across Multiple Collections
  • Multi-Document Write Single Document across Multiple Collections
  • Multi-Document Write Multiple Documents across Multiple Collections