Hi @steevej,
thanks for your response.
That’s fine since that means when the updateMany() is finished all matched documents match the expected state regarding the update.
In this case the difference between matchedCount and modifiedCount is fine.
And how do I find out which one it is?
In fact that is only relevant for me if this would mean that one or more documents could not be updated for some other reason than you mentioned. Meaning that updating a document failed and it does not match the expected update state.