Removed items

The following table shows the removed items:

Item	Type	Notes
mongoperf	Binary	Used to measure disk I/O performance without having to enter a mongo shell or otherwise access MongoDB.
$isolated	Operator	This operator was used in previous versions of MongoDB during update operations to prevent multidocument updates from being read until all changes took place. MongoDB 4.x uses transaction support instead. Any commands that include this operator need to be rewritten.