Release Notes for MongoDB 8.1
On this page
Warning
MongoDB 8.1 Not Yet Available
MongoDB 8.1 release candidates are not yet available. This version of the manual is for an upcoming release and is currently a work in progress.
Important
MongoDB 8.1 is a rapid release and is only supported for MongoDB Atlas. MongoDB 8.1 is not supported for use on-premises. For more information, see MongoDB Versioning.
To install the latest MongoDB version supported for on-premises use, MongoDB 8.0, see the MongoDB 8.0 installation instructions.
Security
$lookup Support for Encrypted Collections
Starting in MongoDB 8.1, you can reference multiple encrypted collections in a
$lookup stage.
To learn more, see:
General Changes
Query Statistics
Starting in MongoDB 8.1, query statistics are collected and reported for
count and distinct commands. For details, see
count Command Query Shape and
distinct Command Query Shape.
serverStatus Metrics
Starting in MongoDB 8.1 (and 8.0.4 and 7.0.14), the indexStats
section of the serverStatus command output tracks indexes in
prepareUnique state.
Add Comments to Query Settings
Starting in MongoDB 8.1 (and 8.0.4), you can use
setQuerySettings to add comments to query settings. For
example, add a comment that indicates why you added query settings.