DOCSP-24216 aggregation update (#1572) (#1583)

jason-price-mongodb · jason-price-mongodb · web-flow · commit 7ce19b7e85ef · 2022-08-04T15:35:39.000-07:00
* DOCSP-24216-aggregation-update * DOCSP-24216-aggregation-update * DOCSP-24216-aggregation-update * DOCSP-24216-aggregation-update * DOCSP-24216-aggregation-update * DOCSP-24216-aggregation-update Co-authored-by: jason-price-mongodb <jshfjghsdfgjsdjh@aolsdjfhkjsdhfkjsdf.com> Co-authored-by: jason-price-mongodb <jshfjghsdfgjsdjh@aolsdjfhkjsdhfkjsdf.com>
diff --git a/source/includes/aggregation-pipeline-introduction.rst b/source/includes/aggregation-pipeline-introduction.rst
@@ -11,6 +11,13 @@ An aggregation pipeline consists of one or more :ref:`stages
 - An aggregation pipeline can return results for groups of documents.
   For example, return the total, average, maximum, and minimum values.
 
-Starting in MongoDB 4.2, you can also update documents with an
-aggregation pipeline. See
+Starting in MongoDB 4.2, you can update documents with an aggregation
+pipeline if you use the stages shown in
 :doc:`/tutorial/update-documents-with-aggregation-pipeline`.
+
+.. note::
+
+   Aggregation pipelines run with the
+   :method:`db.collection.aggregate()` method do not modify documents in
+   a collection, unless the pipeline contains a :pipeline:`$merge` or
+   :pipeline:`$out` stage.
