DOCS-13951 Aggregation pipeline length limit

Author: jason-price-mongodb

source/core/aggregation-pipeline-limits.txt

@@ -31,6 +31,14 @@ The limit only applies to the returned documents; during the pipeline
 processing, the documents may exceed this size. The
 :method:`db.collection.aggregate()` method returns a cursor by default.
 
+Number of Stages Restrictions
+-----------------------------
+
+.. versionchanged:: 5.0
+
+MongoDB 5.0 limits the number of :doc:`aggregation pipeline stages
+</reference/operator/aggregation-pipeline>` allowed in a single pipeline
+to 1000.
 
 .. _agg-memory-restrictions:
 

source/release-notes/5.0-compatibility.txt

@@ -61,6 +61,10 @@ General Changes
   :method:`db.collection.reIndex()` shell method may only be run on
   :term:`standalone` instances.
 
+- Starting in MongoDB 5.0, the number of :doc:`aggregation pipeline
+  stages </reference/operator/aggregation-pipeline>` allowed in a single
+  pipeline is limited to 1000.
+
 Deprecations
 ~~~~~~~~~~~~