Updated yield, fixed lints, rewrote docs to speak more high-level

Author: Jibola

django_mongodb_backend/compiler.py

@@ -18,9 +18,6 @@
 
 from .query import MongoQuery, wrap_database_errors
 
-# Maximum document batch size for MongoDB cursor responses.
-MAX_BATCH_SIZE_MB = 1024 * 1024 * 16
-
 
 class SQLCompiler(compiler.SQLCompiler):
     """Base class for all Mongo compilers."""
@@ -321,15 +318,13 @@ def _make_result(self, entity, columns):
     def cursor_iter(self, cursor, _, columns):
         """
         Yield chunks of results from cursor.
-        MongoDB ignores all chunk_size overrides. Cursor iteration abides by
-        MongoDB's default cursor batch size response.
+        Ignore any chunk_size/batch_size overrides and abide by MongoDB's
+        default chunking behavior. This maximizes performance on document
+        retrieval.
         Read more here: https://www.mongodb.com/docs/manual/core/cursors/#cursor-batches
         """
-        chunk = []
-
         for row in cursor:
-            chunk.append(self._make_result(row, columns))
-        return chunk
+            yield [self._make_result(row, columns)]
 
     def check_query(self):
         """Check if the current query is supported by the database."""

django_mongodb_backend/query.py

@@ -76,8 +76,7 @@ def get_cursor(self):
         """
         self.compiler.connection.validate_no_broken_transaction()
         return self.compiler.collection.aggregate(
-            self.get_pipeline(),
-            session=self.compiler.connection.session,
+            self.get_pipeline(), session=self.compiler.connection.session
         )
 
     def get_pipeline(self):

docs/source/releases/5.1.x.rst

@@ -7,13 +7,18 @@ Django MongoDB Backend 5.1.x
 
 *Unreleased*
 
+
+Bug fixes
+---------
+
 - Fixed crash when loading models with a null value for ``ArrayField``\s where
   the ``base_field`` uses a database converter.
 - Fixed ``RecursionError`` when using ``Trunc`` database functions on non-MongoDB
   databases.
-- Removed ``GET_ITERATOR_CHUNK_SIZE`` as default from
-  :meth:`SQLCompiler.execute_sql() <django_mongodb_backend.compiler.SQLCompiler.execute_sql>`.
-  Cursor iteration will now use MongoDB default batch sizing.
+- Removed user configurable request chunking. Allowing MongoDB to
+  handle chunking automatically improves performance and reduces complexity.
+  As a result, :meth:`QuerySet.iterator() <django.db.models.query.QuerySet.iterator>`
+  ignores the ``chunk_size`` parameter.
 
 
 5.1.0 beta 3

docs/source/releases/5.2.x.rst

@@ -24,9 +24,10 @@ Bug fixes
   databases.
 - :meth:`QuerySet.explain() <django.db.models.query.QuerySet.explain>` now
   :ref:`returns a string that can be parsed as JSON <queryset-explain>`.
-- Removed ``GET_ITERATOR_CHUNK_SIZE`` as default from
-  :meth:`SQLCompiler.execute_sql() <django_mongodb_backend.compiler.SQLCompiler.execute_sql>`.
-  Cursor iteration will now use MongoDB default batch sizing.
+- Removed user configurable request chunking. Allowing MongoDB to
+  handle chunking automatically improves performance and reduces complexity.
+  As a result, :meth:`QuerySet.iterator() <django.db.models.query.QuerySet.iterator>`
+  ignores the ``chunk_size`` parameter.
 
 
 5.2.0 beta 1