diff --git a/django/db/models/deletion.py b/django/db/models/deletion.py
index 631b455aa35..bc26d82e934 100644
--- a/django/db/models/deletion.py
+++ b/django/db/models/deletion.py
@@ -1,9 +1,9 @@
 from collections import Counter, defaultdict
-from functools import partial
+from functools import partial, reduce
 from itertools import chain
-from operator import attrgetter
+from operator import attrgetter, or_
 
-from django.db import IntegrityError, connections, transaction
+from django.db import IntegrityError, connections, models, transaction
 from django.db.models import query_utils, signals, sql
 
 
@@ -61,6 +61,7 @@ def SET(value):
             collector.add_field_update(field, value, sub_objs)
 
     set_on_delete.deconstruct = lambda: ("django.db.models.SET", (value,), {})
+    set_on_delete.lazy_sub_objs = True
     return set_on_delete
 
 
@@ -68,10 +69,16 @@ def SET_NULL(collector, field, sub_objs, using):
     collector.add_field_update(field, None, sub_objs)
 
 
+SET_NULL.lazy_sub_objs = True
+
+
 def SET_DEFAULT(collector, field, sub_objs, using):
     collector.add_field_update(field, field.get_default(), sub_objs)
 
 
+SET_DEFAULT.lazy_sub_objs = True
+
+
 def DO_NOTHING(collector, field, sub_objs, using):
     pass
 
@@ -93,8 +100,8 @@ class Collector:
         self.origin = origin
         # Initially, {model: {instances}}, later values become lists.
         self.data = defaultdict(set)
-        # {model: {(field, value): {instances}}}
-        self.field_updates = defaultdict(partial(defaultdict, set))
+        # {(field, value): [instances, …]}
+        self.field_updates = defaultdict(list)
         # {model: {field: {instances}}}
         self.restricted_objects = defaultdict(partial(defaultdict, set))
         # fast_deletes is a list of queryset-likes that can be deleted without
@@ -145,10 +152,7 @@ class Collector:
         Schedule a field update. 'objs' must be a homogeneous iterable
         collection of model instances (e.g. a QuerySet).
         """
-        if not objs:
-            return
-        model = objs[0].__class__
-        self.field_updates[model][field, value].update(objs)
+        self.field_updates[field, value].append(objs)
 
     def add_restricted_objects(self, field, objs):
         if objs:
@@ -312,7 +316,8 @@ class Collector:
             if keep_parents and related.model in parents:
                 continue
             field = related.field
-            if field.remote_field.on_delete == DO_NOTHING:
+            on_delete = field.remote_field.on_delete
+            if on_delete == DO_NOTHING:
                 continue
             related_model = related.related_model
             if self.can_fast_delete(related_model, from_field=field):
@@ -340,9 +345,9 @@ class Collector:
                         )
                     )
                     sub_objs = sub_objs.only(*tuple(referenced_fields))
-                if sub_objs:
+                if getattr(on_delete, "lazy_sub_objs", False) or sub_objs:
                     try:
-                        field.remote_field.on_delete(self, field, sub_objs, self.using)
+                        on_delete(self, field, sub_objs, self.using)
                     except ProtectedError as error:
                         key = "'%s.%s'" % (field.model.__name__, field.name)
                         protected_objects[key] += error.protected_objects
@@ -469,11 +474,25 @@ class Collector:
                     deleted_counter[qs.model._meta.label] += count
 
             # update fields
-            for model, instances_for_fieldvalues in self.field_updates.items():
-                for (field, value), instances in instances_for_fieldvalues.items():
+            for (field, value), instances_list in self.field_updates.items():
+                updates = []
+                objs = []
+                for instances in instances_list:
+                    if (
+                        isinstance(instances, models.QuerySet)
+                        and instances._result_cache is None
+                    ):
+                        updates.append(instances)
+                    else:
+                        objs.extend(instances)
+                if updates:
+                    combined_updates = reduce(or_, updates)
+                    combined_updates.update(**{field.name: value})
+                if objs:
+                    model = objs[0].__class__
                     query = sql.UpdateQuery(model)
                     query.update_batch(
-                        [obj.pk for obj in instances], {field.name: value}, self.using
+                        list({obj.pk for obj in objs}), {field.name: value}, self.using
                     )
 
             # reverse instance collections
diff --git a/tests/delete_regress/models.py b/tests/delete_regress/models.py
index dc8658e6c40..cbe6fef3343 100644
--- a/tests/delete_regress/models.py
+++ b/tests/delete_regress/models.py
@@ -90,6 +90,12 @@ class Location(models.Model):
 class Item(models.Model):
     version = models.ForeignKey(Version, models.CASCADE)
     location = models.ForeignKey(Location, models.SET_NULL, blank=True, null=True)
+    location_value = models.ForeignKey(
+        Location, models.SET(42), default=1, db_constraint=False, related_name="+"
+    )
+    location_default = models.ForeignKey(
+        Location, models.SET_DEFAULT, default=1, db_constraint=False, related_name="+"
+    )
 
 
 # Models for #16128
diff --git a/tests/delete_regress/tests.py b/tests/delete_regress/tests.py
index c9d0ff8d0ab..7dccbf555d5 100644
--- a/tests/delete_regress/tests.py
+++ b/tests/delete_regress/tests.py
@@ -399,3 +399,19 @@ class DeleteDistinct(SimpleTestCase):
             Book.objects.distinct().delete()
         with self.assertRaisesMessage(TypeError, msg):
             Book.objects.distinct("id").delete()
+
+
+class SetQueryCountTests(TestCase):
+    def test_set_querycount(self):
+        policy = Policy.objects.create()
+        version = Version.objects.create(policy=policy)
+        location = Location.objects.create(version=version)
+        Item.objects.create(
+            version=version,
+            location=location,
+            location_default=location,
+            location_value=location,
+        )
+        # 3 UPDATEs for SET of item values and one for DELETE locations.
+        with self.assertNumQueries(4):
+            location.delete()