Support '__all__' in no_db_index to exclude all fields from indexing in the Historical Model

AUTHORS.rst

@@ -147,6 +147,7 @@ Authors
 - `Sridhar Marella <https://github.com/sridhar562345>`_
 - `Mattia Fantoni <https://github.com/MattFanto>`_
 - `Trent Holliday <https://github.com/trumpet2012>`_
+- Raja Rehan Ahmed (`rajarehanahmed <https://github.com/rajarehanahmed>`_)
 
 Background
 ==========

CHANGES.rst

@@ -5,6 +5,8 @@ Unreleased
 ----------
 
 - Tests are no longer bundled in released wheels (gh-1478)
+- ``no_db_index`` in RecordModels model now supports ```"__all__"`` in order to drop all
+  indices in the historical model (gh-1491)
 
 3.9.0 (2025-01-26)
 ------------------

docs/historical_model.rst

@@ -519,6 +519,28 @@ And you don't want to create database index for ``question``, it is necessary to
         history = HistoricalRecords(no_db_index=['question'])
 
 
+A single field can also be passed as a string instead of a list:
+
+.. code-block:: python
+
+    class PollWithExcludeFields(models.Model):
+        question = models.CharField(max_length=200, db_index=True)
+
+        history = HistoricalRecords(no_db_index='question')
+
+
+It is also possible to exclude all fields from having database indices in the historical table
+by using __all__:
+
+.. code-block:: python
+
+    class PollWithExcludeFields(models.Model):
+        question = models.CharField(max_length=200, db_index=True)
+        published_at = models.DateTimeField(auto_now_add=True, db_index=True)
+
+        history = HistoricalRecords(no_db_index='__all__')
+
+
 By default, django-simple-history keeps all indices. and even forces them on unique fields and relations.
 WARNING: This will drop performance on historical lookups
 

simple_history/models.py

@@ -83,6 +83,9 @@ def _history_user_setter(historical_instance, user):
         historical_instance.history_user_id = user.pk
 
 
+ALL_FIELDS = "__all__"
+
+
 class HistoricalRecords:
     DEFAULT_MODEL_NAME_PREFIX = "Historical"
 
@@ -142,7 +145,7 @@ def __init__(
         self.m2m_fields = m2m_fields
         self.m2m_fields_model_field_name = m2m_fields_model_field_name
 
-        if isinstance(no_db_index, str):
+        if isinstance(no_db_index, str) and no_db_index != ALL_FIELDS:
             no_db_index = [no_db_index]
         self.no_db_index = no_db_index
 
@@ -402,7 +405,7 @@ def copy_fields(self, model):
                 transform_field(field)
 
             # drop db index
-            if field.name in self.no_db_index:
+            if self.no_db_index == ALL_FIELDS or field.name in self.no_db_index:
                 field.db_index = False
 
             fields[field.name] = field

simple_history/tests/models.py

@@ -925,6 +925,15 @@ class ModelWithMultipleNoDBIndex(models.Model):
     history = HistoricalRecords(no_db_index=["name", "fk", "other"])
 
 
+class ModelWithAllNoDBIndex(models.Model):
+    name = models.CharField(max_length=15, db_index=True)
+    name_no_index = models.CharField(max_length=15)
+    fk = models.ForeignKey(
+        "Library", on_delete=models.CASCADE, null=True, related_name="+"
+    )
+    history = HistoricalRecords(no_db_index="__all__")
+
+
 class TestOrganization(models.Model):
     name = models.CharField(max_length=15, unique=True)
 

simple_history/tests/tests/test_models.py

@@ -73,6 +73,7 @@
     InheritedRestaurant,
     Library,
     ManyToManyModelOther,
+    ModelWithAllNoDBIndex,
     ModelWithCustomAttrOneToOneField,
     ModelWithExcludedManyToMany,
     ModelWithFkToModelWithHistoryUsingBaseModelDb,
@@ -2711,6 +2712,27 @@ def test_unique_field_index(self):
         self.assertTrue(self.history_model._meta.get_field("name_keeps_index").db_index)
 
 
+class ModelWithAllNoDBIndexTest(TestCase):
+    def setUp(self):
+        self.model = ModelWithAllNoDBIndex
+        self.history_model = self.model.history.model
+
+    def test_field_indices(self):
+        """
+        All the indexed fields in the original model should be
+        non-indexed in the history model.
+        """
+        for field in ["name", "fk"]:
+            # dropped index
+            self.assertTrue(self.model._meta.get_field(field).db_index)
+            self.assertFalse(self.history_model._meta.get_field(field).db_index)
+
+        # no index
+        no_index = "name_no_index"
+        self.assertFalse(self.model._meta.get_field(no_index).db_index)
+        self.assertFalse(self.history_model._meta.get_field(no_index).db_index)
+
+
 class HistoricForeignKeyTest(TestCase):
     """
     Tests chasing foreign keys across time points naturally with