Make removed fields nullable and non-indexed

reversion/migrations/0001_squashed_0004_auto_20160611_1202.py

@@ -1,9 +1,20 @@
-from django.db import migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
     dependencies = [
         ("reversion", "0002_add_index_on_version_for_content_type_and_db"),
     ]
 
-    operations = []
+    operations = [
+        migrations.AlterField(
+            model_name="revision",
+            name="manager_slug",
+            field=models.CharField(default="default", max_length=191, null=True),
+        ),
+        migrations.AlterField(
+            model_name="version",
+            name="object_id_int",
+            field=models.IntegerField(blank=True, null=True),
+        ),
+    ]

reversion/models.py

@@ -49,7 +49,8 @@ class Revision(models.Model):
 
     manager_slug = models.CharField(
         max_length=191,
-        db_index=True,
+        db_index=False,
+        null=True,
         default="default",
     )
 
@@ -232,8 +233,7 @@ class Version(models.Model):
     object_id_int = models.IntegerField(
         blank=True,
         null=True,
-        db_index=True,
-        help_text="An indexed, integer version of the stored model's primary key, used for faster lookups.",
+        db_index=False,
     )
 
     content_type = models.ForeignKey(