Closes #18191: Remove duplicate SQL indexes (#19074)

* Closes #18191: Remove redundant SQL indexes

* Update developer documentation

* Add a system check for duplicate indexes

netbox/vpn/migrations/0009_remove_redundant_indexes.py

@@ -0,0 +1,21 @@
+# Generated by Django 5.2b1 on 2025-04-03 18:32
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('vpn', '0008_add_l2vpn_status'),
+    ]
+
+    operations = [
+        migrations.RemoveIndex(
+            model_name='l2vpntermination',
+            name='vpn_l2vpnte_assigne_9c55f8_idx',
+        ),
+        migrations.RemoveIndex(
+            model_name='tunneltermination',
+            name='vpn_tunnelt_termina_c1f04b_idx',
+        ),
+    ]

netbox/vpn/models/l2vpn.py

@@ -110,9 +110,6 @@ class L2VPNTermination(NetBoxModel):
 
     class Meta:
         ordering = ('l2vpn',)
-        indexes = (
-            models.Index(fields=('assigned_object_type', 'assigned_object_id')),
-        )
         constraints = (
             models.UniqueConstraint(
                 fields=('assigned_object_type', 'assigned_object_id'),

netbox/vpn/models/tunnels.py

@@ -138,9 +138,6 @@ class TunnelTermination(CustomFieldsMixin, CustomLinksMixin, TagsMixin, ChangeLo
 
     class Meta:
         ordering = ('tunnel', 'role', 'pk')
-        indexes = (
-            models.Index(fields=('termination_type', 'termination_id')),
-        )
         constraints = (
             models.UniqueConstraint(
                 fields=('termination_type', 'termination_id'),