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

* Closes #18191: Remove redundant SQL indexes

* Update developer documentation

* Add a system check for duplicate indexes

netbox/dcim/migrations/0207_remove_redundant_indexes.py

@@ -0,0 +1,17 @@
+# Generated by Django 5.2b1 on 2025-04-03 18:32
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dcim', '0206_load_module_type_profiles'),
+    ]
+
+    operations = [
+        migrations.RemoveIndex(
+            model_name='cabletermination',
+            name='dcim_cablet_termina_884752_idx',
+        ),
+    ]

netbox/dcim/models/cables.py

@@ -299,9 +299,6 @@ class CableTermination(ChangeLoggedModel):
 
     class Meta:
         ordering = ('cable', 'cable_end', 'pk')
-        indexes = (
-            models.Index(fields=('termination_type', 'termination_id')),
-        )
         constraints = (
             models.UniqueConstraint(
                 fields=('termination_type', 'termination_id'),