fix(aci): add index on group in DetectorGroup before group unique operation (#103113)

Author: cathteng

src/sentry/workflow_engine/migrations/0095_unique_detectorgroup_group.py

@@ -1,9 +1,7 @@
-# Generated by Django 5.2.1 on 2025-11-06 22:43
+# Generated by Django 5.2.1 on 2025-11-10 23:25
 
-import django.db.models.deletion
 from django.db import migrations
 
-import sentry.db.models.fields.foreignkey
 from sentry.new_migrations.migrations import CheckedMigration
 
 
@@ -28,15 +26,12 @@ class Migration(CheckedMigration):
     ]
 
     operations = [
-        migrations.AlterField(
-            model_name="detectorgroup",
-            name="group",
-            field=sentry.db.models.fields.foreignkey.FlexibleForeignKey(
-                on_delete=django.db.models.deletion.CASCADE, to="sentry.group", unique=True
-            ),
+        migrations.AlterUniqueTogether(
+            name="detectorgroup",
+            unique_together={("detector", "group"), ("group",)},
         ),
         migrations.AlterUniqueTogether(
             name="detectorgroup",
-            unique_together=set(),
+            unique_together={("group",)},
         ),
     ]

src/sentry/workflow_engine/models/detector_group.py

@@ -13,11 +13,12 @@ class DetectorGroup(DefaultFieldsModel):
     __relocation_scope__ = RelocationScope.Excluded
 
     detector = FlexibleForeignKey("workflow_engine.Detector", on_delete=models.CASCADE)
-    group = FlexibleForeignKey("sentry.Group", on_delete=models.CASCADE, unique=True)
+    group = FlexibleForeignKey("sentry.Group", on_delete=models.CASCADE)
 
     class Meta:
         db_table = "workflow_engine_detectorgroup"
         app_label = "workflow_engine"
         indexes = [
             models.Index(fields=["detector", "-date_added"], name="detectorgroup_det_date_idx"),
         ]
+        unique_together = ("group",)