From eb105a90d9504b77544584a9bfc421f9db0a0b13 Mon Sep 17 00:00:00 2001
From: Brett Hoerner <brett@bretthoerner.com>
Date: Wed, 11 Oct 2023 15:36:13 -0600
Subject: [PATCH] feat(plugin-server): reduce constraints related to person
 overrides

---
 latest_migrations.manifest                    |  2 +-
 .../0354_adjust_personoverride_constraints.py | 66 +++++++++++++++++++
 posthog/models/person/person.py               |  6 +-
 3 files changed, 69 insertions(+), 5 deletions(-)
 create mode 100644 posthog/migrations/0354_adjust_personoverride_constraints.py

diff --git a/latest_migrations.manifest b/latest_migrations.manifest
index adaab5c454cc13..58ff194fab23d8 100644
--- a/latest_migrations.manifest
+++ b/latest_migrations.manifest
@@ -5,7 +5,7 @@ contenttypes: 0002_remove_content_type_name
 ee: 0015_add_verified_properties
 otp_static: 0002_throttling
 otp_totp: 0002_auto_20190420_0723
-posthog: 0353_add_5_minute_interval_to_batch_exports
+posthog: 0354_auto_20231011_2132
 sessions: 0001_initial
 social_django: 0010_uid_db_index
 two_factor: 0007_auto_20201201_1019
diff --git a/posthog/migrations/0354_adjust_personoverride_constraints.py b/posthog/migrations/0354_adjust_personoverride_constraints.py
new file mode 100644
index 00000000000000..ec2487b2c007ba
--- /dev/null
+++ b/posthog/migrations/0354_adjust_personoverride_constraints.py
@@ -0,0 +1,66 @@
+# Generated by Django 3.2.19 on 2023-10-11 21:32
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+TRUNCATE_PERSONOVERRIDE_SQL = "TRUNCATE posthog_personoverride, posthog_personoverridemapping"
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("posthog", "0353_add_5_minute_interval_to_batch_exports"),
+    ]
+
+    operations = [
+        migrations.RunSQL(TRUNCATE_PERSONOVERRIDE_SQL, "SELECT 1"),
+        migrations.RemoveConstraint(
+            model_name="personoverride",
+            name="unique override per old_person_id",
+        ),
+        migrations.RemoveField(
+            model_name="personoverride",
+            name="team",
+        ),
+        migrations.RemoveField(
+            model_name="personoverridemapping",
+            name="team_id",
+        ),
+        migrations.AddField(
+            model_name="personoverridemapping",
+            name="team",
+            field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to="posthog.team"),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name="personoverride",
+            name="old_person_id",
+            field=models.OneToOneField(
+                db_column="old_person_id",
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="person_override_old",
+                to="posthog.personoverridemapping",
+            ),
+        ),
+        # drop the old exclusion constraint
+        migrations.RunSQL(
+            "ALTER TABLE posthog_personoverride DROP CONSTRAINT exclude_override_person_id_from_being_old_person_id",
+            """
+            ALTER TABLE posthog_personoverride
+            ADD CONSTRAINT exclude_override_person_id_from_being_old_person_id
+            EXCLUDE USING gist((array[old_person_id, override_person_id]) WITH &&, override_person_id WITH <>)
+            DEFERRABLE
+            INITIALLY DEFERRED
+            """,
+        ),
+        # add the new exclusion constraint
+        migrations.RunSQL(
+            """
+            ALTER TABLE posthog_personoverride
+            ADD CONSTRAINT exclude_override_person_id_from_being_old_person_id
+            EXCLUDE USING gist (old_person_id WITH =, override_person_id WITH =)
+            DEFERRABLE
+            INITIALLY DEFERRED
+            """,
+            "ALTER TABLE posthog_personoverride DROP CONSTRAINT exclude_override_person_id_from_being_old_person_id",
+        ),
+    ]
diff --git a/posthog/models/person/person.py b/posthog/models/person/person.py
index b2b3bb3e367256..d4bb279eb5a9bd 100644
--- a/posthog/models/person/person.py
+++ b/posthog/models/person/person.py
@@ -119,7 +119,7 @@ class Meta:
         ]
 
     id = models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")
-    team_id = models.BigIntegerField()
+    team: models.ForeignKey = models.ForeignKey("Team", on_delete=models.CASCADE)
     uuid = models.UUIDField()
 
 
@@ -138,7 +138,6 @@ class PersonOverride(models.Model):
 
     class Meta:
         constraints = [
-            models.UniqueConstraint(fields=["team", "old_person_id"], name="unique override per old_person_id"),
             models.CheckConstraint(
                 check=~Q(old_person_id__exact=F("override_person_id")),
                 name="old_person_id_different_from_override_person_id",
@@ -146,9 +145,8 @@ class Meta:
         ]
 
     id = models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")
-    team: models.ForeignKey = models.ForeignKey("Team", on_delete=models.CASCADE)
 
-    old_person_id: models.ForeignKey = models.ForeignKey(
+    old_person_id: models.OneToOneField = models.OneToOneField(
         "PersonOverrideMapping",
         db_column="old_person_id",
         related_name="person_override_old",