From 4db7862e0fce1a7b1a84458d572ba006b032c737 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <clokep@users.noreply.github.com>
Date: Wed, 13 Jul 2022 09:55:14 -0400
Subject: [PATCH] Drop unused tables from groups/communities. (#12967)

These tables have been unused since Synapse v1.61.0, although schema version 72
was added in Synapse v1.62.0.
---
 changelog.d/12967.removal                     |  1 +
 synapse/_scripts/synapse_port_db.py           | 16 ----------
 synapse/storage/schema/__init__.py            |  7 +++--
 .../schema/main/delta/72/03remove_groups.sql  | 31 +++++++++++++++++++
 4 files changed, 36 insertions(+), 19 deletions(-)
 create mode 100644 changelog.d/12967.removal
 create mode 100644 synapse/storage/schema/main/delta/72/03remove_groups.sql

diff --git a/changelog.d/12967.removal b/changelog.d/12967.removal
new file mode 100644
index 000000000..0aafd6a4d
--- /dev/null
+++ b/changelog.d/12967.removal
@@ -0,0 +1 @@
+Drop tables used for groups/communities.
diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py
index 26834a437..543bba27c 100755
--- a/synapse/_scripts/synapse_port_db.py
+++ b/synapse/_scripts/synapse_port_db.py
@@ -166,22 +166,6 @@ IGNORED_TABLES = {
     "ui_auth_sessions",
     "ui_auth_sessions_credentials",
     "ui_auth_sessions_ips",
-    # Groups/communities is no longer supported.
-    "group_attestations_remote",
-    "group_attestations_renewals",
-    "group_invites",
-    "group_roles",
-    "group_room_categories",
-    "group_rooms",
-    "group_summary_roles",
-    "group_summary_room_categories",
-    "group_summary_rooms",
-    "group_summary_users",
-    "group_users",
-    "groups",
-    "local_group_membership",
-    "local_group_updates",
-    "remote_profile_cache",
 }
 
 
diff --git a/synapse/storage/schema/__init__.py b/synapse/storage/schema/__init__.py
index dc237e303..a9a88c8bf 100644
--- a/synapse/storage/schema/__init__.py
+++ b/synapse/storage/schema/__init__.py
@@ -74,13 +74,14 @@ Changes in SCHEMA_VERSION = 71:
 
 Changes in SCHEMA_VERSION = 72:
     - event_edges.(room_id, is_state) are no longer written to.
+    - Tables related to groups are dropped.
 """
 
 
 SCHEMA_COMPAT_VERSION = (
-    # We no longer maintain `event_edges.room_id`, so synapses with SCHEMA_VERSION < 71
-    # will break.
-    71
+    # The groups tables are no longer accessible, so synapses with SCHEMA_VERSION < 72
+    # could break.
+    72
 )
 """Limit on how far the synapse codebase can be rolled back without breaking db compat
 
diff --git a/synapse/storage/schema/main/delta/72/03remove_groups.sql b/synapse/storage/schema/main/delta/72/03remove_groups.sql
new file mode 100644
index 000000000..b7c5894de
--- /dev/null
+++ b/synapse/storage/schema/main/delta/72/03remove_groups.sql
@@ -0,0 +1,31 @@
+/* Copyright 2022 The Matrix.org Foundation C.I.C
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+-- Remove the tables which powered the unspecced groups/communities feature.
+DROP TABLE IF EXISTS group_attestations_remote;
+DROP TABLE IF EXISTS group_attestations_renewals;
+DROP TABLE IF EXISTS group_invites;
+DROP TABLE IF EXISTS group_roles;
+DROP TABLE IF EXISTS group_room_categories;
+DROP TABLE IF EXISTS group_rooms;
+DROP TABLE IF EXISTS group_summary_roles;
+DROP TABLE IF EXISTS group_summary_room_categories;
+DROP TABLE IF EXISTS group_summary_rooms;
+DROP TABLE IF EXISTS group_summary_users;
+DROP TABLE IF EXISTS group_users;
+DROP TABLE IF EXISTS groups;
+DROP TABLE IF EXISTS local_group_membership;
+DROP TABLE IF EXISTS local_group_updates;
+DROP TABLE IF EXISTS remote_profile_cache;