From 195b6a298d509518bf16d5a421d706ecb2ccdce6 Mon Sep 17 00:00:00 2001
From: Eric Eastwood <erice@element.io>
Date: Wed, 7 Jun 2023 11:45:16 -0500
Subject: [PATCH] Remove redundant `room_memberships` join to find
 participating servers in a room (#15732)

Spawning from https://github.com/matrix-org/synapse/pull/15731
---
 changelog.d/15732.doc                  | 1 +
 docs/usage/administration/admin_faq.md | 5 ++---
 2 files changed, 3 insertions(+), 3 deletions(-)
 create mode 100644 changelog.d/15732.doc

diff --git a/changelog.d/15732.doc b/changelog.d/15732.doc
new file mode 100644
index 0000000000..b0e8639df7
--- /dev/null
+++ b/changelog.d/15732.doc
@@ -0,0 +1 @@
+Simplify query to find participating servers in a room.
diff --git a/docs/usage/administration/admin_faq.md b/docs/usage/administration/admin_faq.md
index 28c3dd53a5..5c9ee7d0aa 100644
--- a/docs/usage/administration/admin_faq.md
+++ b/docs/usage/administration/admin_faq.md
@@ -27,9 +27,8 @@ What servers are currently participating in this room?
 Run this sql query on your db:
 ```sql
 SELECT DISTINCT split_part(state_key, ':', 2)
-    FROM current_state_events AS c
-    INNER JOIN room_memberships AS m USING (room_id, event_id)
-    WHERE room_id = '!cURbafjkfsMDVwdRDQ:matrix.org' AND membership = 'join';
+FROM current_state_events
+WHERE room_id = '!cURbafjkfsMDVwdRDQ:matrix.org' AND membership = 'join';
 ```
 
 What users are registered on my server?