Don't seqscan event_json due to relates_to_id

1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/storage/databases/main/events_bg_updates.py b/synapse/storage/databases/main/events_bg_updates.py

index f92d824876..ae3a8a63e4 100644
--- a/synapse/storage/databases/main/events_bg_updates.py
+++ b/synapse/storage/databases/main/events_bg_updates.py
@@ -1108,7 +1108,7 @@ class EventsBackgroundUpdatesStore(SQLBaseStore):
                 """
                 SELECT event_id, json FROM event_json
                 LEFT JOIN event_relations USING (event_id)
-                WHERE event_id > ? AND relates_to_id IS NULL
+                WHERE event_id > ? AND event_relations.event_id IS NULL
                 ORDER BY event_id LIMIT ?
                 """,
                 (last_event_id, batch_size),