User Cursor.__iter__ instead of fetchall

This prevents unnecessary construction of lists

1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/storage/events.py b/synapse/storage/events.py

index 3c8393bfe8..9f2045e8d8 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -834,7 +834,7 @@ class EventsStore(SQLBaseStore):
 
         have_persisted = {
             event_id: outlier
-            for event_id, outlier in txn.fetchall()
+            for event_id, outlier in txn
         }
 
         to_remove = set()