Enable WAL for SQLite (#13897)

Signed-off-by: Lorenzo Manacorda <lorenzo@mailbox.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py

index faa574dbfd..14260442b6 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -88,6 +88,10 @@ class Sqlite3Engine(BaseDatabaseEngine[sqlite3.Connection, sqlite3.Cursor]):
 
         db_conn.create_function("rank", 1, _rank)
         db_conn.execute("PRAGMA foreign_keys = ON;")
+
+        # Enable WAL.
+        # see https://www.sqlite.org/wal.html
+        db_conn.execute("PRAGMA journal_mode = WAL;")
         db_conn.commit()
 
     def is_deadlock(self, error: Exception) -> bool: