2 files changed, 20 insertions, 0 deletions
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index d8c0f64d9a..9bf74bbf59 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -170,6 +170,22 @@ class PostgresEngine(
         """Do we support the `RETURNING` clause in insert/update/delete?"""
         return True
 
+    @property
+    def tsquery_func(self) -> str:
+        """
+        Selects a tsquery_* func to use.
+
+        Ref: https://www.postgresql.org/docs/current/textsearch-controls.html
+
+        Returns:
+            The function name.
+        """
+        # Postgres 11 added support for websearch_to_tsquery.
+        assert self._version is not None
+        if self._version >= 110000:
+            return "websearch_to_tsquery"
+        return "plainto_tsquery"
+
     def is_deadlock(self, error: Exception) -> bool:
         if isinstance(error, psycopg2.DatabaseError):
             # https://www.postgresql.org/docs/current/static/errcodes-appendix.html
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: