Fix the inbound PDU metric (#10279)

This broke in #10272

3 files changed, 16 insertions, 0 deletions

diff --git a/synapse/storage/engines/_base.py b/synapse/storage/engines/_base.py
index 1882bfd9cf..20cd63c330 100644
--- a/synapse/storage/engines/_base.py
+++ b/synapse/storage/engines/_base.py
@@ -49,6 +49,12 @@ class BaseDatabaseEngine(Generic[ConnectionType], metaclass=abc.ABCMeta):
         """
         ...
 
+    @property
+    @abc.abstractmethod
+    def supports_returning(self) -> bool:
+        """Do we support the `RETURNING` clause in insert/update/delete?"""
+        ...
+
     @abc.abstractmethod
     def check_database(
         self, db_conn: ConnectionType, allow_outdated_version: bool = False
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index 21411c5fea..30f948a0f7 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -133,6 +133,11 @@ class PostgresEngine(BaseDatabaseEngine):
         """Do we support using `a = ANY(?)` and passing a list"""
         return True
 
+    @property
+    def supports_returning(self) -> bool:
+        """Do we support the `RETURNING` clause in insert/update/delete?"""
+        return True
+
     def is_deadlock(self, error):
         if isinstance(error, self.module.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 5fe1b205e1..70d17d4f2c 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -60,6 +60,11 @@ class Sqlite3Engine(BaseDatabaseEngine["sqlite3.Connection"]):
         """Do we support using `a = ANY(?)` and passing a list"""
         return False
 
+    @property
+    def supports_returning(self) -> bool:
+        """Do we support the `RETURNING` clause in insert/update/delete?"""
+        return self.module.sqlite_version_info >= (3, 35, 0)
+
     def check_database(self, db_conn, allow_outdated_version: bool = False):
         if not allow_outdated_version:
             version = self.module.sqlite_version_info