2 files changed, 34 insertions, 0 deletions
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index 289b6bc281..b7c4eda338 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -22,6 +22,13 @@ class PostgresEngine(object):
     def __init__(self, database_module, database_config):
         self.module = database_module
         self.module.extensions.register_type(self.module.extensions.UNICODE)
+
+        # Disables passing `bytes` to txn.execute, c.f. #6186. If you do
+        # actually want to use bytes than wrap it in `bytearray`.
+        def _disable_bytes_adapter(_):
+            raise Exception("Passing bytes to DB is disabled.")
+
+        self.module.extensions.register_adapter(bytes, _disable_bytes_adapter)
         self.synchronous_commit = database_config.get("synchronous_commit", True)
         self._version = None  # unknown as yet
 
@@ -72,6 +79,19 @@ class PostgresEngine(object):
         """
         return True
 
+    @property
+    def supports_tuple_comparison(self):
+        """
+        Do we support comparing tuples, i.e. `(a, b) > (c, d)`?
+        """
+        return True
+
+    @property
+    def supports_using_any_list(self):
+        """Do we support using `a = ANY(?)` and passing a list
+        """
+        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 e9b9caa49a..ddad17dc5a 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -38,6 +38,20 @@ class Sqlite3Engine(object):
         """
         return self.module.sqlite_version_info >= (3, 24, 0)
 
+    @property
+    def supports_tuple_comparison(self):
+        """
+        Do we support comparing tuples, i.e. `(a, b) > (c, d)`? This requires
+        SQLite 3.15+.
+        """
+        return self.module.sqlite_version_info >= (3, 15, 0)
+
+    @property
+    def supports_using_any_list(self):
+        """Do we support using `a = ANY(?)` and passing a list
+        """
+        return False
+
     def check_database(self, txn):
         pass