Fixed removal of new presence stream states

changelog.d/10014.bugfix

@@ -0,0 +1 @@
+Fixed deletion of new presence stream states from database. 

synapse/storage/databases/main/presence.py

@@ -97,6 +97,15 @@ def _update_presence_txn(self, txn, stream_orderings, presence_states):
             )
             txn.call_after(self._get_presence_for_user.invalidate, (state.user_id,))
 
+        # Delete old rows to stop database from getting really big
+        sql = "DELETE FROM presence_stream WHERE stream_id < ? AND "
+
+        for states in batch_iter(presence_states, 50):
+            clause, args = make_in_list_sql_clause(
+                self.database_engine, "user_id", [s.user_id for s in states]
+            )
+            txn.execute(sql + clause, [stream_id] + list(args))
+
         # Actually insert new rows
         self.db_pool.simple_insert_many_txn(
             txn,
@@ -117,15 +126,6 @@ def _update_presence_txn(self, txn, stream_orderings, presence_states):
             ],
         )
 
-        # Delete old rows to stop database from getting really big
-        sql = "DELETE FROM presence_stream WHERE stream_id < ? AND "
-
-        for states in batch_iter(presence_states, 50):
-            clause, args = make_in_list_sql_clause(
-                self.database_engine, "user_id", [s.user_id for s in states]
-            )
-            txn.execute(sql + clause, [stream_id] + list(args))
-
     async def get_all_presence_updates(
         self, instance_name: str, last_id: int, current_id: int, limit: int
     ) -> Tuple[List[Tuple[int, list]], int, bool]: