Store invites in a separate table.

synapse/storage/schema/delta/31/invites.sql

@@ -0,0 +1,28 @@
+/* Copyright 2016 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+CREATE TABLE invites(
+    stream_id BIGINT NOT NULL,
+    inviter TEXT NOT NULL,
+    invitee TEXT NOT NULL,
+    event_id TEXT NOT NULL,
+    room_id TEXT NOT NULL,
+    locally_rejected TEXT,
+    replaced_by TEXT
+);
+
+CREATE INDEX invites_id ON invites(stream_id);
+CREATE INDEX invites_for_user_idx ON invites(invitee, locally_rejected, replaced_by, room_id);