MatrixSynapse/synapse/storage/schema/main/delta/56/event_labels.sql

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1.2 KiB
SQL

/* Copyright 2019 The Matrix.org Foundation C.I.C.
*
* 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.
*/
-- room_id and topological_ordering are denormalised from the events table in order to
-- make the index work.
CREATE TABLE IF NOT EXISTS event_labels (
event_id TEXT,
label TEXT,
room_id TEXT NOT NULL,
topological_ordering BIGINT NOT NULL,
PRIMARY KEY(event_id, label)
);
-- This index enables an event pagination looking for a particular label to index the
-- event_labels table first, which is much quicker than scanning the events table and then
-- filtering by label, if the label is rarely used relative to the size of the room.
CREATE INDEX event_labels_room_id_label_idx ON event_labels(room_id, label, topological_ordering);