forked-synapse/synapse/storage/schema/__init__.py
Richard van der Hoff 75fb10ee45
Clean up schema for event_edges (#12893)
* Remove redundant references to `event_edges.room_id`

We don't need to care about the room_id here, because we are already checking
the event id.

* Clean up the event_edges table

We make a number of changes to `event_edges`:

 * We give the `room_id` and `is_state` columns defaults (null and false
   respectively) so that we can stop populating them.
 * We drop any rows that have `is_state` set true - they should no longer
   exist.
 * We drop any rows that do not exist in `events` - these should not exist
   either.
 * We drop the old unique constraint on all the colums, which wasn't much use.
 * We create a new unique index on `(event_id, prev_event_id)`.
 * We add a foreign key constraint to `events`.

These happen rather differently depending on whether we are on Postgres or
SQLite. For SQLite, we just rebuild the whole table, copying only the rows we
want to keep. For Postgres, we try to do things in the background as much as
possible.

* Stop populating `event_edges.room_id` and `is_state`

We can just rely on the defaults.
2022-06-15 12:29:42 +01:00

90 lines
3.7 KiB
Python

# Copyright 2021 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.
SCHEMA_VERSION = 72 # remember to update the list below when updating
"""Represents the expectations made by the codebase about the database schema
This should be incremented whenever the codebase changes its requirements on the
shape of the database schema (even if those requirements are backwards-compatible with
older versions of Synapse).
See https://matrix-org.github.io/synapse/develop/development/database_schema.html
for more information on how this works.
Changes in SCHEMA_VERSION = 61:
- The `user_stats_historical` and `room_stats_historical` tables are not written and
are not read (previously, they were written but not read).
- MSC2716: Add `insertion_events` and `insertion_event_edges` tables to keep track
of insertion events in order to navigate historical chunks of messages.
- MSC2716: Add `chunk_events` table to track how the chunk is labeled and
determines which insertion event it points to.
Changes in SCHEMA_VERSION = 62:
- MSC2716: Add `insertion_event_extremities` table that keeps track of which
insertion events need to be backfilled.
Changes in SCHEMA_VERSION = 63:
- The `public_room_list_stream` table is not written nor read to
(previously, it was written and read to, but not for any significant purpose).
https://github.com/matrix-org/synapse/pull/10565
Changes in SCHEMA_VERSION = 64:
- MSC2716: Rename related tables and columns from "chunks" to "batches".
Changes in SCHEMA_VERSION = 65:
- MSC2716: Remove unique event_id constraint from insertion_event_edges
because an insertion event can have multiple edges.
- Remove unused tables `user_stats_historical` and `room_stats_historical`.
Changes in SCHEMA_VERSION = 66:
- Queries on state_key columns are now disambiguated (ie, the codebase can handle
the `events` table having a `state_key` column).
Changes in SCHEMA_VERSION = 67:
- state_events.prev_state is no longer written to.
Changes in SCHEMA_VERSION = 68:
- event_reference_hashes is no longer read.
- `events` has `state_key` and `rejection_reason` columns, which are populated for
new events.
Changes in SCHEMA_VERSION = 69:
- We now write to `device_lists_changes_in_room` table.
- We now use a PostgreSQL sequence to generate future txn_ids for
`application_services_txns`. `application_services_state.last_txn` is no longer
updated.
Changes in SCHEMA_VERSION = 70:
- event_reference_hashes is no longer written to.
Changes in SCHEMA_VERSION = 71:
- event_edges.room_id is no longer read from.
- Tables related to groups are no longer accessed.
Changes in SCHEMA_VERSION = 72:
- event_edges.(room_id, is_state) are no longer written to.
"""
SCHEMA_COMPAT_VERSION = (
# We no longer maintain `event_edges.room_id`, so synapses with SCHEMA_VERSION < 71
# will break.
71
)
"""Limit on how far the synapse codebase can be rolled back without breaking db compat
This value is stored in the database, and checked on startup. If the value in the
database is greater than SCHEMA_VERSION, then Synapse will refuse to start.
"""