This table was no longer used, except for a background process
which purged old entries in it.

This reverts commit cabd577460.

There are additional usages of these tables
which need to be removed first.

Drop the event_txn_id table and the tables related to MSC2716,
which is no longer supported in Synapse.

For now this maintains compatible with old Synapses by falling back
to using transaction semantics on a per-access token. A future version
of Synapse will drop support for this.

* Revert "Stop writing to column `user_id` of tables `profiles` and `user_filters` (#15787)"

This reverts commit f25b0f8808.

* newsfragement

Updates the database schema to require a thread_id (by adding a
constraint that the column is non-null) for event_push_actions,
event_push_actions_staging, and event_push_actions_summary.

For PostgreSQL we add the constraint as NOT VALID, then
VALIDATE the constraint a background job to avoid locking
the table during an upgrade.

Each table is updated as a separate schema delta to avoid
deadlocks between them.

For SQLite we simply rebuild the table & copy the data.

This reverts commit a7b3e9ce65.

Updates the database schema to require a thread_id (by adding a
constraint that the column is non-null) for event_push_actions,
event_push_actions_staging, and event_push_actions_summary.

For PostgreSQL we add the constraint as NOT VALID, then
VALIDATE the constraint a background job to avoid locking
the table during an upgrade.

For SQLite we simply rebuild the table & copy the data.

This reverts commit 2a234b788e.

See #15359 for context.

Clean-up from adding the thread_id column, which was initially
null but backfilled with values. It is desirable to require it to now
be non-null.

In addition to altering this column to be non-null, we clean up
obsolete background jobs, indexes, and just-in-time updating
code.

This reverts commit e6af49fbea.

* Add `event_stream_ordering` column to membership state tables

Specifically this adds the column to `current_state_events`,
`local_current_membership` and `room_memberships`. Each of these tables
is regularly joined with the `events` table to get the stream ordering
and denormalising this into each table will yield significant query
performance improvements once used.

* Make denormalised `event_stream_ordering` columns foreign keys
* Add comment in schema file explaining new denormalised columns
* Add triggers to enforce consistency of `event_stream_ordering` columns
* Re-order purge room tables to account for foreign keys
* Bump schema version to 75

Co-authored-by: David Robertson <david.m.robertson1@gmail.com>
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

* Bump schema version

This should have been included in
f10caa73ee (and #14979).

* Changelog

When retrieving counts of notifications segment the results based on the
thread ID, but choose whether to return them as individual threads or as
a single summed field by letting the client opt-in via a sync flag.

The summarization code is also updated to be per thread, instead of per
room.

On matrix.org we have ~5 million stale rows in `event_push_actions_staging`, let's add a background job to make sure we clear them out.

`event_failed_pull_attempts` added in https://github.com/matrix-org/synapse/pull/13589

MSC2716 related tables added in:

 - https://github.com/matrix-org/synapse/pull/10245/files#diff-3d42dfb44d02f7de3aada105e0bdc1cc9dd7f953cbf0f36c5d0f50827bf0320aR1
    - Renamed in https://github.com/matrix-org/synapse/pull/10838/files#diff-2730bfbe9e688b55e46f9371aefe67dac2bd2b2b7d9d6b92774eea1fcfae156dR1
 - https://github.com/matrix-org/synapse/pull/10498/files#diff-c52bbfbb5921a3f6f023b24343668479d966fac164f13b7c39d2197ce3afa7a5R1

We can follow-up this PR with:

 1. Only try to backfill from an event if we haven't tried recently -> https://github.com/matrix-org/synapse/issues/13622
 1. When we decide to backfill that event again, process it in the background so it doesn't block and make `/messages` slow when we know it will probably fail again -> https://github.com/matrix-org/synapse/issues/13623
 1. Generally track failures everywhere we try and fail to pull an event over federation -> https://github.com/matrix-org/synapse/issues/13700

Fix https://github.com/matrix-org/synapse/issues/13621

Part of https://github.com/matrix-org/synapse/issues/13356

Mentioned in [internal doc](https://docs.google.com/document/d/1lvUoVfYUiy6UaHB6Rb4HicjaJAU40-APue9Q4vzuW3c/edit#bookmark=id.qv7cj51sv9i5)

Adds a `thread_id` column to the `event_push_actions`, `event_push_actions_staging`,
and `event_push_summary` tables. This will notifications to be segmented by the thread
in a future pull request. The `thread_id` column stores the root event ID or the special
value `"main"`.

The `thread_id` column for `event_push_actions` and `event_push_summary` is
backfilled with `"main"` for all existing rows. New entries into `event_push_actions`
and `event_push_actions_staging` will get the proper thread ID.

`receipts_linearized` and `receipts_graph` also gain a `thread_id` column, which is similar,
except `NULL` is a special value meaning the receipt is "unthreaded".

See MSC3771 and MSC3773 for where this data will be useful.

Signed-off-by: Mathieu Velten <mathieuv@matrix.org>
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

These tables have been unused since Synapse v1.61.0, although schema version 72
was added in Synapse v1.62.0.

* 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.

* Remove an unused stream ID generator.
* Remove the now unused remote profile cache.

event_edges.room_id is implied by the event id, so there is no need to join on the room id.

This column is unused as of #12209, so let's stop writing to it.

This table is never read, since #11794. We stop writing to it; in future we can
drop it altogether.

This is a first step in dealing with #7721.

The idea is basically that rather than calculating the full set of users a device list update needs to be sent to up front, we instead simply record the rooms the user was in at the time of the change. This will allow a few things:

1. we can defer calculating the set of remote servers that need to be poked about the change; and
2. during `/sync` and `/keys/changes` we can avoid also avoid calculating users who share rooms with other users, and instead just look at the rooms that have changed.

However, care needs to be taken to correctly handle server downgrades. As such this PR writes to both `device_lists_changes_in_room` and the `device_lists_outbound_pokes` table synchronously. In a future release we can then bump the database schema compat version to `69` and then we can assume that the new `device_lists_changes_in_room` exists and is handled.

There is a temporary option to disable writing to `device_lists_outbound_pokes` synchronously, allowing us to test the new code path does work (and by implication upgrading to a future release and downgrading to this one will work correctly).

Note: Ideally we'd do the calculation of room to servers on a worker (e.g. the background worker), but currently only master can write to the `device_list_outbound_pokes` table.

Switching to a sequence means there's no need to track `last_txn` on the
AS state table to generate new TXN IDs. This also means that there is
no longer contention between the AS scheduler and AS handler on updates
to the `application_services_state` table, which will prevent serialization
errors during the complete AS txn transaction.

... and start populating them for new events

This is a follow-up to #10565.

Preparation for dropping this table altogether. Part of #6574.

This reverts commit 158d73ebdd.

this field is never read, so we may as well stop populating it.

Revert "Sort internal changes in changelog"
Revert "Update CHANGES.md"
Revert "1.49.0rc1"
Revert "Revert "Move `glob_to_regex` and `re_word_boundary` to `matrix-python-common` (#11505) (#11527)"
Revert "Refactors in `_generate_sync_entry_for_rooms` (#11515)"
Revert "Correctly register shutdown handler for presence workers (#11518)"
Revert "Fix `ModuleApi.looping_background_call` for non-async functions (#11524)"
Revert "Fix 'delete room' admin api to work on incomplete rooms (#11523)"
Revert "Correctly ignore invites from ignored users (#11511)"
Revert "Fix the test breakage introduced by #11435 as a result of concurrent PRs (#11522)"
Revert "Stabilise support for MSC2918 refresh tokens as they have now been merged into the Matrix specification. (#11435)"
Revert "Save the OIDC session ID (sid) with the device on login (#11482)"
Revert "Add admin API to get some information about federation status (#11407)"
Revert "Include bundled aggregations in /sync and related fixes (#11478)"
Revert "Move `glob_to_regex` and `re_word_boundary` to `matrix-python-common` (#11505)"
Revert "Update backward extremity docs to make it clear that it does not indicate whether we have fetched an events' `prev_events` (#11469)"
Revert "Support configuring the lifetime of non-refreshable access tokens separately to refreshable access tokens. (#11445)"
Revert "Add type hints to `synapse/tests/rest/admin` (#11501)"
Revert "Revert accidental commits to develop."
Revert "Newsfile"
Revert "Give `tests.server.setup_test_homeserver` (nominally!) the same behaviour"
Revert "Move `tests.utils.setup_test_homeserver` to `tests.server`"
Revert "Convert one of the `setup_test_homeserver`s to `make_test_homeserver_synchronous`"
Revert "Disambiguate queries on `state_key` (#11497)"
Revert "Comments on the /sync tentacles (#11494)"
Revert "Clean up tests.storage.test_appservice (#11492)"
Revert "Clean up `tests.storage.test_main` to remove use of legacy code. (#11493)"
Revert "Clean up `tests.test_visibility` to remove legacy code. (#11495)"
Revert "Minor cleanup on recently ported doc pages  (#11466)"
Revert "Add most of the missing type hints to `synapse.federation`. (#11483)"
Revert "Avoid waiting for zombie processes in `synctl stop` (#11490)"
Revert "Fix media repository failing when media store path contains symlinks (#11446)"
Revert "Add type annotations to `tests.storage.test_appservice`. (#11488)"
Revert "`scripts-dev/sign_json`: support for signing events (#11486)"
Revert "Add MSC3030 experimental client and federation API endpoints to get the closest event to a given timestamp (#9445)"
Revert "Port wiki pages to documentation website (#11402)"
Revert "Add a license header and comment. (#11479)"
Revert "Clean-up get_version_string (#11468)"
Revert "Link background update controller docs to summary (#11475)"
Revert "Additional type hints for config module. (#11465)"
Revert "Register the login redirect endpoint for v3. (#11451)"
Revert "Update openid.md"
Revert "Remove mention of OIDC certification from Dex (#11470)"
Revert "Add a note about huge pages to our Postgres doc (#11467)"
Revert "Don't start Synapse master process if `worker_app` is set (#11416)"
Revert "Expose worker & homeserver as entrypoints in `setup.py` (#11449)"
Revert "Bundle relations of relations into the `/relations` result. (#11284)"
Revert "Fix `LruCache` corruption bug with a `size_callback` that can return 0 (#11454)"
Revert "Eliminate a few `Any`s in `LruCache` type hints (#11453)"
Revert "Remove unnecessary `json.dumps` from `tests.rest.admin` (#11461)"
Revert "Merge branch 'master' into develop"

This reverts commit 26b5d2320f.
This reverts commit bce4220f38.
This reverts commit 966b5d0fa0.
This reverts commit 088d748f2c.
This reverts commit 14d593f72d.
This reverts commit 2a3ec6facf.
This reverts commit eccc49d755.
This reverts commit b1ecd19c5d.
This reverts commit 9c55dedc8c.
This reverts commit 2d42e586a8.
This reverts commit 2f053f3f82.
This reverts commit a15a893df8.
This reverts commit 8b4b153c9e.
This reverts commit 494ebd7347.
This reverts commit a77c369897.
This reverts commit 4eb77965cd.
This reverts commit 637df95de6.
This reverts commit e5f426cd54.
This reverts commit 8cd68b8102.
This reverts commit 6cae125e20.
This reverts commit 7be88fbf48.
This reverts commit b3fd99b74a.
This reverts commit f7ec6e7d9e.
This reverts commit 5640992d17.
This reverts commit d26808dd85.
This reverts commit f91624a595.
This reverts commit 16d39a5490.
This reverts commit 8a4c296987.
This reverts commit 49e1356ee3.
This reverts commit d2279f471b.
This reverts commit b50e39df57.
This reverts commit 858d80bf0f.
This reverts commit 435f044807.
This reverts commit f61462e1be.
This reverts commit a6f1a3abec.
This reverts commit 84dc50e160.
This reverts commit ed635d3285.
This reverts commit 7b62791e00.
This reverts commit 153194c771.
This reverts commit f44d729d4c.
This reverts commit a265fbd397.
This reverts commit b9fef1a7cd.
This reverts commit b0eb64ff7b.
This reverts commit f1795463bf.
This reverts commit 70cbb1a5e3.
This reverts commit 42bf020463.
This reverts commit 379f2650cf.
This reverts commit 7ff22d6da4.
This reverts commit 5a0b652d36.
This reverts commit 432a174bc1.
This reverts commit b14f8a1baf6f500997ae4c1d6a6d72094ce14270, reversing
changes made to e713855dca.

We're going to add a `state_key` column to the `events` table, so we need to
add some disambiguation to queries which use it.

* remove unused tables room_stats_historical and user_stats_historical

* update changelog number

* Bump schema compat version comment

* make linter happy

* Update comment to give more info

Co-authored-by: reivilibre <oliverw@matrix.org>

Co-authored-by: reivilibre <oliverw@matrix.org>

Resolve and share `state_groups` for all historical events in batch.  This also helps for showing the appropriate avatar/displayname in Element and will work whenever `/messages` has one of the historical messages as the first message in the batch.

This does have the flaw where if you just insert a single historical event somewhere, it probably won't resolve the state correctly from `/messages` or `/context` since it will grab a non historical event above or below with resolved state which never included the historical state back then. For the same reasions, this also does not work in Element between the transition from actual messages to historical messages. In the Gitter case, this isn't really a problem since all of the historical messages are in one big lump at the beginning of the room.

For a future iteration, might be good to look at `/messages` and `/context` to additionally add the `state` for any historical messages in that batch.

---

How are the `state_groups` shared? To illustrate the `state_group` sharing, see this example:


**Before** (new `state_group` for every event 😬, very inefficient):
```
# Tests from https://github.com/matrix-org/complement/pull/206
$ COMPLEMENT_ALWAYS_PRINT_SERVER_LOGS=1 COMPLEMENT_DIR=../complement ./scripts-dev/complement.sh TestBackfillingHistory/parallel/should_resolve_member_state_events_for_historical_events
create_new_client_event m.room.member event=$_JXfwUDIWS6xKGG4SmZXjSFrizhARM7QblhATVWWUcA state_group=None
create_new_client_event org.matrix.msc2716.insertion event=$1ZBfmBKEjg94d-vGYymKrVYeghwBOuGJ3wubU1-I9y0 state_group=9
create_new_client_event org.matrix.msc2716.insertion event=$Mq2JvRetTyclPuozRI682SAjYp3GqRuPc8_cH5-ezPY state_group=10
create_new_client_event m.room.message event=$MfmY4rBQkxrIp8jVwVMTJ4PKnxSigpG9E2cn7S0AtTo state_group=11
create_new_client_event m.room.message event=$uYOv6V8wiF7xHwOMt-60d1AoOIbqLgrDLz6ZIQDdWUI state_group=12
create_new_client_event m.room.message event=$PAbkJRMxb0bX4A6av463faiAhxkE3FEObM1xB4D0UG4 state_group=13
create_new_client_event org.matrix.msc2716.batch event=$Oy_S7AWN7rJQe_MYwGPEy6RtbYklrI-tAhmfiLrCaKI state_group=14
```

**After** (all events in batch sharing `state_group=10`) (the base insertion event has `state_group=8` which matches the `prev_event` we're inserting next to):

```
# Tests from https://github.com/matrix-org/complement/pull/206
$ COMPLEMENT_ALWAYS_PRINT_SERVER_LOGS=1 COMPLEMENT_DIR=../complement ./scripts-dev/complement.sh TestBackfillingHistory/parallel/should_resolve_member_state_events_for_historical_events
create_new_client_event m.room.member event=$PWomJ8PwENYEYuVNoG30gqtybuQQSZ55eldBUSs0i0U state_group=None
create_new_client_event org.matrix.msc2716.insertion event=$e_mCU7Eah9ABF6nQU7lu4E1RxIWccNF05AKaTT5m3lw state_group=9
create_new_client_event org.matrix.msc2716.insertion event=$ui7A3_GdXIcJq0C8GpyrF8X7B3DTjMd_WGCjogax7xU state_group=10
create_new_client_event m.room.message event=$EnTIM5rEGVezQJiYl62uFBl6kJ7B-sMxWqe2D_4FX1I state_group=10
create_new_client_event m.room.message event=$LGx5jGONnBPuNhAuZqHeEoXChd9ryVkuTZatGisOPjk state_group=10
create_new_client_event m.room.message event=$wW0zwoN50lbLu1KoKbybVMxLbKUj7GV_olozIc5i3M0 state_group=10
create_new_client_event org.matrix.msc2716.batch event=$5ZB6dtzqFBCEuMRgpkU201Qhx3WtXZGTz_YgldL6JrQ state_group=10
```

Before Synapse 1.31 (#9411), we relied on `outlier` being stored in the
`internal_metadata` column. We can now assume nobody will roll back their
deployment that far and drop the legacy support.

As pointed out by @richvdh, https://github.com/matrix-org/synapse/pull/10838#discussion_r715424244

Retroactively summarize `61` - `64`