Enforce that we use index scans (rather than seq scans), which we also do for state queries. The reason to enforce this is that we can't correctly get PostgreSQL to understand the distribution of `stream_ordering` depends on `highlight`, and so it always defaults (on matrix.org) to sequential scans.
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.
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.
if a Synapse deployment upgraded (from < 1.62.0 to >= 1.70.0) then it
is possible for schema deltas to run before background updates causing
drift in the database schema due to:
1. A delta registered a background update to create an index.
2. A delta dropped the above index if it exists (but it yet exist won't since
the background job hasn't run).
3. The code assumed the index was dropped.
To fix this we:
1. Cancel the background update which could create the index.
2. Drop the index again.
3. Drop a related index which is dropped by the background update.
Applies the proper logic for unthreaded and threaded receipts to either
apply to all events in the room or only events in the same thread, respectively.
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.
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.
Partial indices have been supported since SQLite 3.8, but Synapse
now requires >= 3.27, so we can enable support for them.
This requires rebuilding previous indices which were partial on
PostgreSQL, but not on SQLite.
This improves load times for push rules:
| Version | Time per user | Time for 1k users |
| -------------------- | ------------- | ----------------- |
| Before | 138 µs | 138ms |
| Now (with custom) | 2.11 µs | 2.11ms |
| Now (without custom) | 49.7 ns | 0.05 ms |
This therefore has a large impact on send times for rooms
with large numbers of local users in the room.
* Clarifies comments.
* Fixes an erroneous comment (about return type) added in #13455
(ec24813220).
* Clarifies the name of a variable.
* Simplifies logic of pulling out the latest join for the requesting user.
This adds support for the stable identifiers of MSC2285 while
continuing to support the unstable identifiers behind the configuration
flag. These will be removed in a future version.
* Adds docstrings and inline comments.
* Formats SQL queries using triple quoted strings.
* Minor formatting changes.
* Avoid fetching `event_push_summary_stream_ordering` multiple times
in the same transactions.
This happened if we encountered a stream ordering in `event_push_actions` that had more rows than the batch size of the delete, as If we don't delete any rows in an iteration then the next time round we get the exact same stream ordering and get stuck.
==============================
Bugfixes
--------
- Update the version of the [ldap3 plugin](https://github.com/matrix-org/matrix-synapse-ldap3/) included in the `matrixdotorg/synapse` DockerHub images and the Debian packages hosted on `packages.matrix.org` to 0.2.1. This fixes [a bug](https://github.com/matrix-org/matrix-synapse-ldap3/pull/163) with usernames containing uppercase characters. ([\#13156](https://github.com/matrix-org/synapse/issues/13156))
- Fix a bug introduced in Synapse 1.62.0rc1 affecting unread counts for users on small servers. ([\#13168](https://github.com/matrix-org/synapse/issues/13168))
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Merge tag 'v1.62.0rc3' into develop
Synapse 1.62.0rc3 (2022-07-04)
==============================
Bugfixes
--------
- Update the version of the [ldap3 plugin](https://github.com/matrix-org/matrix-synapse-ldap3/) included in the `matrixdotorg/synapse` DockerHub images and the Debian packages hosted on `packages.matrix.org` to 0.2.1. This fixes [a bug](https://github.com/matrix-org/matrix-synapse-ldap3/pull/163) with usernames containing uppercase characters. ([\#13156](https://github.com/matrix-org/synapse/issues/13156))
- Fix a bug introduced in Synapse 1.62.0rc1 affecting unread counts for users on small servers. ([\#13168](https://github.com/matrix-org/synapse/issues/13168))
Fixes#11887 hopefully.
The core change here is that `event_push_summary` now holds a summary of counts up until a much more recent point, meaning that the range of rows we need to count in `event_push_actions` is much smaller.
This needs two major changes:
1. When we get a receipt we need to recalculate `event_push_summary` rather than just delete it
2. The logic for deleting `event_push_actions` is now divorced from calculating `event_push_summary`.
In future it would be good to calculate `event_push_summary` while we persist a new event (it should just be a case of adding one to the relevant rows in `event_push_summary`), as that will further simplify the get counts logic and remove the need for us to periodically update `event_push_summary` in a background job.