<!-- CURSOR_AGENT_PR_BODY_BEGIN -->
# Which Problems Are Solved
Handler/v2 projections (`users14` and every other event projection) can
overlook committed events under load:
- `eventstore.commands_to_events` stamped `position` with `NOW()`
(transaction start). A slow create TX could commit after a faster TX
that started later, so the projector stored a later position and never
saw the earlier one.
- Resume used `OFFSET` on a **filtered** row count. That could skip
`in_tx_order = 1` at the next position (for example `user.human.added`).
- Two transactions in the same microsecond both start at `in_tx_order =
1`. A cursor of `in_tx_order > last` alone would drop the other TX’s
first event.
This does not repair rows that are already missing from projections.
# How the Problems Are Solved
- Setup step 77 replaces `eventstore.commands_to_events` so `created_at
= statement_timestamp()` and `position = EXTRACT(EPOCH FROM
clock_timestamp())` at INSERT time. Initialise `08_events_table.sql`
matches that for new databases. The function is `VOLATILE` to match
`clock_timestamp()`.
- The projector still drains in-flight writers with `pg_advisory_lock` /
`pg_advisory_unlock` in one statement, then caps with `position <=
EXTRACT(EPOCH FROM now())` (projector TX start). The exclusive lock is
**not** held across the event `SELECT`. The cap must stay `now()`, not
`clock_timestamp()`, or later inserts become a high-water mark.
- Resume is a lexicographic `EventSortKey` on `(position, in_tx_order,
instance_id, aggregate_type, aggregate_id, sequence)` via
`AfterEventSortKey`. SQL `OFFSET` is no longer used for projection
catch-up.
- Handler and FieldHandler persist the last event’s `in_tx_order` in
`current_states.filter_offset` (existing column, new meaning). Step 77
backfills matching rows from `events2`; unmatched rows keep their
previous value.
# Additional Changes
- `eventstore.Event` exposes `InTxOrder() uint32` (BaseEvent, repository
Event, v3 event, v1 models).
- v3 push SELECT/RETURNING now includes `in_tx_order` so newly written
events carry a real ordinal.
- `WithMinPosition` stays an inclusive `PositionAtLeast` floor and does
not smash the sort-key cursor.
- `SearchQuery.PositionAfter(decimal)` is unchanged (used by
access-token lookup). Do not confuse it with
`SearchQueryBuilder.AfterEventSortKey`.
- `commands_to_events` in setup 77 and initialise 08 is `VOLATILE
PARALLEL SAFE`. Shipped 40/64/70 stay `STABLE` because they still stamp
with `NOW()`.
- Drop unused `last_owner TEXT` DECLARE from setup 77 and initialise
`08_events_table.sql` (`i INTEGER` remains for the enforce-owner loop).
Shipped 40/64/70 keep the leftover.
- This PR’s migration is numbered 77 because `main` already has setup 76
(`76_users14_login_equality_indexes`). First-loop order is s70, then
main’s 76, then this 77.
# Additional Context
**Reviewer map**
| Start here | Why |
| --- | --- |
| `cmd/setup/77.sql` + `cmd/setup/77.go` | Position stamp + atomic
function replace/backfill after shipped `s70` and main’s s76 |
| `internal/eventstore/event_sort_key.go` + `search_query.go` |
Canonical cursor and `AfterEventSortKey` |
| `internal/eventstore/handler/v2/{state.go,handler.go}` |
Persist/resume cursor; `eventQuery` |
| `internal/eventstore/repository/sql/{query.go,postgres.go}` | Tuple
`>` filter, 6-column `ORDER BY`, await cap |
| `internal/eventstore/v3/push.go` / `push.sql` | Scan `in_tx_order` on
write |
Mechanical / low-risk: handler and query test fixtures, Event interface
stubs (`event_base.go`, repository Event, mocks, v1 models).
**Do not look for** a `70.sql` change — shipped migrations stay as on
`main`. Setup 40/64 still use `NOW()`; step 77 overwrites the function
afterward. Fresh `FirstInstance` (runs before `s70`) can still stamp
`NOW()` until 77; runtime pushes after 77 use `clock_timestamp()`.
Main’s `cmd/setup/76.go` is the users14 login-equality indexes, not this
stamp.
**Rollout**
1. Run setup so 77 replaces `commands_to_events` and backfills
`filter_offset`.
2. Restart ZITADEL so projectors load the new resume path.
3. Existing missing `users14` rows are not repaired by this PR.
**Tests**
- `go test ./internal/eventstore/... ./cmd/setup/`
- Sort-key SQL fixtures in `query_sort_key_test.go` (no `OFFSET`;
aggregate-id queries keep 6-column `ORDER BY`)
- `cmd/setup/77_test.go` asserts the embed has no unused `last_owner`
and still uses `clock_timestamp()` / `VOLATILE PARALLEL SAFE`
Related: #8509, #10480 (remove OFFSET), #10560 (advisory locks), #10710
(stable ORDER BY).
Out of scope: repairing already-missing projection rows, holding the
exclusive lock during SELECT, rewriting historical setup 40/64 SQL.
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---------
Co-authored-by: Cursor Agent <[email protected]>
Co-authored-by: Silvan <[email protected]>
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