Matt Aitken
ef04cc39ef
## Problem
`ClickHouseRunsRepository.listRunIds` / `listRuns` order results by the
composite key `(created_at, run_id)`, but the cursor predicate cut on
`run_id` **alone**:
```ts
.where("run_id < {runId: String}", { runId: cursor })
.orderBy("created_at DESC, run_id DESC")
```
This is only sound when `run_id` lexicographic order matches
`created_at` order. `run_id`s are cuids — only coarsely time-sortable —
so when a burst of runs is created within a sub-second window, the two
orders can diverge. When they do, the next-page predicate (`run_id <
cursor`, where `cursor` is the *last* page element = the smallest
`created_at`, not necessarily the smallest `run_id`):
- **re-includes** rows already returned on a previous page (duplicates),
and
- **skips** rows it should have returned (silent data loss).
For bulk **replay** this caused runs to be replayed more than once
(replay has no idempotency guard). For the dashboard and the `runs.list`
API it could silently repeat or skip runs at page boundaries.
## Fix
Make the cursor predicate match the composite ordering:
- Cursors now encode the full `(created_at, run_id)` key as an **opaque
URL-safe base64 token**
(`base64url({"c":<createdAtMs>,"r":"<runId>"})`), and the query cuts on
the matching tuple — `(created_at, run_id) < (…)` forward / `> (…)`
backward.
- The `ORDER BY` is unchanged, so the query stays aligned with the
table's primary key — no performance regression (the tuple range
predicate is actually more index-friendly than `run_id <` alone).
- Cursors are **server-issued opaque tokens** (the SDK only echoes
`pagination.next` / `pagination.previous` back), so this needs **no
client/SDK update**. Legacy cursors were the bare internal `run_id`;
they're detected by decode failure (a cuid isn't a valid base64-wrapped
JSON payload) and fall back to the old `run_id`-only predicate, so
in-flight cursors keep working and drain naturally. New cursors also no
longer expose a bare internal run id.
- `listRunIds` is now the single cursor-aware list primitive: it returns
`{ runIds, pagination: { nextCursor, previousCursor } }`, and `listRuns`
builds on it (one place constructs cursors). Bulk actions consume the
same method and advance by `pagination.nextCursor`, finishing when it's
`null`.
- `getTaskRunsQueryBuilder` now also selects
`toUnixTimestamp64Milli(created_at) AS created_at_ms`, using a dedicated
`TaskRunListQueryResult` schema. The shared `TaskRunV2QueryResult` stays
`run_id`-only so the run-engine pending-version lookup
(`getPendingVersionIdsQueryBuilder`, which selects only `run_id`)
doesn't fail validation on a column it doesn't query.
## Tests
New `runsRepositoryCursor.test.ts` (testcontainer-backed, real
Postgres→ClickHouse replication):
- **forward** pagination returns every run exactly once when `run_id`
order is the reverse of `created_at` order (reproduces the
duplicate/skip bug — fails on `main`; this
walk-until-`nextCursor`-null-and-assert-complete is exactly the bulk
action's iteration),
- **backward** pagination round-trips to the previous page across a
boundary,
- **legacy** bare-`run_id` cursor still uses the old predicate
(backwards compatibility).
The existing `runsRepository` suites (part1–4) still pass; `part4`'s
`count new runs with listRunIds` test was updated for the new `{ runIds,
pagination }` return shape, and the `clickhouse` `taskRuns`
query-builder snapshots were regenerated for the added `created_at_ms`
column.
## Notes
- Separate, pre-existing issue (out of scope, not introduced here):
`listRuns`' backward display-slicing (`rows.slice(1, size+1)` when
`hasMore`) has an off-by-one that can return a straddled page. Tracked
separately.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ClickHouse Table Naming Conventions
The following document is heavily inspired by the Unkey ClickHouse naming conventions.
This document outlines the naming conventions for tables and materialized views in our ClickHouse setup. Adhering to these conventions ensures consistency, clarity, and ease of management across our data infrastructure.
General Rules
- Use lowercase letters and separate words with underscores.
- Avoid ClickHouse reserved words and special characters in names.
- Be descriptive but concise.
Table Naming Convention
Format: [prefix]_[domain]_[description]_[version]
Prefixes
raw_: Input data tablestmp_{yourname}_: Temporary tables for experiments, add your name, so it's easy to identify ownership.
Versioning
- Version numbers:
_v1,_v2, etc.
Aggregation Suffixes
For aggregated or summary tables, use suffixes like:
_per_day_per_month_summary
Materialized View Naming Convention
Format: [description]_[aggregation]_mv_[version]
- Always suffix with
mv_[version] - Include a description of the view's purpose
- Add aggregation level if applicable
Examples
-
Raw Data Table:
raw_sales_transactions_v1 -
Materialized View:
active_users_per_day_mv_v2 -
Temporary Table:
tmp_eric_user_analysis_v1 -
Aggregated Table:
sales_summary_per_hour_mv_v1
Consistency Across Related Objects
Maintain consistent naming across related tables, views, and other objects:
raw_user_activity_v1user_activity_per_day_v1user_activity_per_day_mv_v1
By following these conventions, we ensure a clear, consistent, and scalable naming structure for our ClickHouse setup.