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2026-07-13 13:32:57 +08:00

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ClickHouse Package

@internal/clickhouse - ClickHouse client for analytics and observability data.

Migrations

Goose-format SQL migrations live in schema/. Two rules below are load-bearing — both can block a deploy.

Rule 1: number to max + 1, never slot in

Goose runs in strict mode in the deploy pipeline. If a migration file numbered below the version currently recorded in goose_db_version ever shows up, goose refuses to apply it and the deploy fails:

goose run: error: found 1 missing migrations before current version 30:
  version 29: 029_add_task_kind_to_task_runs_v2.sql

When adding a migration:

  1. Look at schema/ and take the largest existing number, call it N.
  2. Name your file 0(N+1)_descriptive_name.sql.
  3. If you've been on a branch while main added migrations, rebase and renumber before opening the PR — a file numbered below the new max will block the next deploy after your PR merges.

Rule 2: DDL must be idempotent

Migrations can be applied out of order in some environments (goose up --allow-missing for local recovery, manual fixups, etc.) and may be retried. Always use idempotent forms so a re-apply is a no-op:

-- +goose Up
ALTER TABLE trigger_dev.your_table
  ADD COLUMN IF NOT EXISTS new_column String DEFAULT '';

-- +goose Down
ALTER TABLE trigger_dev.your_table
  DROP COLUMN IF EXISTS new_column;

Equivalent forms for other DDL:

  • CREATE TABLE IF NOT EXISTS …
  • DROP TABLE IF EXISTS …
  • ADD INDEX IF NOT EXISTS … / DROP INDEX IF EXISTS …
  • CREATE MATERIALIZED VIEW IF NOT EXISTS … / DROP VIEW IF EXISTS …

ClickHouse supports IF [NOT] EXISTS on all of the above. Older migrations in this directory predate the rule and are not idempotent — leave them as-is unless you're explicitly hardening one.

Naming Conventions

  • raw_ prefix for input tables (where data lands first)
  • _v1, _v2 suffixes for table versioning
  • _mv_v1 suffix for materialized views
  • _per_day, _per_month for aggregation tables

See README.md in this directory for full naming convention documentation.

Purpose

Stores time-series data for task run analytics, event streams, and performance metrics. Separate from PostgreSQL to handle high-volume writes from task execution.