2.2 KiB
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:
- Look at
schema/and take the largest existing number, call itN. - Name your file
0(N+1)_descriptive_name.sql. - 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,_v2suffixes for table versioning_mv_v1suffix for materialized views_per_day,_per_monthfor 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.