Replace the per-cell parquet cache with TimescaleDB hypertables as the
production backend for the raw daily climate record, and drop pg_duckdb.
Parquet stays the backend whenever THERMOGRAPH_DATABASE_URL is not a
Postgres URL (dev, tests, offline tooling), the same dialect switch the
accounts DB and derived store already use, so CI stays Postgres-free.
- data/climate_store.py: psycopg + polars bridge over climate_history
(a hypertable), climate_recent, and climate_sync (per-cell freshness).
Reads via pl.read_database, writes via COPY + ON CONFLICT upsert;
fail-soft to a cache miss so a DB hiccup degrades to upstream refetch.
- data/climate.py: route every cache/mtime touchpoint through a backend
dispatch. recent_stamp becomes int(recent_synced_at) on Postgres; the
stale-serve path still avoids bumping it, so derived-payload tokens
invalidate on exactly the same events as before.
- alembic 0002: CREATE EXTENSION timescaledb plus the hypertable schema
(compression policy on year-old chunks), guarded to no-op off Postgres.
- migrate_cache_to_pg.py (make migrate-cache): idempotent backfill of the
parquet cache into the hypertables, preserving file mtimes as sync
timestamps so recent_stamp is unchanged across cutover.
- db image -> stock timescale/timescaledb:latest-pg18; drop the custom
pg_duckdb Dockerfile, the read-only /parquet mount, and the duckdb
tuning GUC. Docs updated for the new backend and cutover.
Co-authored-by: Claude <noreply@anthropic.com>
Run Thermograph as a docker-compose stack (app + Postgres 18) and standardize the
data layer on Postgres, while keeping the test suite on SQLite.
- accounts/db.py: DSN-driven engines. On Postgres, a per-worker read-write +
read-only asyncpg pair (the RO engine pins read-only transactions, used by the
pure-GET endpoints) plus a sync psycopg engine for the notifier thread; the
SQLite path is preserved for tests/local (selected when THERMOGRAPH_DATABASE_URL
is unset). models.py: boolean server_default -> sa.false().
- store.py / metrics.py: dialect-flexible — Postgres UNLOGGED tables via psycopg
when configured, else the existing raw-sqlite3 paths byte-for-byte; sync
interfaces and every fail-soft contract preserved.
- Alembic (backend/alembic/) manages the accounts schema; the container entrypoint
runs `alembic upgrade head` before uvicorn (4 workers). migrate_accounts_to_pg.py
copies the accounts data SQLite->PG through the ORM (UUID/bool/JSON coerced),
skips access_token, and resets identity sequences.
- Dockerfile + docker-compose.yml: app image (uvicorn, 4 workers, loopback 8137)
and a Postgres 18 db (2 CPUs) running pg_duckdb (deploy/db/) so the parquet
climate cache is queryable in-DB via read_parquet('/parquet/cache/*.parquet').
- deploy.sh/thermograph.service rewired to manage the compose stack; env example,
Makefile targets (up/down/db-up), and deploy/POSTGRES-MIGRATION.md cutover runbook.
Tests stay on SQLite (dialect fallback) — 323 pass. The full Postgres stack was
verified via docker compose: alembic migrations, register/login, the RO endpoint,
store/metrics round-trips, and the accounts data migration.
