# TSAPI_SERIESDB_SCHEMA — canonical timeseries DB schema

**Single source of truth** for the PostgreSQL schema used by the TSAPI
timeseries database. Both client libraries target the schema defined here:

- **Python** — `TSAPI_SERIESDB_PG_PY`
- **C++** — `TSAPI_POSTGRES_CPP`

Neither project should keep its own copy of the DDL. When the schema changes,
it changes **here**, and both projects re-provision / re-test against it.

Current schema version: **1.0.0** (see [`VERSION`](VERSION); recorded at runtime
in the `meta.schema_version` table).

---

## Layout

```
TSAPI_SERIESDB_SCHEMA/
├── VERSION                      # canonical schema version string
├── run_setup.py                 # provisioner — runs the numbered files in order
├── db_config.json.example       # copy to db_config.json and edit (gitignored)
├── README.md
└── sql/
    ├── 00_extensions.sql        # pg_trgm
    ├── 01_schemas.sql           # meta / series / log schemas
    ├── 02_sequences.sql         # id sequences
    ├── 03_tables.sql            # meta.* and log.* tables
    ├── 04_indexes.sql           # indexes + registry constraints
    ├── 05_procedures.sql        # meta.* / log.* stored procedures
    ├── 06_triggers.sql          # prevent_series_drops event trigger
    ├── 07_reference_data.sql    # timezones + currencies reference data
    ├── 08_script_log.sql        # auxiliary (not part of a fresh install)
    └── migrate/                 # one-off migration scripts (run manually)
```

`run_setup.py` executes `00`–`07` in order. `08_script_log.sql` and
`sql/migrate/*.sql` are auxiliary and are **not** run by a fresh install.

---

## Provisioning a database

```bash
# 1. configure
cp db_config.json.example db_config.json      # then edit host/user/password
#    (or pass connection flags on the command line instead)

# 2. create the schema
python run_setup.py                            # uses db_config.json / defaults
python run_setup.py --host 192.168.1.7 --user claude --password claudepwd
python run_setup.py --drop-existing            # drop meta+series+log first
python run_setup.py --clean-slate              # drop ALL user objects first
```

Requires `psycopg2` and a PostgreSQL user with CREATE privileges on the target
database.

---

## What gets created

- **Schemas:** `meta` (registry + reference data), `series` (timeseries data
  tables live here), `log` (event/audit trail).
- **Registry:** `meta.series` — one row per series table, PK `table_id`,
  `UNIQUE (db_schema, table_name)`.
- **Reference tables:** `meta.currencies`, `meta.timezones`, `meta.exchanges`,
  `meta.instruments`, `meta.sessions`, `meta.holidays`, `meta.security_types`,
  `meta.schema_version`.
- **Procedures:** `meta.drop_series` / `_if_exists` / `drop_all_series`,
  `meta.update_series_last_timestamp`, `meta.refresh_series_timestamps`,
  `meta.read_series_batch[_cursor|_ohlc]`, `log.notify_event_log`,
  `log.flush_pending_to_event_log`.
- **Event trigger:** `prevent_series_drops` — blocks direct `DROP TABLE` on a
  registered series (drops must go through `meta.drop_series*`).

Series data tables have **no `UNIQUE` constraint on `timestamp`** — the index is
BRIN. Concurrent writers must serialise per-series with the advisory-lock
protocol (`pg_advisory_lock(hashtext('tsapi_pgdb.write:{schema}.{table}'))`); see
the C++ project's `planning/2026-09-02_cpp_locking_interop_plan.md`.

---

## Versioning contract

Bump [`VERSION`](VERSION) whenever `sql/` changes in a way clients must know
about, and have each client read `meta.schema_version` on connect and warn/fail
on mismatch. This turns silent schema drift into a loud error.

---

## Provenance

The `sql/` files were seeded (byte-for-byte, 2026-09-02) from the then-current
authoritative copy in `TSAPI_SERIESDB_PG_PY/tsapi_pgdb/sql/`. From this point on,
**this** directory is authoritative and the Python project should consume it
rather than keep its own copy — see the migration note in the C++ project's
`planning/` folder.

> **Known drift caught during setup:** on 2026-09-02 the remote instance
> `192.168.1.7` had `meta.sessions.exchange_id` as nullable, while the canonical
> DDL (`03_tables.sql`) defines it `NOT NULL`. Re-provision drifted databases
> from these files.