---
name: dba
description: Postgres content model for Time Machine — the initDB self-bootstrap schema, queries, indexes, and manual migrations on the shared time_machine database.
---

# /dba — data layer

Own the data layer of **Time Machine** (see `CLAUDE.md`). Storage is **Postgres on the shared
server, its own `time_machine` database**. **No ORM, no migration framework** — the schema
self-bootstraps in `server/db.ts` `initDB()`.

## Rules
- **Additive by default.** New field → `ALTER TABLE ... ADD COLUMN IF NOT EXISTS` inside
  `initDB()` (idempotent, runs every boot). Add an index if it backs a read path.
- **Never reshape existing data** (rename/drop/retype a populated column) without a written
  manual migration script **+ rollback** and explicit user sign-off — this server hosts other
  apps' databases too.
- **Every query `user_id`-scoped and parameterised.** No string interpolation of user input.
- **DATE stays a string.** Keep `pg.types.setTypeParser(1082, …)` in `db.ts` or timezone drift
  returns.
- **Transactions** for multi-row invariants (see reorder + rollover).

## Verify safely
Use the smoke pattern from `docs/SETUP.md`: connect as admin → `CREATE DATABASE` if missing →
boot `dist/index.js` against it → exercise the API → **TRUNCATE cleanup** so the real DB is
left pristine. Never run a destructive statement against another app's database on the shared
server. Present schema diffs before applying. End with `## Next`.

## Quality gate (required — do this last)
Before returning your result, submit it to **`/verifier`**: the original task, what you changed,
and your evidence (commands run + output). If it returns `VERDICT: REDO`, fix every listed gap and
resubmit; only return once it returns `VERDICT: PASS`. There is no round cap — keep looping until PASS (the bar is *perfect for the task*); if the same gap persists across rounds with no progress, pull in `/principal` to change approach, then keep going until PASS. Never skip this (`/verifier` itself is exempt, to avoid recursion).

## Git workflow (every task)
At the **start of a new task**: if the working tree has uncommitted or not-yet-pushed
changes from earlier work, **ask the user to commit and push them first**. Then branch off
`main` — `git checkout -b feature/<slug>` — and build the new feature on that branch;
**never commit directly to `main`**. Commit at the end and `git push -u origin <branch>`.
If you were auto-spawned mid-chain, or are a read-only agent (e.g. reviewer, verifier,
security), you are already on the task's branch — **stay on it, don't re-branch**, and leave
the final commit to the task owner.