---
phase: 14-postgresql-migration
plan: 01
subsystem: database
tags: [postgresql, drizzle-orm, pglite, postgres-js, migration]

requires:
  - phase: 13-setup-impact-preview
    provides: "Complete SQLite-based application"
provides:
  - "PostgreSQL schema definitions (13 tables via pg-core)"
  - "postgres.js database connection with DATABASE_URL"
  - "PGlite-based async test helper"
  - "Initial PostgreSQL migration (drizzle-pg/)"
  - "Async seed function"
affects: [14-02, 14-03, 14-04, 14-05, 14-06]

tech-stack:
  added: [postgres (postgres.js driver), "@electric-sql/pglite"]
  patterns: ["pgTable schema definitions", "async createTestDb() with PGlite", "DATABASE_URL environment variable for connection"]

key-files:
  created: ["drizzle-pg/0000_fuzzy_shiva.sql"]
  modified: ["src/db/schema.ts", "src/db/index.ts", "src/db/migrate.ts", "src/db/seed.ts", "drizzle.config.ts", "tests/helpers/db.ts", "package.json", "biome.json"]

key-decisions:
  - "Used postgres.js (not pg/node-postgres) as PostgreSQL driver for Drizzle ORM"
  - "PGlite for in-memory test databases replacing bun:sqlite :memory:"
  - "Migration output directory drizzle-pg/ separate from old drizzle/ directory"

patterns-established:
  - "All schema tables use pgTable with serial primary keys (except settings/sessions with text PKs)"
  - "Timestamps use native timestamp type with defaultNow() instead of integer mode:timestamp"
  - "Test databases created via async createTestDb() returning PGlite-backed Drizzle instance"

requirements-completed: [DB-01, DB-03]

duration: 3min
completed: 2026-04-04
---

# Phase 14 Plan 01: Database Foundation Summary

**PostgreSQL schema with 13 pgTable definitions, postgres.js connection, PGlite test infrastructure, and initial migration**

## Performance

- **Duration:** 3 min
- **Started:** 2026-04-04T10:15:43Z
- **Completed:** 2026-04-04T10:19:11Z
- **Tasks:** 2
- **Files modified:** 10

## Accomplishments
- Rewrote all 13 table definitions from sqliteTable to pgTable with correct type mappings (serial, timestamp, doublePrecision, boolean)
- Established postgres.js connection with DATABASE_URL environment variable
- Created async PGlite test helper that applies migrations and seeds in-memory
- Generated initial PostgreSQL migration with 13 CREATE TABLE statements
- Zero SQLite references remain in database layer files

## Task Commits

Each task was committed atomically:

1. **Task 1: Install dependencies and rewrite schema + DB config files** - `3724cf8` (feat)
2. **Task 2: Rewrite test helper and generate initial PostgreSQL migration** - `3bf1fd7` (feat)

## Files Created/Modified
- `src/db/schema.ts` - 13 PostgreSQL table definitions using drizzle-orm/pg-core
- `src/db/index.ts` - postgres.js connection with DATABASE_URL
- `src/db/migrate.ts` - postgres-js migrator targeting drizzle-pg/
- `src/db/seed.ts` - Async seed function for default category
- `drizzle.config.ts` - PostgreSQL dialect config with drizzle-pg/ output
- `tests/helpers/db.ts` - Async PGlite-backed createTestDb()
- `package.json` - Added postgres, @electric-sql/pglite; removed better-sqlite3
- `biome.json` - Added drizzle-pg/ to ignore list
- `drizzle-pg/0000_fuzzy_shiva.sql` - Initial migration with 13 tables

## Decisions Made
- Used postgres.js driver (lightweight, ESM-native, good Drizzle integration) over node-postgres
- PGlite creates ephemeral in-memory Postgres for tests -- no external DB needed
- Separate migration directory (drizzle-pg/) to avoid conflicts with old SQLite migrations (drizzle/)
- Added drizzle-pg/ to biome ignore since it contains generated files

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] Added drizzle-pg/ to biome ignore list**
- **Found during:** Task 2 (migration generation)
- **Issue:** Generated drizzle-pg/ JSON snapshot failed biome formatting (2-space vs tab indent)
- **Fix:** Added "!drizzle-pg" to biome.json files.includes array (matching existing "!drizzle" pattern)
- **Files modified:** biome.json
- **Verification:** `bun run lint` passes clean
- **Committed in:** 3bf1fd7 (Task 2 commit)

---

**Total deviations:** 1 auto-fixed (1 blocking)
**Impact on plan:** Necessary to maintain passing lint. No scope creep.

## Issues Encountered
- PGlite smoke test exits with code 99 when no explicit `process.exit(0)` is called -- this is a known PGlite cleanup behavior, not a real error. Adding explicit exit resolves it.

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness
- Schema and test infrastructure ready for service layer conversion (Plan 14-02)
- All services can now be updated to use async Drizzle operations against PostgreSQL types
- PGlite test helper available for all test files to migrate to

## Self-Check: PASSED

All 7 key files verified present. Both task commits (3724cf8, 3bf1fd7) verified in git log.

---
*Phase: 14-postgresql-migration*
*Completed: 2026-04-04*