---
phase: 01-core-infrastructure-security
plan: 02
subsystem: database
tags: [postgresql, sqlalchemy, alembic, asyncpg, docker]

# Dependency graph
requires:
  - phase: 01-01
    provides: FastAPI project structure, pydantic-settings configuration
provides:
  - PostgreSQL database with Docker container
  - Async SQLAlchemy session factory with connection pooling
  - Alembic migration infrastructure for async
  - Build model for tracking ISO generation jobs
affects: [01-03, 01-04, 01-05, 02, 03]

# Tech tracking
tech-stack:
  added: [postgresql:16-alpine, asyncpg, alembic]
  patterns: [async-session-management, connection-pooling, uuid-primary-keys]

key-files:
  created:
    - backend/app/db/session.py
    - backend/app/db/base.py
    - backend/app/db/models/build.py
    - backend/alembic/env.py
    - docker-compose.yml
  modified:
    - .env.example

key-decisions:
  - "Use port 5433 for PostgreSQL to avoid conflict with existing postgres containers"
  - "Connection pool: pool_size=10, max_overflow=20, pool_recycle=1800 (from research)"
  - "Build model uses UUID primary key and SHA-256 config_hash for caching"

patterns-established:
  - "Async session factory pattern with get_db() dependency"
  - "Alembic async migrations using asyncio.run()"
  - "Models inherit from DeclarativeBase and are imported in env.py"

# Metrics
duration: 6min
completed: 2026-01-25
---

# Phase 1 Plan 2: PostgreSQL Database Setup Summary

**PostgreSQL 16 with async SQLAlchemy session factory, Alembic migrations, and Build tracking model**

## Performance

- **Duration:** 6 min
- **Started:** 2026-01-25T20:06:20Z
- **Completed:** 2026-01-25T20:12:01Z
- **Tasks:** 2
- **Files modified:** 13

## Accomplishments

- PostgreSQL 16 running in Docker container with health checks (port 5433)
- Async SQLAlchemy engine with production-grade connection pooling
- Alembic configured for async migrations with autogenerate support
- Build model created with UUID primary key, status enum, and indexes

## Task Commits

Each task was committed atomically:

1. **Task 1: Set up PostgreSQL with Docker and async session factory** - `fbcd2bb` (feat)
2. **Task 2: Configure Alembic and create Build model** - `c261664` (feat)

## Files Created/Modified

- `docker-compose.yml` - PostgreSQL 16 container configuration (port 5433)
- `backend/app/db/session.py` - Async engine and session factory with pooling
- `backend/app/db/base.py` - SQLAlchemy 2.0 DeclarativeBase
- `backend/app/db/__init__.py` - Database package exports
- `backend/app/db/models/build.py` - Build tracking model with status enum
- `backend/app/db/models/__init__.py` - Models package exports
- `backend/alembic.ini` - Alembic configuration
- `backend/alembic/env.py` - Async migration environment
- `backend/alembic/versions/de1460a760b0_create_build_table.py` - Initial migration
- `.env.example` - Updated DATABASE_URL to port 5433

## Decisions Made

1. **Port 5433 instead of 5432** - Another PostgreSQL container was using port 5432; used 5433 to avoid conflict
2. **Connection pooling settings** - Applied research recommendations: pool_size=10, max_overflow=20, pool_recycle=1800, pool_pre_ping=True
3. **Build model design** - UUID primary key for security, config_hash for deterministic caching, status enum for queue management

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

- Port 5432 was already allocated by another postgres container (moai-postgres)
- Resolution: Changed to port 5433 in docker-compose.yml and updated all configurations

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- Database infrastructure complete and running
- Ready for 01-03-PLAN.md (Security middleware)
- Build model available for queue and worker implementation in Phase 3

---
*Phase: 01-core-infrastructure-security*
*Completed: 2026-01-25*