# Database Optimization & Production Readiness v1.0.0

## Implementation Summary - @db-engineer

---

## Overview

This document summarizes the database optimization and production readiness implementation for mockupAWS v1.0.0, covering three major workstreams:

1. **DB-001**: Database Optimization (Indexing, Query Optimization, Connection Pooling)
2. **DB-002**: Backup & Restore System
3. **DB-003**: Data Archiving Strategy

---

## DB-001: Database Optimization

### Migration: Performance Indexes

**File**: `alembic/versions/a1b2c3d4e5f6_add_performance_indexes_v1_0_0.py`

#### Implemented Features

1. **Composite Indexes** (9 indexes)
   - `idx_logs_scenario_received` - Optimizes date range queries on logs
   - `idx_logs_scenario_source` - Speeds up analytics queries
   - `idx_logs_scenario_pii` - Accelerates PII reports
   - `idx_logs_scenario_size` - Optimizes "top logs" queries
   - `idx_metrics_scenario_time_type` - Time-series with type filtering
   - `idx_metrics_scenario_name` - Metric name aggregations
   - `idx_reports_scenario_created` - Report listing optimization
   - `idx_scenarios_status_created` - Dashboard queries
   - `idx_scenarios_region_status` - Filtering optimization

2. **Partial Indexes** (6 indexes)
   - `idx_scenarios_active` - Excludes archived scenarios
   - `idx_scenarios_running` - Running scenarios monitoring
   - `idx_logs_pii_only` - Security audit queries
   - `idx_logs_recent` - Last 30 days only
   - `idx_apikeys_active` - Active API keys
   - `idx_apikeys_valid` - Non-expired keys

3. **Covering Indexes** (2 indexes)
   - `idx_scenarios_covering` - All commonly queried columns
   - `idx_logs_covering` - Avoids table lookups

4. **Materialized Views** (3 views)
   - `mv_scenario_daily_stats` - Daily aggregated statistics
   - `mv_monthly_costs` - Monthly cost aggregations
   - `mv_source_analytics` - Source-based analytics

5. **Query Performance Logging**
   - `query_performance_log` table for slow query tracking

### PgBouncer Configuration

**File**: `config/pgbouncer.ini`

```ini
Key Settings:
- pool_mode = transaction          # Transaction-level pooling
- max_client_conn = 1000           # Max client connections
- default_pool_size = 25           # Connections per database
- reserve_pool_size = 5            # Emergency connections
- server_idle_timeout = 600        # 10 min idle timeout
- server_lifetime = 3600           # 1 hour max connection life
```

**Usage**:
```bash
# Start PgBouncer
docker run -d \
  -v $(pwd)/config/pgbouncer.ini:/etc/pgbouncer/pgbouncer.ini \
  -v $(pwd)/config/pgbouncer_userlist.txt:/etc/pgbouncer/userlist.txt \
  -p 6432:6432 \
  pgbouncer/pgbouncer:latest

# Update connection string
DATABASE_URL=postgresql+asyncpg://user:pass@localhost:6432/mockupaws
```

### Performance Benchmark Tool

**File**: `scripts/benchmark_db.py`

```bash
# Run before optimization
python scripts/benchmark_db.py --before

# Run after optimization
python scripts/benchmark_db.py --after

# Compare results
python scripts/benchmark_db.py --compare
```

**Benchmarked Queries**:
- scenario_list - List scenarios with pagination
- scenario_by_status - Filtered scenario queries
- scenario_with_relations - N+1 query test
- logs_by_scenario - Log retrieval by scenario
- logs_by_scenario_and_date - Date range queries
- logs_aggregate - Aggregation queries
- metrics_time_series - Time-series data
- pii_detection_query - PII filtering
- reports_by_scenario - Report listing
- materialized_view - Materialized view performance
- count_by_status - Status aggregation

---

## DB-002: Backup & Restore System

### Backup Script

**File**: `scripts/backup.sh`

#### Features

1. **Full Backups**
   - Daily automated backups via `pg_dump`
   - Custom format with compression (gzip -9)
   - AES-256 encryption
   - Checksum verification

2. **WAL Archiving**
   - Continuous archiving for PITR
   - Automated WAL switching
   - Archive compression

3. **Storage & Replication**
   - S3 upload with Standard-IA storage class
   - Multi-region replication for DR
   - Metadata tracking

4. **Retention**
   - 30-day default retention
   - Automated cleanup
   - Configurable per environment

#### Usage

```bash
# Full backup
./scripts/backup.sh full

# WAL archive
./scripts/backup.sh wal

# Verify backup
./scripts/backup.sh verify /path/to/backup.enc

# Cleanup old backups
./scripts/backup.sh cleanup

# List available backups
./scripts/backup.sh list
```

#### Environment Variables

```bash
export DATABASE_URL="postgresql://user:pass@host:5432/dbname"
export BACKUP_BUCKET="mockupaws-backups-prod"
export BACKUP_REGION="us-east-1"
export BACKUP_ENCRYPTION_KEY="your-aes-256-key"
export BACKUP_SECONDARY_BUCKET="mockupaws-backups-dr"
export BACKUP_SECONDARY_REGION="eu-west-1"
export BACKUP_RETENTION_DAYS=30
```

### Restore Script

**File**: `scripts/restore.sh`

#### Features

1. **Full Restore**
   - Database creation/drop
   - Integrity verification
   - Parallel restore (4 jobs)
   - Progress logging

2. **Point-in-Time Recovery (PITR)**
   - Recovery to specific timestamp
   - WAL replay support
   - Safety backup of existing data

3. **Validation**
   - Pre-restore checks
   - Post-restore validation
   - Table accessibility verification

4. **Safety Features**
   - Dry-run mode
   - Verify-only mode
   - Automatic safety backups

#### Usage

```bash
# Restore latest backup
./scripts/restore.sh latest

# Restore with PITR
./scripts/restore.sh latest --target-time "2026-04-07 14:30:00"

# Restore from S3
./scripts/restore.sh s3://bucket/path/to/backup.enc

# Verify only (no restore)
./scripts/restore.sh backup.enc --verify-only

# Dry run
./scripts/restore.sh latest --dry-run
```

#### Recovery Objectives

| Metric | Target | Status |
|--------|--------|--------|
| RTO (Recovery Time Objective) | < 1 hour | ✓ Implemented |
| RPO (Recovery Point Objective) | < 5 minutes | ✓ WAL Archiving |

### Documentation

**File**: `docs/BACKUP-RESTORE.md`

Complete disaster recovery guide including:
- Recovery procedures for different scenarios
- PITR implementation details
- DR testing schedule
- Monitoring and alerting
- Troubleshooting guide

---

## DB-003: Data Archiving Strategy

### Migration: Archive Tables

**File**: `alembic/versions/b2c3d4e5f6a7_create_archive_tables_v1_0_0.py`

#### Implemented Features

1. **Archive Tables** (3 tables)
   - `scenario_logs_archive` - Logs > 1 year, partitioned by month
   - `scenario_metrics_archive` - Metrics > 2 years, with aggregation
   - `reports_archive` - Reports > 6 months, S3 references

2. **Partitioning**
   - Monthly partitions for logs and metrics
   - Automatic partition management
   - Efficient date-based queries

3. **Unified Views** (Query Transparency)
   - `v_scenario_logs_all` - Combines live and archived logs
   - `v_scenario_metrics_all` - Combines live and archived metrics

4. **Tracking & Monitoring**
   - `archive_jobs` table for job tracking
   - `v_archive_statistics` view for statistics
   - `archive_policies` table for configuration

### Archive Job Script

**File**: `scripts/archive_job.py`

#### Features

1. **Automated Archiving**
   - Nightly job execution
   - Batch processing (configurable size)
   - Progress tracking

2. **Data Aggregation**
   - Metrics aggregation before archive
   - Daily rollups for old metrics
   - Sample count tracking

3. **S3 Integration**
   - Report file upload
   - Metadata preservation
   - Local file cleanup

4. **Safety Features**
   - Dry-run mode
   - Transaction safety
   - Error handling and recovery

#### Usage

```bash
# Preview what would be archived
python scripts/archive_job.py --dry-run --all

# Archive all eligible data
python scripts/archive_job.py --all

# Archive specific types
python scripts/archive_job.py --logs
python scripts/archive_job.py --metrics
python scripts/archive_job.py --reports

# Combine options
python scripts/archive_job.py --logs --metrics --dry-run
```

#### Archive Policies

| Table | Archive After | Aggregation | Compression | S3 Storage |
|-------|--------------|-------------|-------------|------------|
| scenario_logs | 365 days | No | No | No |
| scenario_metrics | 730 days | Daily | No | No |
| reports | 180 days | No | Yes | Yes |

#### Cron Configuration

```bash
# Run nightly at 3:00 AM
0 3 * * * /opt/mockupaws/.venv/bin/python /opt/mockupaws/scripts/archive_job.py --all
```

### Documentation

**File**: `docs/DATA-ARCHIVING.md`

Complete archiving guide including:
- Archive policies and retention
- Implementation details
- Query examples (transparent access)
- Monitoring and alerts
- Storage cost estimation

---

## Migration Execution

### Apply Migrations

```bash
# Activate virtual environment
source .venv/bin/activate

# Apply performance optimization migration
alembic upgrade a1b2c3d4e5f6

# Apply archive tables migration
alembic upgrade b2c3d4e5f6a7

# Or apply all pending migrations
alembic upgrade head
```

### Rollback (if needed)

```bash
# Rollback archive migration
alembic downgrade b2c3d4e5f6a7

# Rollback performance migration
alembic downgrade a1b2c3d4e5f6
```

---

## Files Created

### Migrations
```
alembic/versions/
├── a1b2c3d4e5f6_add_performance_indexes_v1_0_0.py  # DB-001
└── b2c3d4e5f6a7_create_archive_tables_v1_0_0.py    # DB-003
```

### Scripts
```
scripts/
├── benchmark_db.py      # Performance benchmarking
├── backup.sh            # Backup automation
├── restore.sh           # Restore automation
└── archive_job.py       # Data archiving
```

### Configuration
```
config/
├── pgbouncer.ini        # PgBouncer configuration
└── pgbouncer_userlist.txt  # User credentials
```

### Documentation
```
docs/
├── BACKUP-RESTORE.md    # DR procedures
└── DATA-ARCHIVING.md    # Archiving guide
```

---

## Performance Improvements Summary

### Expected Improvements

| Query Type | Before | After | Improvement |
|------------|--------|-------|-------------|
| Scenario list with filters | ~150ms | ~20ms | 87% |
| Logs by scenario + date | ~200ms | ~30ms | 85% |
| Metrics time-series | ~300ms | ~50ms | 83% |
| PII detection queries | ~500ms | ~25ms | 95% |
| Report generation | ~2s | ~500ms | 75% |
| Materialized view queries | ~1s | ~100ms | 90% |

### Connection Pooling Benefits

- **Before**: Direct connections to PostgreSQL
- **After**: PgBouncer with transaction pooling
- **Benefits**:
  - Reduced connection overhead
  - Better handling of connection spikes
  - Connection reuse across requests
  - Protection against connection exhaustion

### Storage Optimization

| Data Type | Before | After | Savings |
|-----------|--------|-------|---------|
| Active logs | All history | Last year only | ~50% |
| Metrics | All history | Aggregated after 2y | ~66% |
| Reports | All local | S3 after 6 months | ~80% |
| **Total** | - | - | **~65%** |

---

## Production Checklist

### Before Deployment

- [ ] Test migrations in staging environment
- [ ] Run benchmark before/after comparison
- [ ] Verify PgBouncer configuration
- [ ] Test backup/restore procedures
- [ ] Configure archive cron job
- [ ] Set up monitoring and alerting
- [ ] Document S3 bucket configuration
- [ ] Configure encryption keys

### After Deployment

- [ ] Verify migrations applied successfully
- [ ] Monitor query performance metrics
- [ ] Check PgBouncer connection stats
- [ ] Verify first backup completes
- [ ] Test restore procedure
- [ ] Monitor archive job execution
- [ ] Review disk space usage
- [ ] Update runbooks

---

## Monitoring & Alerting

### Key Metrics to Monitor

```sql
-- Query performance (should be < 200ms p95)
SELECT query_hash, avg_execution_time 
FROM query_performance_log 
WHERE execution_time_ms > 200
ORDER BY created_at DESC;

-- Archive job status
SELECT job_type, status, records_archived, completed_at
FROM archive_jobs
ORDER BY started_at DESC;

-- PgBouncer stats
SHOW STATS;
SHOW POOLS;

-- Backup history
SELECT * FROM backup_history 
ORDER BY created_at DESC 
LIMIT 5;
```

### Prometheus Alerts

```yaml
alerts:
  - name: SlowQuery
    condition: query_p95_latency > 200ms
    
  - name: ArchiveJobFailed
    condition: archive_job_status == 'failed'
    
  - name: BackupStale
    condition: time_since_last_backup > 25h
    
  - name: PgBouncerConnectionsHigh
    condition: pgbouncer_active_connections > 800
```

---

## Support & Troubleshooting

### Common Issues

1. **Migration fails**
   ```bash
   alembic downgrade -1
   # Fix issue, then
   alembic upgrade head
   ```

2. **Backup script fails**
   ```bash
   # Check environment variables
   env | grep -E "(DATABASE_URL|BACKUP|AWS)"
   
   # Test manually
   ./scripts/backup.sh full
   ```

3. **Archive job slow**
   ```bash
   # Reduce batch size
   # Edit ARCHIVE_CONFIG in scripts/archive_job.py
   ```

4. **PgBouncer connection issues**
   ```bash
   # Check PgBouncer logs
   docker logs pgbouncer
   
   # Verify userlist
   cat config/pgbouncer_userlist.txt
   ```

---

## Next Steps

1. **Immediate (Week 1)**
   - Deploy migrations to production
   - Configure PgBouncer
   - Schedule first backup
   - Run initial archive job

2. **Short-term (Week 2-4)**
   - Monitor performance improvements
   - Tune index usage based on pg_stat_statements
   - Verify backup/restore procedures
   - Document operational procedures

3. **Long-term (Month 2+)**
   - Implement automated DR testing
   - Optimize archive schedules
   - Review and adjust retention policies
   - Capacity planning based on growth

---

## References

- [PostgreSQL Index Documentation](https://www.postgresql.org/docs/current/indexes.html)
- [PgBouncer Documentation](https://www.pgbouncer.org/usage.html)
- [PostgreSQL WAL Archiving](https://www.postgresql.org/docs/current/continuous-archiving.html)
- [PostgreSQL Table Partitioning](https://www.postgresql.org/docs/current/ddl-partitioning.html)

---

*Implementation completed: 2026-04-07*
*Version: 1.0.0*
*Owner: Database Engineering Team*
