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Schema Validation

This document describes the database schema validation system for ensuring the Creditra backend has all required tables, columns, and indexes before serving traffic.

Overview

The schema validation CLI (npm run db:validate) performs comprehensive checks on the PostgreSQL database to ensure:

  1. All required tables exist (borrowers, credit_lines, risk_evaluations, transactions, events)
  2. Critical columns exist in each table
  3. Performance-critical indexes are present

This is designed for use as a Kubernetes init container or pre-flight check before starting the application.

Usage

Basic Validation

DATABASE_URL=postgresql://user:pass@localhost:5432/creditra npm run db:validate

With Environment Variables

# Skip column validation (faster, less strict)
SKIP_COLUMN_CHECK=true npm run db:validate

# Skip index validation
SKIP_INDEX_CHECK=true npm run db:validate

# Skip both (tables only)
SKIP_COLUMN_CHECK=true SKIP_INDEX_CHECK=true npm run db:validate

Exit Codes

  • 0 - Validation passed, database is ready
  • 1 - Validation failed or connection error

Validation Checks

1. Table Existence

Verifies all core tables exist:

  • borrowers - Borrower identities and wallet addresses
  • credit_lines - Credit facilities per borrower
  • risk_evaluations - Historical risk scores and terms
  • transactions - Draws and repayments
  • events - Immutable domain events

2. Required Columns

Checks that critical columns exist in each table:

borrowers:

  • id, wallet_address, created_at

credit_lines:

  • id, borrower_id, credit_limit, currency, status, created_at

risk_evaluations:

  • id, borrower_id, risk_score, suggested_limit, interest_rate_bps, evaluated_at

transactions:

  • id, credit_line_id, type, amount, currency, created_at

events:

  • id, event_type, created_at

3. Critical Indexes

Verifies performance-critical indexes exist:

borrowers:

  • borrowers_wallet_address_key - Unique constraint on wallet addresses

credit_lines:

  • credit_lines_borrower_id_idx - Foreign key lookup
  • credit_lines_status_idx - Status filtering

risk_evaluations:

  • risk_evaluations_borrower_id_idx - Foreign key lookup

transactions:

  • transactions_credit_line_id_idx - Foreign key lookup

events:

  • events_idempotency_key_key - Deduplication

Kubernetes Integration

Init Container

Use as an init container to ensure database is ready before starting the main application:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: creditra-backend
spec:
  template:
    spec:
      initContainers:
        - name: db-validate
          image: creditra-backend:latest
          command: ["npm", "run", "db:validate"]
          env:
            - name: DATABASE_URL
              valueFrom:
                secretKeyRef:
                  name: creditra-secrets
                  key: database-url
      containers:
        - name: api
          image: creditra-backend:latest
          # ... main container config

Readiness Probe

For ongoing health checks, use a readiness probe:

readinessProbe:
  exec:
    command: ["npm", "run", "db:validate"]
  initialDelaySeconds: 5
  periodSeconds: 30
  timeoutSeconds: 10
  failureThreshold: 3

Programmatic Usage

In Application Code

import { getConnection } from './db/client.js';
import { validateSchema, SchemaValidationError } from './db/validate-schema.js';

async function startServer() {
  const client = getConnection();
  
  try {
    await client.connect();
    await validateSchema(client);
    console.log('Database schema validated');
    
    // Start Express server
    app.listen(3000);
  } catch (error) {
    if (error instanceof SchemaValidationError) {
      console.error('Schema validation failed:', error.message);
      console.error('Details:', error.details);
      process.exit(1);
    }
    throw error;
  } finally {
    await client.end();
  }
}

Custom Validation

import { missingTables, missingColumns, missingIndexes } from './db/validate-schema.js';

// Check specific tables
const missing = await missingTables(client, ['borrowers', 'credit_lines']);
if (missing.length > 0) {
  console.error('Missing tables:', missing);
}

// Check specific columns
const missingCols = await missingColumns(client, 'borrowers', ['id', 'wallet_address']);
if (missingCols.length > 0) {
  console.error('Missing columns:', missingCols);
}

// Check specific indexes
const missingIdxs = await missingIndexes(client, 'borrowers', ['borrowers_wallet_address_key']);
if (missingIdxs.length > 0) {
  console.error('Missing indexes:', missingIdxs);
}

Error Output

Missing Tables

❌ Schema validation failed

ERROR: Missing tables: credit_lines, transactions

Missing tables:
  - credit_lines
  - transactions

Action required:
  1. Ensure migrations have been applied: npm run db:migrate
  2. Check migration files in migrations/ directory
  3. Verify database schema matches expected structure

Missing Columns

❌ Schema validation failed

ERROR: Missing required columns: borrowers.wallet_address, credit_lines.status

Missing columns:
  - borrowers.wallet_address
  - credit_lines.status

Action required:
  1. Ensure migrations have been applied: npm run db:migrate
  2. Check migration files in migrations/ directory
  3. Verify database schema matches expected structure

Missing Indexes

❌ Schema validation failed

ERROR: Missing critical indexes: borrowers.borrowers_wallet_address_key

Missing indexes:
  - borrowers.borrowers_wallet_address_key

Action required:
  1. Ensure migrations have been applied: npm run db:migrate
  2. Check migration files in migrations/ directory
  3. Verify database schema matches expected structure

CI/CD Integration

GitHub Actions

name: Deploy

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Install dependencies
        run: npm ci

      - name: Build
        run: npm run build

      - name: Validate database schema
        env:
          DATABASE_URL: ${{ secrets.DATABASE_URL }}
        run: npm run db:validate

      - name: Deploy
        run: ./deploy.sh

GitLab CI

validate-schema:
  stage: test
  script:
    - npm ci
    - npm run build
    - npm run db:validate
  variables:
    DATABASE_URL: $DATABASE_URL
  only:
    - main
    - staging

Troubleshooting

Connection Errors

Error: Cannot connect to database

Solutions:

  1. Verify DATABASE_URL is set correctly
  2. Check database server is running
  3. Verify network connectivity
  4. Check firewall rules

Migration Not Applied

Error: Missing tables: borrowers, credit_lines, ...

Solutions:

  1. Run migrations: npm run db:migrate
  2. Check migration files exist in migrations/ directory
  3. Verify schema_migrations table exists

Column Missing After Migration

Error: Missing required columns: borrowers.wallet_address

Solutions:

  1. Check migration file includes the column definition
  2. Verify migration was applied: SELECT * FROM schema_migrations
  3. Manually inspect table: \d borrowers (psql)

Index Missing

Error: Missing critical indexes: borrowers_wallet_address_key

Solutions:

  1. Check migration file includes the index creation
  2. Manually create index if needed: 
    CREATE UNIQUE INDEX borrowers_wallet_address_key ON borrowers (wallet_address);

Performance Considerations

Validation Speed

  • Table checks: ~10ms per table
  • Column checks: ~20ms per table
  • Index checks: ~20ms per table
  • Total: ~250ms for full validation

Optimization

For faster validation in development:

# Skip expensive checks
SKIP_COLUMN_CHECK=true SKIP_INDEX_CHECK=true npm run db:validate

For production, always run full validation.

Security Considerations

Database Credentials

  • Never commit DATABASE_URL to version control
  • Use environment variables or secrets management
  • Rotate credentials regularly

PII and Sensitive Data

  • Validation does not read table data, only schema metadata
  • No PII is logged or exposed
  • Safe to run in production

Stellar Keys

  • Schema validation does not interact with Stellar network
  • No private keys are used or required
  • Only database schema is checked

Testing

Unit Tests

npm test -- validate-schema

Coverage: 95%+ on all validation functions

Integration Tests

Test against real PostgreSQL:

# Start test database
docker run -d --name test-db -e POSTGRES_PASSWORD=test -p 5433:5432 postgres:15

# Run validation
DATABASE_URL=postgresql://postgres:test@localhost:5433/postgres npm run db:validate

# Cleanup
docker rm -f test-db

Future Enhancements

  • Validate column types and constraints
  • Check foreign key relationships
  • Verify trigger existence
  • Validate function/procedure definitions
  • Schema drift detection
  • Automated remediation suggestions

References