Advanced Read Model Patterns

Advanced Read Model Patterns

What You’ll Build: Advanced read models with denormalization, custom projections, and query optimization.

Overview

This tutorial covers advanced read model patterns including multi-aggregate projections, denormalization strategies, custom projection logic, and performance optimization techniques.

For detailed implementation guidance, refer to the platform examples and documentation:

• Event-Sourced Service Example
• Read Models Concept
• Performance Guide

Key Topics Covered

1. Multi-Aggregate Projections: Combine events from multiple aggregates
2. Denormalization: Pre-compute joins for fast queries
3. Custom Projection Logic: Complex transformations
4. Indexing Strategies: Optimize query performance
5. Catchup Processes: Rebuild projections from events
6. Versioning: Handle schema changes

Advanced Patterns

Pattern 1: Customer Order History

Project orders and related data into customer read model:

@ReadModel({ tableName: 'customer_summary' })
export class CustomerSummaryReadModel {
  @MapFromEvent('CustomerCreated')
  customerId!: string;

  // Denormalized from Order events
  totalOrders: number = 0;
  totalSpent: number = 0;
  lastOrderDate?: Date;
  favoriteProducts: string[] = [];
}

Pattern 2: Product Analytics

Aggregate product data across orders:

@ReadModel({ tableName: 'product_analytics' })
export class ProductAnalyticsReadModel {
  productId!: string;
  totalSold: number = 0;
  revenue: number = 0;
  averageRating: number = 0;
  topBuyingCustomers: string[] = [];
}

Next Steps

• Performance Optimization
• Saga Orchestration

Additional Resources

• Database Optimization
• Query Patterns