projection-patterns

You build queryable read models from event streams by implementing projections that materialize domain events into structured views. This approach enables fast insights for CQRS-based systems, real-time dashboards, and analytics across multiple storage backends.

Available projection types for materializing domain events include Live, Catchup, Persistent, and Inline projections. Each type handles event sourcing read models differently, supporting various event store wiring and checkpoint mechanisms for reliable view generation.

Idempotent replay during projection rebuilds is handled through context-aware projection logic combined with a checkpoint mechanism. This ensures recoverability and auditing across storage backends by tracking processed domain events accurately without duplication.

Yes, an event store interface is required to implement CQRS projections. The event store feeds domain events into the projector, which requires a checkpoint mechanism and context-aware logic to process entity types and event types for reliable read model updates.

The best way to structure aggregated views and multi-table read models is using provided projection templates. These templates cover basic projectors, order summaries, and search projections, accelerating implementation by wiring event stores directly to read model storage.

Projection read models fall behind during catchup processing when checkpoint mechanisms fail to track domain events properly. Ensuring context-aware projection logic handles entity types and event types idempotently across your storage backend restores recoverability and synchronization.