CQRS-DETAIL

Write/read model separation.

Definition

CQRS allows independent optimisation of write performance (PostgreSQL transactional) and read performance (Elasticsearch full-text, Redis cache). Often coupled with Event Sourcing (append-only audit log) and Eventual Consistency (ms-to-seconds write→read latency). Ideal for reads ≫ writes systems.

Origin

CQS originally proposed by Bertrand Meyer (Eiffel, 1988) ; CQRS formalised by Greg Young in his blog in 2010.

Example in context

An EDI hub separates its writes (kafka → postgres) from its reads (Elasticsearch) to serve real-time operational dashboards.

Related terms

• Event Storming — design methodology.