CQRS
On this page
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.