Technical Glossary
CQRS (Command Query Responsibility Segregation)
Exact Definition
CQRS is an architectural pattern that separates database read (query) operations from write (command) operations into distinct models, allowing each side to be optimized, scaled, and secured independently.
Architectural Deep Dive
In a standard CRUD application, read and write operations compete for the same database resources. CQRS splits the data model: commands mutate state through an OLTP write database, while queries read from an optimized read replica or materialized view. This is particularly valuable in ERP systems where real-time reporting queries (e.g., 'show all orders in the last 30 days') would otherwise lock the same tables processing new order writes.
The ERPStack Approach
We implement CQRS using PostgreSQL read replicas for analytics dashboards, keeping writes on the primary instance. This allows real-time reporting without impacting transaction throughput on the write path.