# CQRS

Record: `arch:command-query-responsibility-segregation`
Kind: pattern
Layer: [Execution Core](https://banes-lab.com/records/layer/execution-core.md)
Severity: contextual
Scope: application, data access
Aliases: CQRS
Canonical: https://banes-lab.com/ontology#arch-command-query-responsibility-segregation

## Repair

- Refactored by: Split Command and Query Models
- Detected by: command/query side-effect violations
- Violated by: queries mutating state, commands returning complex read models
- Measured by: read/write separation compliance
- Enforced by: handler conventions, [tests](https://banes-lab.com/records/lex/tests.md)

## requires

- [Command/Query Separation](https://banes-lab.com/records/lex/command-query-separation.md)

## reinforces

- [Scalability](https://banes-lab.com/records/arch/scalability.md)
- [Event Sourcing](https://banes-lab.com/records/arch/event-sourcing.md)

## enables

- [Read/Write Model Optimization](https://banes-lab.com/records/lex/read-write-model-optimization.md)

## conflicts-with

- [Unified CRUD Model](https://banes-lab.com/records/lex/unified-crud-model.md)

## tensions-with

- [Eventual Consistency](https://banes-lab.com/records/arch/eventual-consistency.md)

## tensions

- [CQRS Eventual Consistency](https://banes-lab.com/records/tension/cqrs-eventual-consistency.md)

## referenced-by

- [Event-Driven Architecture](https://banes-lab.com/records/arch/event-driven-architecture.md)