#📝 Note: CQRS (Command Query Responsibility Segregation)

#Overview

CQRS is a pattern that separates read and update operations for a data store. Implementing CQRS in your application can maximize its performance, scalability, and security.

#Core Idea

• Command: Changes the state of a system (Write).
• Query: Returns a result without changing the state (Read).

#Why Use CQRS?

• Independent Scaling: Read and write workloads often have different performance characteristics.
• Optimized Schemas: The read store can use a schema optimized for queries (e.g., Elasticsearch), while the write store uses a schema optimized for updates (e.g., PostgreSQL).
• Simplified Security: Easier to manage who can change data vs. who can read it.

#Trade-offs

• Complexity: Managing two separate data models and keeping them in sync.
• Eventual Consistency: There is usually a delay between a write and when it appears in the read store.