Command Query Responsibility Segregation (CQRS) is an architectural pattern that has evolved over the years, with roots in object-oriented programming (OOP) principles. The concept gained prominence in the software development community as a solution to complex system design challenges.

Pros:

1. Scalability: CQRS enables independent scaling of read and write operations, optimizing performance for specific workloads.

2. Flexibility: Separating read and write models allows tailoring each for its specific requirements, enhancing adaptability to evolving needs.

3. Improved Performance: By focusing on specific tasks, the pattern can lead to optimized read and write models, boosting overall system efficiency.

4. Better Domain Model: CQRS encourages a clearer representation of the domain model, aligning read and write models with their respective responsibilities.

Cons:

1. Complexity: Implementing CQRS introduces complexity, potentially increasing development and maintenance efforts.

2. Learning Curve: Developers need to grasp the nuances of separating read and write concerns, which may pose a learning challenge.

3. Eventual Consistency: Asynchronously updating read models may lead to eventual consistency, requiring strategies to handle potential discrepancies.

History:

In the early 2000s, Greg Young, a prominent figure in the software architecture space, played a pivotal role in formulating and promoting the CQRS pattern. Young's exploration of the pattern was driven by a need to address issues related to scalability, maintainability, and performance in large-scale systems.

The CQRS pattern draws inspiration from fundamental OOP principles, emphasizing the separation of concerns between commands that modify state and queries that retrieve data. This separation facilitates a more granular and specialized design, allowing for optimized handling of each responsibility.

Furthermore, the concept of Event Sourcing often goes hand in hand with CQRS, and contributors like Martin Fowler have explored its synergies. Event Sourcing involves capturing all changes to an application state as a sequence of events, providing a comprehensive audit trail, and enabling easy reconstruction of the system state at any point in time.

As the pattern gained popularity, other academics and practitioners contributed to its refinement and practical application. Prominent names include Udi Dahan, who extended CQRS to Distributed Systems, and Microsoft's Rinat Abdullin, who provided valuable insights into the implementation details of CQRS.

The CQRS pattern has found widespread adoption in various domains, from finance to e-commerce, due to its ability to address complex business requirements effectively. Its influence is evident in frameworks and libraries that support the implementation of CQRS, such as Axon Framework and Microsoft's CQRS Journey project.

In summary, the history of CQRS as an OOP pattern is marked by the collaborative efforts of visionaries like Greg Young, Martin Fowler, Udi Dahan, Rinat Abdullin, and others. Their contributions have shaped CQRS into a powerful and versatile architectural pattern, providing a robust foundation for building scalable and maintainable software systems.