Zero-Downtime Schema Evolution in Distributed Databases: A Theoretical Framework

This paper aims to present a theoretical framework for implementing zero downtime schema changes in distributed environments based on formal consistency models and distributed systems theory. Using the CAP theorem, we examine existing approaches and introduce a new methodology for making seamless schema transitions while keeping the system available and consistent. We formalize the schema transition problem using the theory of state machine replication and design algorithms for the coordination of schema evolution across the distributed nodes. Our experimental results show that the proposed framework improves the performance by up to 87% for the transition related impacts when compared to the traditional methods, with no service downtime at all.