Database Migration of Schemas Enforced by Applications without Downtime

摘要

Techniques supporting database migration of schemas enforced by applications without downtime is described. In examples, a method of migrating databases is described to comply with schemas enforced by one or more applications without downtime such that the data remains accessible to the one or more applications. A transformation is initiated, by a schema migration module implemented by one or more computing devices, of a first database in compliance with a first schema into a second database in compliance with a second schema. The first and second schemas have mechanisms for storage and retrieval of data that is modeled using at least one technique other than a relational model. Access of the one or more applications is controlled by the schema migration module to the first and second databases during the transformation by limiting read operation access to the second database and write operation access to the first database during the transformation and synchronizing write operations made to the first database by replaying the write operations with corresponding transformed data into the second database.