Abstract: Systems and methods are provided to enable a partial migration of applications from one database system to another without modifying the applications. In embodiments, a proxy server is configured to monitor the application's usage of a current database, and generate a migration plan to partially migrate database objects used by the application to a different type of database. An object may be selected for migration based on its usage level or its portability. After the partial migration, the proxy server may remain in place as a request router to route the application's requests to the two databases. In embodiments, the migration system may forward queries to both databases and compare the query results received from the two. Based on the comparison results, the migration system may programmatically determine adjustments to its query handling configuration settings.