Seamless Database Evolution for Cloud Applications.

We present DECA (Database Evolution in Cloud Applications), a framework that facilitates fast, robust, and agile database evolution in cloud applications. Successful business requires to react to changing wishes and requirements of customers instantly. In today's realities, this often boils down to adding new features or fixing bugs in a software system. We focus on cloud application platforms that allow seamless development and deployment of applications by operating both the old and the new version in parallel for the time of development/deployment. This does not work if a common database is involved, since they cannot co-exist in multiple versions. To overcome this limitation, we apply current advances in the field of agile database evolution. DECA equips developers with an intuitive Database Evolution Language to create a new co-existing schema version for development and testing. Meanwhile, users can continuously use the old version. With the click of a button, we migrate the database to the new version and move all the users without unpredictable downtime and without the risk of corrupting our data. So, DECA speeds up the evolution of information systems to the pace of modern business. p>