Database And Interface Modifications: Change Management Without Affecting The Clients

The first Oracle®-based Controls Configuration Database (CCDB) was developed in 1986, by which the controls system of CERN’s Proton Synchrotron became data-driven. Since then, this mission-critical system has evolved tremendously going through several generational changes in terms of the increasing complexity of the control system, software technologies and data models. Today, the CCDB covers the whole CERN accelerator complex and satisfies a much wider range of functional requirements. Despite its online usage, everyday operations of the machines must not be disrupted. This paper describes our approach with respect to dealing with change while ensuring continuity. How do we manage the database schema changes? How do we take advantage of the latest web deployed application development frameworks without alienating the users? How do we minimize impact on the dependent systems connected to databases through various APIs? In this paper we will provide our answers to these questions, and to many more.