How to take 100s of local Oracle Databases and consolidate them on the cloud into a single database, retaining only access to local data for each location (answer: VPD) and with multiple releases of applications and databases running side by side (answer: Editions). A critical platform rejuvenation.
Dozens of Oracle Databases - each health center location has one on its local server with the same data model and the same set of applications. These databases have to be centralized and cloudified and also be consolidated into one or as few databases as possible. To lower costs, ease operations and enable innovation. Each location can access only its own data, applications do not have to be changed and different locations can run different versions of applications and database objects. This is the story of a critical migration. About the cloud ready analysis, the Proofs of Concept with Oracle Database features VPD and Edition Based Redefinition, the scalability investigation, the redesign of change management, rollout and operational management processes and the careful modernization of a 25 year old platform on the latest database release and a shiny new, fully automated cloud platform.
This is the story of an organization that had state of the art systems in the mid-90s. And they have these same systems today - no longer state of the art. They can keep the systems alive, but barely, and at increasing cost. In the Fall of 2020, we started an investigation into the feasibility of bringing the 100s of databases from each of the locations together, in a central location, in the cloud and finally: consolidated into one or at least as few database instances as possible. Using Oracle Database Virtual Private Database and Edition Based Redefinition, a smart database connection configuration in each store and a limited reimplementation of non-cloud/non-consolidated mechanisms (interaction with local file system for example) we have designed and proven a working new design and migration approach.