Abstract: Systems, methods, and other embodiments for supporting high availability by using in-memory cache as a database are disclosed. In one embodiment, a system includes an application server that is configured to select a sub-set of data from a remote database that is predicted to be accessed by an application server, wherein the application server includes an in-memory cache. The sub-set of data is reformatted to reduce the size. The in-memory cache is configured to act as a backup database by pre-populating the reformatted sub-set of data into the in-memory cache. In response to detecting the remote database is in an off-line state: the in-memory cache is assigned as a primary database to replace the remote database and subsequent data requests are re-directed from being processed using the remote database to being processed using the in-memory cache.