When a service provider (SP) is configured to use account linking for an identity provider (IdP) connection, by default PingFederate uses the built-in Hyper SQL Database (HSQLDB) as the account-link repository. You can also configure PingFederate to store account links on an external database server or directory server. For specific instructions on how to configure these options, see the following topics:

Use the built-in HSQLDB only for trial or training environments. For testing and production environments, always use a secured external storage solution for proper functioning in a clustered environment.

Testing involving HSQLDB is not a valid test. In both testing and production, it might cause various problems due to its limitations and HSQLDB involved cases are not supported by PingIdentity.