Oracle’s Universal Connection Pool (UCP) provides a feature called connection labeling where an application could attach arbitrary name/value pairs to a connection.By associating particular labels with particular connection states, an application can retrieve an already initialized connection from the pool and avoid the time and cost of re-initialization. The initialization varies and could include simple state re-initialization that requires method calls within the application code or database operations that require round trips over the network.
Connection labeling is application-driven and requires the application to implement an callback interface called oracle.ucp.ConnectionLabelingCallback. The callback determines whether or not a connection with a requested label already exists. If no connections exist, the interface allows current connections to be configured as required.