During restoration of database in test environment we face below issue once database gets set too single user mode.
Only user processes can be killed. Database is already open and can only have one user at a time.
Nothing worked from below steps.
-We tried to kill all session.
-We tried to put database offline.
-We tried to put database in multiuser mode.
-We tried database files attach-detach.
-We tried to wait till system process gets released still sessions not getting released.
-Last option : Restart database server which is not feasible each time.
Hoping for better assistance as issue seems not getting resolved with any available option except restart.