Don't think it could be done with PBM, but you can solve this by creating a logon trigger, and in the trigger do a quick query on sys.dm_exec_sessions
, counting sessions with the original_login_name
same as suser_sname()
.
Beware that an error in login trigger could prevent all logins and render the instance unaccessible. To fix this, start the service in single user mode (-m).
Hope it helps.