MySQL 9.0 Release Notes
        
          Given a Performance Schema thread ID, returns the
          user_name@host_name
- in_thread_id BIGINT UNSIGNED: The thread ID for which to return the account. The value should match the- THREAD_IDcolumn from some Performance Schema- threadstable row.
mysql> SELECT sys.ps_thread_account(sys.ps_thread_id(CONNECTION_ID()));
+----------------------------------------------------------+
| sys.ps_thread_account(sys.ps_thread_id(CONNECTION_ID())) |
+----------------------------------------------------------+
| root@localhost                                           |
+----------------------------------------------------------+