There is a new command in 11g to display the current events, which is oradebug eventdump.
For instance :
SQL> alter session set events '10046 trace name context forever,level 12:942 trace name ERRORSTACK level 3'; SQL> oradebug setmypid Statement processed. SQL> oradebug eventdump session sql_trace level=12 942 trace name ERRORSTACK level 3
Read metalink note 436036.1
In 10g and before, the command was oradebug dump events 1 and the list was dumped in a trace file, 11g directly outputs to the console.
Note there is no backward compatibility with unsupported tools like oradebug.
In 11g you will get an ORA-76 with dump events
SQL> oradebug setmypid Statement processed. SQL> oradebug dump events 1 ORA-00076: dump EVENTS not found $ oerr ora 76 00076, 00000, "dump %s not found" // *Cause: An attempt was made to invoke a dump that does not exist. // *Action: Type DUMPLIST to see the list of available dumps.