strings $ORACLE_HOME/bin/oracle > oracle.strings
vi oracle.strings
	All events are around 61% in vi (for Oracle 9.2)


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Errors in setting event and how to correct them.


***** minor error 214:

SQL> alter session set events = 'immediate trace name trace_buffer_on, level 4';
ERROR:
ORA-02194: event specification syntax error 230 (minor error 214) near ','

--No level is needed
SQL> alter session set events = 'immediate trace name trace_buffer_on';

Session altered.


SQL> alter session set events 'immediate trace name buffers, level 1';
ERROR:
ORA-02194: event specification syntax error 230 (minor error 214) near ','

--No comma is needed
SQL> alter session set events 'immediate trace name buffers level 1';

Session altered.

--The following is what Steve Adams's book p.108 says:
SQL> alter session set events = 'immediate trace name heapdump_addr 80682060';
ERROR:
ORA-02194: event specification syntax error 230 (minor error 214) near '80682060'

--Missing level
SQL> alter session set events = 'immediate trace name heapdump_addr level 4, addr 80682060';

Session altered.




***** minor error 215:

SQL> alter session set events '10046 trace name context forever level 12';
ERROR:
ORA-02194: event specification syntax error 230 (minor error 215) near 'LEVEL'

--Comma is needed
SQL> alter session set events '10046 trace name context forever, level 12';

Session altered.




***** minor error 286:

SQL> alter session set events = '60 trace name deadlock';
ERROR:
ORA-02194: event specification syntax error 231 (minor error 286) near 'DEADLOCK'

--"Deadlock" is not a trace name, but an event name
SQL> alter session set events = 'deadlock trace name context';

Session altered.


SQL> alter session set events = 'immediate trace name row_cacheee level 12';
ERROR:
ORA-02194: event specification syntax error 231 (minor error 286) near 'ROW_CACHEEE'

--Wrong spelling of trace name
SQL> alter session set events = 'immediate trace name row_cache level 12';

Session altered.


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How to find an event that was set in a session or system-wide?

To find in a session:
oradebug setorapid <v$process.pid>
oradebug dump events 1
(On UNIX/Linux, setorapid,setospid both work. But on Windows, setorapid is
better to avoid hanging. If you want to see what event was set in your current
session, dbms_system.read_ev also works.)

To find events set system-wide:
oradebug setmypid
oradebug dump events 4

Event name, ID and level are recorded in the trace file.

Note: Using alter system to set an event only sets events in a future session. To
set it in currently connected sessions, oradebug setorapid... or dbms_system.set_ev.


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How to set multiple events on one line?

alter system set events '980 trace name errorstack forever: 942 trace name errorstatck forever';

You can only do that once; subsequent errorstack events won't have any effect.
So putting them on one line is needed. To turn them off:

alter system set events '980 trace name errorstack off: 942 trace name errorstatck off';