Trace obtained enqueue information by set event 10704

Oracle事件10704可以帮助我们了解队列Enqueue的使用情况，使用方法如下:

[oracle@rh2 bdump]$ oerr ora 10704
10704, 00000, "Print out information about what enqueues are being obtained"
// *Cause:  When enabled, prints out arguments to calls to ksqcmi and
//          ksqlrl and the return values.
// *Action: Level indicates details:
//   Level: 1-4: print out basic info for ksqlrl, ksqcmi
//          5-9: also print out stuff in callbacks:  ksqlac, ksqlop
//          10+: also print out time for each line

SQL> oradebug setmypid;
Statement processed.

SQL> oradebug event 10704 trace name context forever,level 10;
Statement processed.

SQL> lock  table tm in share mode;
Table(s) Locked.

SQL> oradebug tracefile_name;
/s01/admin/G10R2/udump/g10r2_ora_28400.trc

ksqgtl *** CU-9fec6e30-00000000 mode=6 flags=0x10 timeout=300 ***
ksqgtl: no transaction
ksqgtl: use existing ksusetxn DID
ksqgtl:
        ksqlkdid: 0001-0017-00000008
*** 2011-05-07 21:17:16.139
*** ksudidTrace: ksqgtl
        ksusesdi:   0000-0000-00000000
        ksusetxn:   0001-0017-00000008
ksqgtl: RETURNS 0
*** 2011-05-07 21:17:16.160
ksqrcl: CU,9fec6e30,0
ksqrcl: returns 0
*** 2011-05-07 21:17:23.884
ksqgtl *** CU-9fec69f8-00000000 mode=6 flags=0x10 timeout=300 ***
ksqgtl: no transaction
ksqgtl: use existing ksusetxn DID
ksqgtl:
        ksqlkdid: 0001-0017-00000008
*** 2011-05-07 21:17:23.884
*** ksudidTrace: ksqgtl
        ksusesdi:   0000-0000-00000000
        ksusetxn:   0001-0017-00000008
ksqgtl: RETURNS 0
*** 2011-05-07 21:17:23.898
ksqrcl: CU,9fec69f8,0
ksqrcl: returns 0
*** 2011-05-07 21:17:23.899
ksqgtl *** TM-0000d06b-00000000 mode=4 flags=0x401 timeout=21474836 ***
ksqgtl: xcb=0xa69d0a00, ktcdix=2147483647, topxcb=0xa69d0a00
        ktcipt(topxcb)=0x0
*** 2011-05-07 21:17:23.899
ksucti: init txn DID from session DID 0001-0017-00000008
ksqgtl:
        ksqlkdid: 0001-0017-00000008
*** 2011-05-07 21:17:23.899

*** ksudidTrace: ksqgtl
        ktcmydid(): 0001-0017-00000008
        ksusesdi:   0000-0000-00000000
        ksusetxn:   0001-0017-00000008
ksqgtl: RETURNS 0

该10704事件可以配合10046事件一起诊断异常的队列锁问题，记以录之！