Deadlock error

Question

Hi , iam geeting a dead log error from an autonomous trigger.
But in log file it show the same session nos'
DEADLOCK DETECTED ( ORA-00060 )
[Transaction Deadlock]
The following deadlock is not an ORACLE error. It is a
deadlock due to user error in the design of an application
or from issuing incorrect ad-hoc SQL. The following
information may aid in determining the deadlock:
Deadlock graph:
                       ---------Blocker(s)--------  ---------Waiter(s)---------
Resource Name          process session holds waits  process session holds waits
TX-00010003-00000459        16     188     X             16     188           X
session 188: DID 0001-0010-000021B4     session 188: DID 0001-0010-000021B4
Rows waited on:
Session 188: obj - rowid = 00002F8A - AAAC+KAAEAAACzcAAA
  (dictionary objn - 12170, file - 4, block - 11484, slot - 0)
Information on the OTHER waiting sessions:
End of information on OTHER waiting sessions.
Current SQL statement for this session:
UPDATE SUMMARY SET NAME = :B1 WHERE Mint_NAME = TO_CHAR(:B2 )
----- PL/SQL Call Stack -----
  object      line  object
  handle    number  name
1B5C1E9C       109  BF_AU_IP_TEST
1F957020      8352  package body  MINT
1B719024        19  package body ALOADER
1B7615E0         1  anonymous block
===================================================THIS IS MY AUTONOMOUS TRIGGER -BF_AU_IP_TEST
this trigger has the following update staetment
UPDATE SUMMARY SET NAME = :B1 WHERE Mint_NAME = TO_CHAR(:B2 )
Edited by: user8792751 on Aug 19, 2010 2:59 AM

Answer 1

Deadlock graph:
                       ---------Blocker(s)--------  ---------Waiter(s)---------
Resource Name          process session holds waits  process session holds waits
TX-00010003-00000459        16     188     X             16     188           Xyou have a TX (transaction) enqueue with exclusive mode (X) being held and exclusive mode(X) being waited on
Which means that two sessions are doing concurrent DML on the same target.
you have the sql statement involved in the deadlock and you have the row waited on
Rows waited on:
Session 188: obj - rowid = 00002F8A - AAAC+KAAEAAACzcAAAremember that an autonomous transaction when called represents a new session and then don't be surprised to observe deadlock in this situation.
But, please, let me know why you are
(a) using an autonomous transaction
(b) and using an autonomous transaction in trigger
I may help you to find another way to do your requirement
Regards
Mohamed Houri