How can I identify the rows involved in an Oracle deadlock?

Question

When Oracle detects a deadlock, a trace file like this is written:

*** SESSION ID:(56.27081) 2012-05-14 08:16:28.013
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-0010002c-002719b5       146      56     X            164      44           X
TX-000f002a-002edd1e       164      44     X            146      56           X
session 56: DID 0001-0092-00050D0D       session 44: DID 0001-00A4-0002E3C2
session 44: DID 0001-00A4-0002E3C2       session 56: DID 0001-0092-00050D0D
Rows waited on:
Session 44: obj - rowid = 00035157 - AAA1FXAAxAAASfLAAn
  (dictionary objn - 217431, file - 49, block - 75723, slot - 39)
Session 56: obj - rowid = 00035157 - AAA1FXAAsAACjuiAAP
  (dictionary objn - 217431, file - 44, block - 670626, slot - 15)

How can I determine the rows involved based on the information above in order to assist in debugging the application?

Answer 1

I found the answer:

1. The number after dictionary objn can be used to select out of DBA_objects.

   SELECT owner, object_name, object_type 
   FROM dba_objects 
   WHERE object_id = 217431;
   

2. Once the table is identified, the row can be found using the rowid:

   SELECT * 
   FROM table_found_above 
   WHERE rowid = 'AAA1FXAAxAAASfLAAn';
   

If the trace file says that there are no "Rows waited on" this technique will not work. The problem may be due to an unindexed foreign key.