SQL> create table process_data (
  2    process_date date default sysdate);

Table created.

SQL> create table events (
  2    event_code char(1));

Table created.

SQL> 
SQL> create bitmap index events_code_bi on events(event_code);

Index created.

SQL> 
SQL> insert into process_data values (default);

1 row created.

SQL> commit;

Commit complete.

-- session1
SQL> 
SQL> doc
DOC>  ===== session1 =====
DOC>#
SQL> update process_data
  2   set process_date=default;

1 row updated.

SQL> 
SQL> pause T1 Press return
T1 Press return

-- session2
SQL> doc
DOC>  ===== session2 =====
DOC>#
SQL> insert into events values('x');

1 row created.

SQL> 
SQL> pause T2 Press return
T2 Press return

-- session1
SQL> pause T1 Press return
T1 Press return

SQL> 
SQL> insert into events values('x');

-- session2
SQL> pause T2 Press return
T2 Press return

SQL> 
SQL> update process_data
  2   set process_date=default;

-- session1
SQL> insert into events values('x');
insert into events values('x')
            *
ERROR at line 1:
ORA-00060: deadlock detected while waiting for resource

DEADLOCK DETECTED ( ORA-00060 )
See Note 60.1 at My Oracle Support for Troubleshooting ORA-60 Errors
[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-0002000C-000074D3-00000000-00000000         73     131     X             74      42           X
TX-00050017-00007453-00000000-00000000         74      42     X             73     131           S
 
session 131: DID 0001-0049-00000622     session 42: DID 0001-004A-00000337 
session 42: DID 0001-004A-00000337      session 131: DID 0001-0049-00000622 
 
Rows waited on:
  Session 131: no row
  Session 42: obj - rowid = 00035055 - AAA1BVAAGAAAJSmAAA
  (dictionary objn - 217173, file - 6, block - 38054, slot - 0)
 
----- Information for the OTHER waiting sessions -----
Session 42:
  sid: 42 ser: 63710 audsid: 3901823815 user: 666/TC
    flags: (0x100045) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40009) -/-/INC
  pid: 74 O/S info: user: oracle, term: UNKNOWN, ospid: 870833
    image: oracle@localhost
  client details:
    O/S info: user: oracle, term: pts/54, ospid: 12332
    machine: localhost program: sqlplus@localhost (TNS V1-V3)
    application name: SQL*Plus, hash value=3669949024
  current SQL:
  update process_data
   set process_date=default
 
----- End of information for the OTHER waiting sessions -----
 
Information for THIS session:
 
----- Current SQL Statement for this session (sql_id=0619xrd492p25) -----
insert into events values('x')

ISSUE DETECTED (Most Recent):
Located in section containing "DEADLOCK DETECTED ( ORA-00060 )" in tracefile :
    ora12_ora_870830.trc

Deadlock graph:
                                          ---------Blocker(s)--------  ---------Waiter(s)---------
Resource Name                             process session holds waits  process session holds waits
TX-0002000C-000074D3-00000000-00000000         73     131     X             74      42           X
TX-00050017-00007453-00000000-00000000         74      42     X             73     131           S
 
End of Deadlock Graph


ERROR: ORA-00060 Deadlock Graph with >1 Row, at Least 1 Row is "TX X S" 

SOLUTION:
There are 2 primary causes of deadlocks with this signature: bitmap indexes or
ITL contention.
 The 2 types can be identified by whether any of the objects involved in the 
query are bitmap indexes or not.
The "#### Objects That May Be Involved In The Deadlock ####" section in the 
output below can help you to identify whether bitmap indexes are involved in 
the query. 


Bitmap Index Deadlocks: 

If the object ids retrieved from the trace identify a bitmap index then the
likelihood is that the problem is related to this as opposed to ITLs. When 
bitmap indexes are used, multiple rows are covered by the same bitmap index 
fragment. If these rows are locked in different orders then you can encounter
deadlocks. Look at the application to check that the order rows are dealt 
with is consistent. 

If any of the objects are Bitmap Indexes then there is a high likelihood that 
this is a bitmap index issue. 

SQL> create table process_data (
  2    process_date date default sysdate);

Table created.

SQL> create table events (
  2    event_id char(1) primary key);

Table created.

SQL> 
SQL> insert into process_data values (default);

1 row created.

SQL> commit;

Commit complete.

-- session1
SQL> 
SQL> doc
DOC>  ===== session1 =====
DOC>#
SQL> update process_data
  2   set process_date=default;

1 row updated.

SQL> 
SQL> pause T1 Press return
T1 Press return

-- session2
SQL> doc
DOC>  ===== session2 =====
DOC>#
SQL> insert into events values('x');

1 row created.

SQL> 
SQL> pause T2 Press return
T2 Press return

-- session1
SQL> pause T1 Press return
T1 Press return

SQL> 
SQL> insert into events values('x');

-- session2
SQL> pause T2 Press return
T2 Press return

SQL> 
SQL> update process_data
  2   set process_date=default;

-- session1
SQL> pause T1 Press return
T1 Press return

SQL> 
SQL> insert into events values('x');
insert into events values('x')
            *
ERROR at line 1:
ORA-00060: deadlock detected while waiting for resource

DEADLOCK DETECTED ( ORA-00060 )
See Note 60.1 at My Oracle Support for Troubleshooting ORA-60 Errors
[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-00080013-00006E0A-00000000-00000000         78      32     X             80      44           X
TX-00020009-00007533-00000000-00000000         80      44     X             78      32           S
 
session 32: DID 0001-004E-00000178      session 44: DID 0001-0050-00000123 
session 44: DID 0001-0050-00000123      session 32: DID 0001-004E-00000178 
 
Rows waited on:
  Session 32: no row
  Session 44: obj - rowid = 0003505D - AAA1BdAAGAAAJS+AAA
  (dictionary objn - 217181, file - 6, block - 38078, slot - 0)
 
----- Information for the OTHER waiting sessions -----
Session 44:
  sid: 44 ser: 150 audsid: 119456786 user: 666/TC
    flags: (0x100045) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40009) -/-/INC
  pid: 80 O/S info: user: oracle, term: UNKNOWN, ospid: 36995
    image: oracle@localhost
  client details:
    O/S info: user: oracle, term: pts/74, ospid: 20920
    machine: localhost program: sqlplus@localhost (TNS V1-V3)
    application name: SQL*Plus, hash value=3669949024
  current SQL:
  update process_data
   set process_date=default
 
----- End of information for the OTHER waiting sessions -----
 
Information for THIS session:
 
----- Current SQL Statement for this session (sql_id=0619xrd492p25) -----
insert into events values('x')