自治事务可能导致死锁，测试如下：

--1,测试表
create table test(x int,y int);

alter table test
  add constraint pk_test primary key(x);


create or replace procedure auto_proc(p_x int,p_y int) as
pragma autonomous_transaction;
begin
  insert into test(x,y) values(p_x,p_y);
  commit;
end;
/


--2，测试1,set autocommit off
Connected to Oracle Database 10g Enterprise Edition Release 10.2.0.1.0
Connected as bocnet@dev95
 
SQL> set timing on
SQL> set autocommit off
SQL> select * from test;

no rows selected

Elapsed: 00:00:00.00
SQL> insert into test(x,y) values(1,1);

1 row created.

Elapsed: 00:00:00.01
SQL> exec auto_proc(1,2);
BEGIN auto_proc(1,2); END;

*
ERROR at line 1:
ORA-00060: deadlock detected while waiting for resource
ORA-06512: at "BOCNET.AUTO_PROC", line 4
ORA-06512: at line 1


Elapsed: 00:00:03.10
SQL> select * from test;

         X          Y
---------- ----------
         1          1

Elapsed: 00:00:00.00
SQL> rollback;

Rollback complete.

Elapsed: 00:00:00.01

==>ORA-00060: deadlock,发现死锁后，自治事务被回退

==>alert_bocnet.log:

Wed Apr 15 11:17:29 2015
ORA-00060: Deadlock detected. More info in file /u01/app/oracle/product/10.2.0/db_1/admin/bocnet/udump/bocnet_ora_10394.trc.


--3，测试2,set autocommit on
Connected to Oracle Database 10g Enterprise Edition Release 10.2.0.1.0
Connected as bocnet@dev95
 
SQL> set autocommit on
SQL> set timing on   
SQL> select * from test;

no rows selected

Elapsed: 00:00:00.00
SQL> insert into test(x,y) values(1,1);

1 row created.

Commit complete.
Elapsed: 00:00:00.01
SQL>  exec auto_proc(1,2);
BEGIN auto_proc(1,2); END;

*
ERROR at line 1:
ORA-00001: unique constraint (BOCNET.PK_TEST) violated
ORA-06512: at "BOCNET.AUTO_PROC", line 4
ORA-06512: at line 1


Elapsed: 00:00:00.01
SQL> select * from test;

         X          Y
---------- ----------
         1          1

Elapsed: 00:00:00.00

==>ORA-00001: unique constraint,自治事务违反唯一约束被回退