Error with transaction

Question

Hi!
An error has occurred! Why are you transfer money from my card again? I paid 9 735 HKD for all (mac mini, mouse, keyboard and adapter). But then you transferred money again! 738 HKD and 370 HKD for that? Can you comment this?
Order Number: W226194711
login: [email protected]

Answer 1

The 8177 error does not seem to be a rarity when using transaction isolation serializable...
Yes, if you elect to use serializable you can just about bet that ORA-8177 will, at some point, come along for the ride. It is just a "fact of life" when using serializable (including "false positives"). The only way to avoid it (as far as I know) is to not use serializable. If this is not possible, then the application will have to deal with it in some fashion.
It is relatively easy to demonstrate that you can get the error using SQL*Plus. On one of my test systems, the following reliably raises ORA-8177:
Session 1:
SQL> create table test (a number, b number);
Table created.
SQL> insert into test values (1,1);
1 row created.
SQL> commit;
Commit complete.
SQL> begin
  2    -- use serializable for this test
  3    set transaction isolation level serializable;
  4
  5    -- sleep for 10 seconds to perform actions in session 2
  6    dbms_lock.sleep(10);
  7
  8    -- this will likely fail with ORA-8177
  9    update test set b = 2 where a = 1;
10  end;
11  /
While the anonymous pl/sql block is executing...
Session 2:
SQL> insert into test values (2,2);
1 row created.
SQL> commit;
Commit complete.
Now, back in Session 1...
begin
ERROR at line 1:
ORA-08177: can't serialize access for this transaction
ORA-06512: at line 9I'm not sure what you mean about using serializable to push concurrency problems into the database.
Regards,
Mark
[EDIT]
Also, I believe index block splits during the serializable transaction can also result in ORA-8177...