Colin Rosenthal <[EMAIL PROTECTED]> writes:
> Hi all,
> We have an application which uses derby in auto-commit=false mode.
> For some reason a row in one of our tables cannot be updated from
> our system. Attempting to do so consistently produces a 40XL1 lock
> timeout error. I have shut down the system and gone in with ij and
> updated this row "by hand" without problem, but when I restart the
> system the row is still not updateable.
>
> Any ideas how to proceed?
The lock timeout error probably means there is a deadlock. This can
happen in cases where two transactions access the same resources in a
different order, like in
T1 accesses X before Y
T2 accesses Y before X
If T1 locks X and T2 locks Y, both transactions will wait for the
other transaction to release its lock.
You basically have two options:
1. Make sure that the transactions which cause deadlocks access rows
in the same order.
2. Deal with deadlocks in your code, i.e. catch exceptions and
restart the transactions.
--
Knut Anders
