Jonathan Lewis wrote:
> <hasta_l3_at_hotmail.com> wrote in message
> news:1159000862.384129.73710_at_i3g2000cwc.googlegroups.com...
>> Dear group,
>>
>> Assume a transaction A with a single update statement updating many
>> rows of a table.
>> Assume another transaction B also with a single update, concurrently
>> updating the same rows, but perhaps in a different order.
>>
>> Can these single updates deadlock ?
>>
> If the row updates are in exactly the same
> order, the second transaction will wait for
> the first transaction to commit or rollback.
>
> If the row updates are in a different order
> you will get a deadlock.
>
>> How do you prevent this ?
>>
>
> a) Serialize the two updates
> b) Program for deadlock detection so that
> you can rollback and retry.
>
>> Thanks much.
Why not SELECT FOR UPDATE SKIP LOCKED?
--
Daniel Morgan
University of Washington
Puget Sound Oracle Users Group
Received on Sat Sep 23 2006 - 11:14:43 CDT
