Subject Re: New TPB constant usage
Author slalom91
--- In firebird-support@yahoogroups.com, "Ann W. Harrison"
<aharrison@...> wrote:
>
> slalom91 wrote:
> > Hi,
> >
> > Can someone provide me the ideal transaction parameters for my
> > purposes. I have a multi-threaded, multi-user application which
> > amounts to an order entry system.
> >
>
> Different people will have different answers and different
> answers are appropriate in different circumstances.
>
> I would argue for isc_tpb_concurrency and take the defaults
> on everything else. That gives each transaction a consistent
> view of data.
>
> When one transaction attempts to update or delete a record
> that was inserted, updated, or deleted by a concurrent
> transaction, it will wait until the second transaction completes.
> That behavior avoids a problem called live-lock where two
> transactions attempt to update the same records, both fail,
> both retry, both fail, and the process continues forever at
> great expense.
>
> If there is relatively low contention but transactions
> are long - requiring user input while open for example - you
> might use isc_tpb_nowait to get an instant error on update
> conflicts.
>
> Regards,
>
>
> Ann
>

thanks Ann