> --- In IBObjects@yahoogroups.com, Helen Borrie <helebor@...> wrote:
> >
> > At 04:08 AM 19/06/2007, you wrote:
> > >Hi all,
> > >
> > >Does tiCommitted isolation alone able to prevent lost update to
> > >happen? If not, how to prevent lost update using tiCommitted isolation?
> >
> > Please describe what you mean by "lost update".
> >
> for example, 2 transaction (TRA and TRB) start at the same time,
> reading the same row of a table. Then in TRB the row is updated and
> then committed. Then in TRA the same row is updated and committed. The
> update made in TRB is lost.
>
> Regards
>
> Tarno

then use tiConcurrency. TRA will be blocked, until it is able to see the
change in TRA.
BTW - all updates are lost by subsequent updates.
Alan