Subject Re: [IBO] More on record locking
Author Jason Wharton
> I have read in other posts that 'true' client server applications
> don't use record locking.
> How then does one prevent a user from changing a record that is being
> changed by another user in an interactive application?
> For example, a user is updating a customer name. Another user
> decides to change the address. If there is no record locking how do
> you prevent the loss of one of the changes?

What is meant by locking is doing something "in order to" change a record.
In InterBase you just change the record. By doing that, this prevents
another person from changing the record with a deadlock exception as soon as
they try.

This is called optimistic concurrency.

To make it pessimistic (like PDOX, etc.) is all you have to do with
InterBase is perform a dummy update to the record and that effectively locks
it from being modified by another user. This is what IBO does for you
automatically if you set the PessimisticLocking property to true.

Jason Wharton
CPS - Mesa AZ