Subject Re: Triggers suitability
Author yeohray
Thanks for the information. Is it possible to retrieve this 'record
version' value? I was thinking if it could be used to detect changes
to records (related to my question on avoiding pessimistic locking).

Ray Mond

-- In, "Ann W. Harrison"
<aharrison@i...> wrote:
> Firebird uses multi-generational concurrency control. That means
> when you modify a record, Firebird creates a new version of the
> and keeps the old one around so that other transactions can
continue to
> see it. When you delete a record, Firebird creates a new record
> that says that the record is deleted, leaving the old record
> When your transaction commits and all transactions that were
> with it end, the old versions become uninteresting - useless
garbage in
> fact. All transactions (and a garbage collect thread) remove
> unnecessary old versions of records as they are encountered.
> Regards,
> Ann