>Be aware that in a multi-user environment there are some difficulties

and it

>is possible to miss some rows with this approach unless carefully
>implemented.

Thanks, everyone, all this advice is great!

It sounds like I possibly need an EventLog table, containing which posts
a 'new_event' event in the after insert trigger. The EventLog table can
contain things like EventType, SourceID, OldValue, NewValue,
DateTimeHandled.
I then just need to react to that one Firebird event, and check this
table to see what needs to be done.

I can then either delete he handled record out of my EventLog table, or
update the handled record and set the DataTimeHandled from null to Now.
Then, when there are no more null DateTimeHandled records, my app goes
back to sleep and waits for another event.

I guess I'd better do some tests to check whether the Event detection
component (FIBPlus/Delphi) is threaded, as two processing running
simultaneously would cause havoc here with this method too!

Thanks!
Maya