Hello,
sorry for answering so late, ...
> I do not know if there is an specific error handler built in postgresql (besides error-codes).
>
> If you break the unique constraint an error will be thrown. A
> workaround may be to launch a trigger BEFORE the insertion and do whatever is necessary within the trigger.
>
This is possibillity I was thinking of, too. But if there are many
inserts and (probably) only a few of them would break the unique
constraint, there would be a great overhead. This was what I'd like to
avoid with a custom error handler.
Regards,
Verena