--- In firebird-support@yahoogroups.com, Raymond Kennington
<progsol@c...> wrote:

> Why is it permitted to be done if it is not possible to backup and
> restore the database?

Raymond, I don't know answer for this question, but I have another
one - why you are so persistent in aspiration for usage of evidently
most ineffective usage of RDBMS? Besides unpredictable restorability
computed column of this kind are subqueries and are defeated by joins.
I think this is the reason why nobody can help you - simply nobody use
it.

Best regards, Alexander.