> sometimes when I need to change the database object - view/procedure - this error is raised.
>
> Can I detect which user/transaction causing this problem?

Maybe something like:

select distinct a.mon$user
from mon$statements s
join mon$attachments a on s.mon$attachment_id = s.mon$attachment_id
where s.mon$sql_text containing <view/procedure name>
and s.mon$transaction_id <> current_transaction

could give you an indication as to who could be using the object?

HTH,
Set