how an app can know when a table is altered ?

i'm developing a framework (mod_perl+apache) that reads the db-schema and
automatically explode html forms.

now i read the schema and cache it into perl-hashes to speedup things.

my problem is to recognize when a table is altered so that the framework can
update the related forms connected to the db tables.
i don't want to read the schema every time (now i must restart apache, and i
don't want to restart ...)

It's possible? How can i implement this ?

Thank you,

valter
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com