> I am trying to
> find the most elegant way to get the Firebird server to periodically
> run a stored procedure (e.g every hour). I don't want to rely on any
> external application to periodically invoke the stored procedure.

Forget the most elegant way, there is no way at all to do this without
relying on an external application. Fortunately, such a program exists
on every platform Firebird is delivered to. On Windows, it is called
"Scheduled Tasks". It may be set to run a script in iSQL (or run any
client app for that matter) at whatever time and frequency you like.

Part of the problem for the Firebird engine is that there is no
specific requirement to 'register' a database to an engine instance.
The schedule would need to be stored in a separate database (the same
way that the security database is distinct from your data). You would
need to set it up for each server anyway, and if you are going to that
much trouble, why not just use the OS feature?

If you are less caring about the precise time and precise frequency,
and the cleanup was reasonably quick, then perhaps you could put
triggers on Transaction Start.

Adam