> >I think it's easy to implement (I'm studying Interbase source code now)
>
> My final quibble for the moment. I'd be quite surprised if it were
> easy to implement, particularly in light of the blocking issues.

I think it's easy to implement if we left the programmer the risk to block
other threads.
So the programer can lock all other threads if launchs a long query in a
high priority.

Toni Martir