On Mon, 22 Aug 2005, Lane Van Ingen wrote: > Hi, am trying to do a simple computation on two views, but for some reason > the current_util_in computation always returns zero. All fields being used > are integer. > > select a.if_id, > a.in_count, > a.time_incr, > b.speed, > ((a.time_incr * b.speed) / 8) as possible_bytes, > (a.in_count / ((a.time_incr * b.speed) / 8) * 100) AS current_util_in, > from if_history_view1 a, speed_history_view1 b > where a.if_id = b.if_id > and a.if_id = 2; > > The inner computation (a.time_incr * b.speed / 8) evaluated properly to > 7675200. > Add the "in_count divide operation", and the result is zero.
Integer division doesn't follow all the same rules as normal division would. In particular (a/b)*c is not the same as a*c/b. Also, I think you may be expecting rounding rather than truncation (and in the case of (a.time_incr*b.speed)/8 can that not be a multiple of 8, and if so what should happen?) ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
