From: "Lane Van Ingen" <lvaningen@esncc.com>
To: <pgsql-sql@postgresql.org>
Subject: Why Doesn't SQL This Expression Work?
Date: Mon, 22 Aug 2005 15:50:37 -0400
Message-ID: <EKEMKEFLOMKDDLIALABIAEKMCBAA.lvaningen@esncc.com>
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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.

The  result expected is a percentage, and should compute to 7.68 (8 as an
integer), when multiplied by 100. What is wrong here? Here is the result:
  Row  if_id in_count  time_incr  speed    possible_bytes  current_util_in
   1    2     589824    240        255840   7675200         0